JP4547233B2 - Communication system, communication method and program thereof - Google Patents

Description

  The present invention relates to a communication system, a communication method, and a program for each terminal to confirm the intention of another terminal in a full mesh network constructed by connections between the terminals.

  Conventionally, in a system such as a multi-person chat in which a plurality of entities (eg, terminals) participate and join on an IP network, a community temporarily composed of a plurality of entities is constructed, and each entity is Exchange application data.

  At this time, each entity must have some kind of relationship (called a connection) in order to set up a session for transmitting and receiving data, and there are a plurality of models for constructing the connection.

  A generally popular model is a model that uses a server that manages a connection as a component other than a community entity, and each entity constructs a connection only with that server (referred to as a central model).

  However, this central model requires a separate server in addition to each entity, and not only for the providers providing the above systems and services, but also for those who build their own systems in terms of management, operation, and maintenance costs. Introduction is difficult.

  In the central model, in order to manage connections with one server, if a failure occurs in that server, all connections in all communities built using that server will be disconnected, so communication will be interrupted. Will occur. That is, the central model is a system that is very vulnerable to a single point of failure, and can be said to have low availability.

  Here, availability refers to availability, and is generally measured by the degree to which a system is hard to break, the difficulty of a failure, the repair speed when a failure occurs, and the like. Speaking of a highly available system, it refers to a system that rarely fails and can be used safely at any time. On the other hand, a system with low availability means a system that frequently fails and does not recover easily.

  Furthermore, in the central model, since connections are collectively managed by a server, in many cases, application data is once sent to the server, and after data processing such as mixing is performed, it is sent to other entities. This type of data transmission / reception method is suitable for applications where the amount of data is relatively small and applications that do not require strict real-time characteristics. It is inappropriate for applications that require real-time performance.

  On the other hand, as a connection model, there is a full mesh type model in which connections between entities are directly constructed in a full mesh. Unlike the central model, this model has no required components, except for entities that join and join the community. In other words, there is no need for a server that collectively manages connections, and each entity manages a plurality of connections instead.

  In addition, since the management of connections is distributed to each entity, the availability is higher than that of the central model. As a result, even if a failure occurs in an entity, the effect is minimized, and communication of the entire community is not cut off. Furthermore, in this model, since the application data is often transmitted directly to the entity without passing through the server, it is suitable for an application that requires strict real-time property.

  By the way, in a multi-point communication application that forms a community, there are many events in which a new entity joins or joins (referred to as a new entity) or an entity that already joins or joins leaves. At this time, when considering security in the community, it is necessary for the new entity to participate and join after obtaining permission from the community to join and join the community.

  In the full mesh model, entity authentication between entities can be performed by existing technologies such as electronic signatures, but access control when a new entity joins or joins the community is very difficult. This is because there is no entity having the right of participation / subscription access control for the new entity. In the case of the central model, for example, it can be realized by providing a centralized access control function to a server that collectively manages connections.

  If there is no centralized access control function, that is, there is a flat relationship between the various authorities among the entities in the community, whether or not a new entity can join / subscribe multiple The method of deciding by the approval or disapproval of the entity can be considered (unanimous or majority approval).

  In this case, various processes (permissions such as a process for generating votes, a process for distributing votes to each entity, a process for collecting votes for each entity's approval and disapproval, and a process for determining whether or not an entity can participate / subscribe with the vote) The decision process must be done by the entity. However, even if entity authentication is performed between the entities, it is impossible to predict what kind of fraud the entities will cause during these processes. Authentication is considered to only provide the ability to identify an entity.

  Therefore, in the full mesh model, there is no entity that all entities can trust, so it is difficult to generate fraudulent votes, distribute fraudless votes, collect fraudless votes, etc. It is difficult to guarantee that the vote has been made and the correct procedure has been taken.

  In addition, since the full mesh model cannot directly know the exchanges between other entities in the community, one entity performs a permission decision process (such as generation and distribution of votes) for participation / subscription for new entities. After the decision process, when the new entity accesses and establishes a connection to each entity that has already joined or joined the community, the entity that has received the access will perform each process in the authorization decision process safely and without fraud It is difficult to reliably know that the new entity has permission from other entities.

Here, fraud is, for example, when an entity 1 and entity 2 that do not perform fraud are considered to be unable to participate / subscribe without obtaining unanimous agreement from an entity that has joined / subscribed to a community. The former is against the participation and participation of the community of the new entity, and when the latter is in favor, the new entity agrees that Entity 2 is unanimously due to fraud by entities other than Entity 1 and Entity 2. It is to make it seem to have obtained (refer nonpatent literatures 1-6).
Henry Sinnreich, Alan B. Johnson (Author), Katsuhiko Sakaguchi (Translation), “Mastering TCP / IP SIP,” Ohm Corporation Oct. 2002, Chapter 12 J. Lennox, H. Schulzrinne, "A Protocol for Reliable Decentralized Conforencing" ACM International Workshop on Network and Operating Systems Support for Digital Audio and Video (NOSSDAV), Monterry, California, June 2003. A. Shamir, "How to share a secret," Communications of the ACM, page 612-613, 1979. P. Feldman, "A practical scheme for non-interactive verifiable secret sharing." InProc. 28th IEEE Symposium on Foundations of Computer Science (FOCS '87), pages 427-437, IEEE Computer Society, 1987. TPPedersen, "Non-interactive and information-theoretic secure verifiable secret sharing." In Advances in Cryptology? CRYPTO '91, volume 576 of Lecture Notesin Computer Science, pages 129-140, Berlin, 1992.Springer-Verlag. Tatsuaki Okamoto, Hiroshi Yamamoto, “Contemporary Cryptography Series / Mathematics of Information Science,” P.217 Sangyo Tosho Publishing, July 1997.

  However, the conventional techniques described above have the following problems to be solved.

  In the above-described full mesh model, since there is no centralized access control organization, a plurality of entities that have already joined or joined a community determine the decision of joining or joining a new entity to the community by voting. In this case, however, the permission decision process had to be carried out by multiple entities.

  In addition, even if entity authentication is performed using an authentication technique such as electronic signature, the behavior of the entity is unpredictable, so in the full mesh model, all entities are assumed to be trusted in the end. It is difficult. For this reason, it is difficult to generate a vote without fraud, distribute a vote without fraud, collect a vote without fraud, and so on. It was difficult to guarantee.

  Further, in a full mesh connection, since the exchange between other entities in the community cannot be directly known, it is difficult for other entities to directly know the behavior of the entity. Therefore, when a permission determination process is performed and a connection is established between a new entity and an entity that has already joined or joined the community, the permission determination process is performed safely without any unauthorized processing. It was difficult for each entity to know for sure that they had permission from the other entities.

  The present invention has been made in view of the above-described problems, and the object of the present invention is to approve or reject by a plurality of entities that have already joined the community when a new entity joins or joins a community based on a full mesh network. Can control access by the vote, detect unauthorized entities that exist in the authorization decision process, prevent unauthorized manipulation of the authorization decision process, and new entities have already joined and joined the community. When establishing a connection for each entity, the authorization decision process can be performed safely and without fraud, and other entities participating in or joining the community agree or disagree with the participation or participation of the new entity in the community. (Allowed) Interview Nikeshon system, to provide a communication method and a program.

  In order to solve the problem, claim 1 of the present invention communicates with a plurality of terminals or public key servers connected to a network, and establishes a connection with the plurality of terminals to establish a community. A full-mesh network formed by a full-mesh connection between two or more terminals, the communication system for obtaining a public key by a public key acquisition request to the public key server A request is made to invite a new terminal that does not belong to the community and a new terminal that does not belong to the community, or a request that a new terminal that does not belong to the community belongs to the community. A reception terminal configured by any of the terminals belonging to the community; Information that is the basis for creating voting information for deciding whether or not to join / subscribe when a new terminal joins / joins a member terminal composed of terminals belonging to the community other than the end And when a new terminal requests each of the member terminals to establish the connection, whether the new terminal has obtained approval for the participation / subscription from the member terminal and the receiving terminal of the community. A permission information generation module for generating permission information, which is information for confirmation, and connection establishment information necessary for the reception terminal to confirm whether a new terminal has established the connection with the member terminal The connection establishment information generation module to be generated and the permission generated independently by each of the member terminals. Information is distributedly encoded by the verifiable secret sharing (k, n) threshold method (k ≦ n) to generate n permission information shares and one permission information share verification information as voting information, and the like All terminals that are distributed and encoded with the secret sharing method (k, n) threshold method (k ≦ n), generate n connection establishment information shares, and participate in or join the community in the same manner When the number is 3 or more, the destination information of the new terminal is distributedly encoded by the verifiable secret sharing (k, n) threshold method (k ≦ n) to verify n destination information shares and one destination information share. VSS share coding module for generating information for use, and (k, n) threshold method of the secret sharing method or the verifiable secret sharing method to obtain k or more shares from n distributed coded shares By using the original information The VSS decryption module for restoring information, the permission information share verification information and the destination information share verification information are used, and the permission information share, the connection establishment information share, and the destination information share are illegal by VSS. The permission information generated by the permission information generation module, and the VSS distributed code, the share verification module for checking whether or not there is a common key generation module for generating a session key by a common key encryption method The permission information share that is generated using the authentication module and the permission information, the permission information share verification information, the connection establishment information that is generated by the connection establishment information generation module, the VSS distributed encoding module, and the The connection establishment information generated using the connection establishment information Share, a session key generated by the common key generation module, a public key of a terminal other than the terminal acquired by inquiring the public key server, a secret key and a public key of the terminal, and another terminal The destination information share generated using the VSS distributed encoding module and the destination information, the destination information share verification information, and all terminals participating in or joining the community A database managing the terminal list, and when the new terminal requests each of the member terminals to establish the connection, the member terminal agrees with the terminal from the other terminals belonging to the community. The permission information share acquired from the new terminal and the permission managed in the database of the own terminal. A permission information comparison module for comparing and confirming permission information restored using the information share, the VSS decryption module, and permission information managed in the database of the own terminal; When the connection is received from the new terminal, whether or not the connection is established with all the member terminals, the connection establishment information share acquired from the new terminal and the connection managed by the database of the own terminal A connection establishment information comparison module for comparing and confirming the connection establishment information restored using the establishment information share, the VSS decoding module, and the connection establishment information managed in the database of the terminal itself; To encrypt information that has been requested for encryption using public key encryption The conversion result of multiple information is the same as the public key encryption module for the public key, the common key encryption module for encrypting the requested information using the common key encryption system A digest generation module for generating a digest of arbitrary information using a message digest function, which is a kind of hash function that is difficult to become, and decryption of the information requested to be decrypted by a public key encryption method Whether to establish a connection with a public key encryption scheme decryption module for decrypting information, a common key encryption scheme decryption module for decrypting information requested for decryption with a common key encryption scheme, and Determination of the approval and disapproval of participation / subscription of the new terminal to the community, and participation / addition of the new terminal to the community A decision input module for making a final decision on approval or disapproval for admission and a decision on whether to join or join the community, a message with the requested content, and a request to generate the message In the case of attaching the information passed from time to time to the message, when the electronic signature and encryption are applied to the message, the public key encryption method encryption module, the common key encryption method module, and the digest generation module are used. On the other hand, if only the encryption is performed, a message generation module for executing the attachment with the common key cryptosystem module, and requesting the permission information generation module to generate the permission information, The connection establishment information generation module generates the connection establishment information. Requesting the VSS distribution to generate the permission information share, the permission information share verification information, or the connection establishment information share, or the destination information share, and the destination information share verification information. Request the encoding module, request the public key cryptosystem encryption module to encrypt the permission information share with the public key, and decrypt the encrypted permission information share with the public key cryptosystem decryption module Requesting the intention input module to make the decision, requesting the VSS decryption module to restore the destination information from the destination information share, and comparing the permission information to the permission information comparison Requesting the module to compare the connection establishment information to the connection establishment information comparison module. Request the common key generation module to generate the application key, request the share verification module to check whether the permission information share or the destination information share is illegal, and inquire and store various information in the database to generate the message. A control module for requesting the module to generate the message, and for all terminals, a digest included in the message to confirm whether fraudulent activity has been performed during transmission / reception of the received message. A message fraud determination module for comparing whether the digest generated by the digest generation module is different from the content of the message and the content of the message, and the electronic signature and encryption of the received message for all terminals If the When the message is decrypted with the key encryption system decryption module and the common key encryption system decryption module, and the public key of the source terminal necessary for decrypting the message is not stored in the database In order to request the public key server to obtain a public key through the control module, and to check whether the message is fraudulent after the decryption process, the content of the obtained message The digest is generated by the digest generation module with the content of the message from the digest, and the two digests are passed to the message fraud determination module, and confirmation of the presence or absence of fraud is requested. The message content, while the message A message analysis module for decrypting the message by the common key encryption method decryption module and passing the content of the message after the decryption to the control module; A message processing module for transmitting the message generated by the message generation module to an external terminal or the public key server, and passing the message received from the external terminal or the public key server to the message analysis module; .

  Also, in the present invention described in claim 2, the permission information generation module according to claim 1, wherein the permission information generation module includes the time information at the time of generation, the destination information of the new terminal, and an arbitrary random keyword. And generate.

  In addition, according to a third aspect of the present invention, in the first or second aspect, the connection establishment information generation module is configured to generate the connection establishment information, time information at the time of generation, and the destination information of the new terminal. And arbitrary random keywords.

  In addition, in the present invention described in claim 4, in any one of claims 1 to 3, when the total number of terminals is two, the reception terminal can join the member terminal to the community of the new terminal. The member terminal asks for approval / disapproval of the subscription, and based on the permission information generated independently in the case of approval, the VSS distributed coding module uses the threshold information (3, 3) for the three permission information shares as voting information. Generating and distributing one of them to the receiving terminal, and when the member terminal approves in the first stage, the member terminal shares one permission information share of its own terminal The second stage of determining whether or not to allow the new terminal to participate in or join the community is submitted as an approval vote to the receiving terminal, and the member terminal is in favor of the second stage. In this case, the permission terminal shares two permission information shares, one of which is collected as an approval vote from the member terminal and one of the reception terminal, into the new terminal. Provided as a ticket for joining, and when the new terminal establishes the connection with the member terminal, attaches all the permission information shares acquired from the receiving terminal to a message for requesting establishment of the connection Or when the total number of terminals is three or more, the receiving terminal asks all the member terminals to approve or disagree with the participation / subscription of the new terminal to the community. Based on the permission information generated independently, the member terminal uses the VSS distributed coding module as a threshold ((total number of terminals), (total number of terminals)) (all (Number of terminals) number of permission information shares and one piece of permission information share verification information are generated, and (number of all terminals) out of the number of permission information shares of (number of all terminals). Distribute one each to all the other member terminals and the receiving terminal, and simultaneously distribute the permission information share verification information, and all the member terminals agree in the first stage. If there is, each of the member terminals submits the permission information share (total number of terminals -2) acquired from all the other member terminals to the corresponding terminal as an approval vote, so that the new terminal In the second stage, and when all the member terminals are in favor in the second stage, the receiving terminal is in favor of all the member terminals. As recovered (Total number of terminals−1) × (total number of terminals−1) × (total number of terminals−1) × (total number of terminals−1) ) Obtained permission information shares as tickets for joining / subscribing to the community to the new terminal, and obtained from the corresponding terminal when the new terminal establishes the connection with each of the member terminals The permission information share is added to a message for requesting establishment of the connection as a third stage.

  Further, in the present invention according to claim 5, in the claim 4, in the case where each of the member terminals distributes the permission information share in the case of the first stage, when the total number of terminals is two, the member The terminal distributes one of the three permission information shares generated by its own terminal to the corresponding terminal, one is a vote for its own terminal, and the other one of the permission information shares is sent to other terminals. When managing all without leaking and the total number of terminals is three or more, each of the member terminals is (total number of terminals minus one) among the permitted information shares generated by the own terminal (total number of terminals) The information is distributed to other terminals, and the remaining one of the permission information share and the permission information is managed without leaking to the other terminals.

  Further, in the present invention described in claim 6, when the member terminal submits the permission information share to the reception terminal in claim 5, or the permission acquired by the reception terminal from each of the member terminals. When providing the information share to the new terminal, the information is encrypted and submitted by the public key cryptosystem encryption module using the public key of the new terminal including the destination information of the own terminal.

  Further, in the present invention described in claim 7, in any one of claims 4 to 6, in the second stage, when all the member terminals have submitted a vote in favor to the reception terminal, The connection establishment information is generated by the connection establishment information generation module, and the connection establishment information is distributedly encoded by the VSS distributed encoding module with threshold values ((total number of terminals), (total number of terminals)). Of the connection information shares of (total number of terminals), (total number of terminals −1) is provided to all the member terminals one by one, and the remaining one connection establishment information share and its original The connection establishment information which is information is managed by the database without leakage to the outside.

  The invention according to claim 8 is the case where the member terminal receives a message indicating the connection establishment request attached with the permission information share from the new terminal according to any one of claims 4 to 7. In order to check whether the new terminal receives approval for participation / subscription from all terminals belonging to the community other than its own terminal, the permission information comparison module receives the permission information from the control module. When the comparison request is received and the total number of terminals is two, the two permission information shares attached to the connection establishment request message and the one permission information share managed in the database of the own terminal The permission information is restored by the VSS decryption module and stored in the database of the terminal itself. If there is no difference, the difference between the time information included in the permission information and the time information at the time of comparison is greater than or equal to a predetermined value set in advance. If it is less than the predetermined value, it is further checked whether the destination information is different from the new terminal. If there is no difference, a normal response is returned to the control module, and the total number of terminals is three or more. In the case of (1), among the (total number of terminals −1) × (total number of terminals −1) of the permission information shares attached to the connection establishment request message, the own terminal distributed (total number of terminals −1). The permission information is restored by the VSS decryption module using the permission information shares and the one permission information share managed in the database of the terminal, and is stored in the database of the terminal. Before If there is no difference, it is checked whether or not the difference between the time information included in the permission information and the time information at the time of comparison is equal to or greater than the predetermined value. If it is equal to or smaller than the predetermined value, it is further checked whether the destination information is different from the new terminal. If there is no difference, the remaining (total number of terminals−2) × (total number of terminals−1) Whether or not the permission information share is illegal is confirmed by using the permission information share verification information acquired at the time of distribution of the permission information share from the share verification module and the other member terminals. A normal response is returned to the control module.

  The present invention described in claim 9 further comprises permission information validity period setting means for arbitrarily setting the predetermined value indicating the validity period of the permission information.

  Further, in the present invention according to claim 10, in any one of claims 8 and 9, the new terminal transmits a message indicating the connection establishment request to each of the member terminals, and the connection is normally established. Each of the member terminals provides the connection establishment information share stored in the database by the own terminal, and the new terminals are obtained from all the member terminals (total number of terminals −1). Including the connection establishment information share, and providing the connection terminal with the connection terminal in order to confirm whether or not the new terminal has established the connection with all the member terminals. The comparison module receives a request for comparison of the connection establishment information from the control module and acquires it from the new terminal (all end Number-1) connection establishment information shares, one connection establishment information share managed in the database of its own terminal, and the connection establishment information restored using the VSS decoding module, The connection establishment information managed in the database of the terminal is compared to check whether there is a difference. If there is no difference, the time information included in the connection establishment information and the comparison It is checked whether or not the difference from the time information is equal to or greater than the predetermined value. If the difference is equal to or smaller than the predetermined value, a normal response is returned to the control module.

  The present invention described in claim 11 further comprises connection establishment information validity period setting means for arbitrarily setting the predetermined value indicating the validity period of the connection establishment information.

  Further, in the present invention described in claim 12, in any one of claims 4 to 11, the response terminal asks each of the member terminals for approval or disapproval for participation / subscription of the new terminal to the community. The member terminal is notified as the destination information of the new terminal that wishes to invite or join / subscribe, and when the total number of terminals is three or more, the destination information of the new terminal is the VSS distributed coding The destination information share obtained by distributed encoding by the module and the destination information share verification information are notified, and each of the member terminals acquires the destination information share acquired from the reception terminal in order to obtain the original destination information. All of the destination information with the destination information share verification information and the share verification module acquired from the reception terminal. To restore the original of the destination information by the VSS decryption module after verifying the fraud share.

  Further, in the present invention described in claim 13, when the member terminal submits the permission information share as an approval vote in any one of claims 4 to 12, the permission information share is changed to the permission information share. The share verification module checks whether the verification information is fraudulent.

  In addition, in the present invention according to claim 14, in any one of claims 4 to 13, in the first stage, the reception terminal joins the community of the new terminal notified from all the member terminals In response to a request for approval or disapproval of the subscription, a totaling result indicating whether or not it is possible to proceed to the second stage for the voting is notified, and the voting result is notified in the second stage.

  The present invention according to claim 15 communicates with a plurality of terminals or public key servers connected to a network, and establishes a connection with the plurality of terminals to form a community, And a communication method for acquiring a public key by a public key acquisition request to the public key server, wherein the community is formed by a full mesh connection between two or more of the terminals. A step of forming a network and a request for inviting a new terminal that does not belong to the community to the community, or a new terminal that does not belong to the community belongs to the community. Configuring with any of the terminals belonging to the community that received the request; For determining whether to participate or join when a new terminal joins or joins the community by the step of configuring a mobile terminal with a terminal belonging to the community other than the receiving terminal and the permission information generation module Information that is the basis for creating voting information, and when a new terminal requests each of the member terminals to establish the connection, the new terminal participates from the member terminal and the receiving terminal of the community. A step of generating permission information, which is information for confirming whether or not approval for subscription has been obtained, and whether or not a new terminal has established the connection with the member terminal by the connection establishment information generation module; Of generating connection establishment information necessary for confirmation , The VSS distributed encoding module distributes and encodes the permission information generated independently by each of the member terminals by the verifiable secret sharing (k, n) threshold method (k ≦ n), and outputs n pieces of voting information. A permission information share and one permission information share verification information are generated, and similarly connection establishment information is distributedly encoded by the secret sharing method (k, n) threshold method (k ≦ n), and n pieces of connection establishment information are obtained. Similarly, when the total number of terminals participating in or joining the community is 3 or more, the destination information of the new terminal is obtained by the (k, n) threshold method (k ≦ n) of the verifiable secret sharing A distributed encoding, generating n destination information shares and one destination information share verification information, and a (k, n) threshold of the secret sharing method or the verifiable secret sharing by a VSS decryption module A step of restoring original information by using k or more shares from n distributed coded shares by a value method; and the permission information share verification information and the destination information share by a share verification module A step of confirming whether the permission information share, the connection establishment information share, and the destination information share are illegal by using VSS, and a session key by a common key encryption method by a common key generation module; Generating the permission information generated by the permission information generation module using the database, the VSS distributed coding module and the permission information share generated using the permission information, and Authorization information share verification information and the connection generated by the connection establishment information generation module Inquiry to the public key server, the connection establishment information share generated by using the connection establishment information, the VSS distributed encoding module and the connection establishment information, the session key generated by the common key generation module, and the public key server Generated by using the public key of the other terminal other than the own terminal acquired in the above, the private key and public key of the own terminal, the destination information of the other terminal, the VSS distributed encoding module, and the destination information. Managing the destination information share, the destination information share verification information, and a terminal list covering all terminals participating in or joining the community, and a permission information comparison module, whereby the new terminal When the member terminal is requested to establish the connection, the new terminal in the member terminal Whether the approval is obtained from another terminal belonging to the tee, the permission information share acquired from the new terminal, the permission information share managed in the database of the own terminal, and the VSS decoding module, When the response terminal receives access from the new terminal by the step of comparing and confirming the permission information restored using and the permission information managed in the database of the own terminal, and the connection establishment information comparison module Whether the connection has been established with all the member terminals, the connection establishment information share acquired from the new terminal, the connection establishment information share managed by the database of the own terminal, and the VSS decoding module And the connection establishment information restored using A step of comparing and confirming connection establishment information managed in a database, a step of encrypting information requested by the public key encryption method using a public key encryption method encryption module, and a common key A step of encrypting information requested to be encrypted by a common key encryption method by an encryption method encryption module and a hash function in which conversion results of a plurality of information are difficult to be the same by a digest generation module A step of generating a digest of arbitrary information using a message digest function which is a type of the above, and a step of decrypting information requested for decryption by a public key encryption method decryption module by a public key encryption method And the information received by the common key encryption method decryption module into the common key encryption method A step of further decryption, a decision input module to determine whether to establish the connection, a primary decision on the approval or disapproval of participation / subscription of the new terminal to the community, and participation of the new terminal in the community A final decision on whether or not to participate and a decision on whether or not to join / subscribe to the community; a message generation module generates a message of the requested content, and generation of the message In the case of attaching the information passed at the time of the request to the message and applying the electronic signature and encryption to the message, the public key encryption module, the common key encryption module, the digest generation module, While performing the attachment, while applying only the encryption. In this case, the step of executing the attachment with the common key cryptosystem module, and the control module requests the permission information generation module to generate the permission information, and the connection establishment information generation module generates the connection establishment information. The VSS to generate the permission information share, the permission information share verification information, or the connection establishment information share, or the destination information share, and the destination information share verification information. Request the distributed encoding module, request the public key cryptosystem encryption module to encrypt the permission information share with the public key, and decrypt the encrypted permission information share with the public key cryptosystem decryption Ask the module to ask the intention input module to make the decision, The VSS decoding module is requested to restore the destination information from the destination information share, the permission information comparison module is requested to compare the permission information, and the connection establishment information comparison is performed to the connection establishment information comparison module. Request the common key generation module to generate the session key, request the share verification module to perform fraud checks on permission information share or destination information share, and inquire and store various information in the database. A step of requesting the message generation module to generate the message and a message fraud determination module for confirming whether or not fraudulent activity has been performed during transmission / reception of the received message for all terminals. The digest included in the message And whether the digest generated by the digest generating module is different from the content of the message and the content of the message, and the received message is digitally signed and encrypted for all terminals by the message analyzing module. The message is decrypted by the public key encryption system decryption module and the common key encryption system decryption module, and further, the source terminal required for decrypting the message If the public key is not stored in the database, the public key server is requested to acquire the public key through the control module, and it is confirmed whether or not the message is fraudulent after the decryption process. In order to do so from the content and digest of the obtained message A digest is generated by the digest generation module based on the message content, two digests are passed to the message fraud determination module, and confirmation of the presence or absence of fraud is requested. If there is no fraud, the message content is passed to the control module. On the other hand, if the message is only encrypted, decrypting the message by the common key encryption method decryption module, and passing the content of the decrypted message to the control module; The message processing module transmits the message generated by the message generation module to an external terminal or the public key server, and passes the message received from the external terminal or public key server to the message analysis module. And having.

  Further, in the present invention described in claim 16, in claim 15, the permission information generation module is configured to generate the permission information, time information at the time of generation, the destination information of the new terminal, and an arbitrary random keyword. And generate.

  Further, the present invention according to claim 17 is the connection establishment information generation module according to any one of claims 15 and 16, wherein the connection establishment information includes the time information at the time of generation and the destination information of the new terminal. And arbitrary random keywords.

  Further, in the present invention described in claim 18, in any one of claims 15 to 17, when the total number of terminals is two, the reception terminal can join the member terminal to the community of the new terminal. The member terminal asks for approval / disapproval of the subscription, and based on the permission information generated independently in the case of approval, the VSS distributed coding module uses the threshold information (3, 3) for the three permission information shares as voting information. Generating and distributing one of them to the receiving terminal, and when the member terminal approves in the first stage, the member terminal shares one permission information share of its own terminal A second step of submitting as an approval vote to the receiving terminal and determining whether or not the new terminal is to participate in or join the community, and the member terminal agrees in the second step If the answering terminal has received the permission information share, which is a combination of the one collected by the receiving terminal from the member terminal as an approval vote and the one held by the receiving terminal, to the new terminal to the community Provided as a ticket for joining / subscribing, and when the new terminal establishes the connection with the member terminal, all the permission information shares acquired from the receiving terminal are used as a message for requesting establishment of the connection. A third stage to be attached, or in the case where the total number of terminals is three or more, the receiving terminal asks all the member terminals for approval or disapproval for participation / subscription of the new terminal to the community, Each of the member terminals is thresholded by the VSS distributed coding module based on the permission information generated independently ((total number of terminals), (total number of terminals)). (The total number of terminals) pieces of the permission information share and one piece of the permission information share verification information are generated, and (the total number of terminals) out of the (total number of terminals) pieces of the permission information. Each share is distributed to all the other member terminals and the receiving terminal, and the permission information share verification information is distributed at the same time as the first stage. In the first stage, all the member terminals In the case of approval, each of the member terminals submits the permission information share (total number of terminals−2) acquired from all the other member terminals to the reception terminal as approval votes, Deciding whether to join or join a new terminal to the community is the second stage, and when all the member terminals are in favor in the second stage, the receiving terminal is sent from all the member terminals. In favor (Total number of terminals−2) × (total number of terminals−1) and (total number of terminals−1) × (total number of terminals−1) × (total number of terminals) -1) providing the permission information share to the new terminal as a ticket for joining / subscribing to the community, and when the new terminal establishes the connection with each of the member terminals, the corresponding terminal The third stage is to attach all the permission information shares acquired from the message to the message for requesting establishment of the connection.

  Further, in the present invention according to claim 19, in the claim 18, in the case where each of the member terminals distributes the permission information share when the number of all terminals is two, The terminal distributes one of the three permission information shares generated by its own terminal to the corresponding terminal, one is a vote for its own terminal, and the other one of the permission information shares is sent to other terminals. When managing all without leaking and the total number of terminals is three or more, each of the member terminals is (total number of terminals −1) among (the total number of terminals) of the permitted information shares generated by the own terminal The information is distributed to other terminals, and the remaining one of the permission information share and the permission information is managed without leaking to the other terminals.

  In addition, the present invention described in claim 20 provides the permission obtained in claim 19 when the member terminal submits the permission information share to the receiving terminal, or the receiving terminal acquires from each of the member terminals. When providing the information share to the new terminal, the information is encrypted and submitted by the public key cryptosystem encryption module using the public key of the new terminal including the destination information of the own terminal.

  Further, in the present invention described in claim 21, in any one of claims 18 to 20, in the second stage, when all the member terminals have submitted a vote of approval to the reception terminal, The connection establishment information is generated by the connection establishment information generation module, and the connection establishment information is distributedly encoded by the VSS distributed encoding module with threshold values ((total number of terminals), (total number of terminals)). Of the connection information shares of (total number of terminals), (total number of terminals −1) is provided to all the member terminals one by one, and the remaining one connection establishment information share and its original The connection establishment information which is information is managed by the database without leakage to the outside.

  The present invention according to claim 22 is the case where the member terminal receives a message indicating the connection establishment request attached with the permission information share from the new terminal according to any of claims 18 to 21. In order to check whether the new terminal receives approval for participation / subscription from all terminals belonging to the community other than its own terminal, the permission information comparison module receives the permission information from the control module. When the comparison request is received and the total number of terminals is two, the two permission information shares attached to the connection establishment request message and the one permission information share managed in the database of the own terminal The VSS decryption module restores the permission information and uses the database of its own terminal. If there is no difference, the difference between the time information included in the permission information and the time information at the time of comparison is greater than or equal to a predetermined value set in advance. If there is no difference between the destination information and the new terminal, a normal response is returned to the control module, and the total number of terminals is 3 If there are more than two, the own terminal has distributed (total number of terminals− of the total number of terminals−1) × (total number of terminals−1) of the permission information shares attached to the connection establishment request message. 1) Using the one permission information share and one permission information share managed in the database of the own terminal, the permission information is restored by the VSS decoding module, and is stored in the database of the own terminal. Save Whether or not there is a difference from the permission information, and if there is no difference, whether or not the difference between the time information included in the permission information and the time information at the time of comparison is greater than or equal to the predetermined value. If it is less than the predetermined value, it is further checked whether the destination information is different from the new terminal. If there is no difference, the remaining (total number of terminals−2) × (total number of terminals−1) Whether or not the permission information share is illegal is confirmed using the permission information share verification information acquired at the time of distribution of the permission information share from the share verification module and the other member terminals. If not, a normal response is returned to the control module.

  In addition, the present invention described in claim 23 comprises, in claim 22, a permission information valid period setting means for arbitrarily setting the predetermined value indicating the validity period of the permission information.

  According to a twenty-fourth aspect of the present invention, in any one of the twenty-second or twenty-third aspect, the new terminal transmits a message indicating the connection establishment request to each of the member terminals, and the connection is normally established. Each of the member terminals provides the connection establishment information share stored in the database by the own terminal, and the new terminals are obtained from all the member terminals (total number of terminals −1). Including the connection establishment information share of the connection terminal, and providing the reception terminal with the connection establishment information to confirm whether the new terminal has established the connection with all the member terminals. The comparison module receives a request for comparison of the connection establishment information from the control module, and obtains it from the new terminal ( Number of terminals-1) connection establishment information share, one connection establishment information share managed in the database of its own terminal, and connection establishment information restored using the VSS decoding module Is compared with the connection establishment information managed in the database of its own terminal to check whether there is a difference. If there is no difference, the time information included in the connection establishment information is compared with It is checked whether or not the difference from the time information is equal to or larger than the predetermined value. If the difference is equal to or smaller than the predetermined value, a normal response is returned to the control module.

  According to a twenty-fifth aspect of the present invention, in the twenty-fourth aspect, there is provided connection establishment information valid period setting means for arbitrarily setting the predetermined value indicating the validity period of the connection establishment information.

  According to a twenty-sixth aspect of the present invention, in any one of the eighteenth to twenty-fifth aspects, the receiving terminal asks each of the member terminals whether or not the new terminal participates in or joins the community. The member terminal is notified as the destination information of the new terminal that wishes to invite or join / subscribe, and when the total number of terminals is three or more, the destination information of the new terminal is the VSS distributed coding The destination information share obtained by distributed encoding by the module and the destination information share verification information are notified, and each of the member terminals acquires the destination information share acquired from the reception terminal in order to obtain the original destination information. All the destinations with the destination information share verification information and the share verification module acquired from the receiving terminal. By the VSS decryption module after verifying the incorrect distribution share to restore the original the destination information.

  Further, in the present invention of claim 27, in any of claims 18 to 26, when the member terminal submits the permission information share as an approval vote, the permission information share is changed to the permission information share. The share verification module checks whether the verification information is fraudulent.

  In addition, in the present invention according to claim 28, in any one of claims 18 to 27, in the first stage, the reception terminal has joined the community of the new terminal notified from all the member terminals. In response to a request for approval or disapproval for the subscription, the result of counting whether or not it is possible to proceed to the second stage for the voting is notified, and the result of the voting is notified in the second stage.

  The present invention according to claim 29 communicates with a plurality of terminals or public key servers connected to a network, and establishes a connection with the plurality of terminals to form a community, And a communication program for obtaining a public key by a public key acquisition request to the public key server, wherein the community is formed by a full mesh connection between two or more of the terminals. A step of forming a network and a request for inviting a new terminal that does not belong to the community to the community, or a new terminal that does not belong to the community belongs to the community. A step configured by one of the terminals belonging to the community that has received the request. And a step of configuring a member terminal with a terminal belonging to the community other than the reception terminal, and a permission information generation module, when a new terminal participates in or joins the community, determines whether to participate or join. Information for creating voting information for the new terminal, when the new terminal requests establishment of the connection to each of the member terminals, the new terminal receives information from the member terminal and the reception terminal of the community. Generating permission information, which is information for confirming whether or not approval for the participation / subscription is obtained, and whether or not a new terminal has established the connection with the member terminal by a connection establishment information generation module; A service that generates connection establishment information necessary for the receiving terminal to check And the VSS distributed coding module, the permission information generated independently by the member terminals is distributedly encoded by the verifiable secret sharing (k, n) threshold method (k ≦ n), and used as voting information. n permission information shares and one permission information share verification information are generated, and connection establishment information is similarly distributedly encoded by the (k, n) threshold method (k ≦ n) of the secret sharing method, A connection establishment information share is generated. Similarly, when the total number of terminals participating / subscribing to the community is 3 or more, the destination information of a new terminal is converted to the verifiable secret sharing (k, n) threshold method (k ≦ n) to perform distributed encoding and generate n destination information shares and one destination information share verification information, and a VSS decryption module to execute the secret sharing method or the verifiable secret sharing (k, n) a step of restoring original information by using k or more shares from n distributed coded shares by a threshold method, and the permission information share verification information and the destination by a share verification module Using information share verification information, confirming whether the permission information share, the connection establishment information share, and the destination information share are illegal by VSS, and by using a common key encryption method by a common key generation module Generating a session key, and using the database, the permission information generated by the permission information generation module, the permission information share generated using the VSS distributed encoding module and the permission information, Generated by the permission information share verification information and the connection establishment information generation module By inquiring the connection establishment information, the connection establishment information share generated using the VSS distributed encoding module and the connection establishment information, the session key generated by the common key generation module, and the public key server. The destination generated using the public key of the terminal other than the own terminal to be acquired, the private key and public key of the own terminal, the destination information of the other terminal, the VSS distributed encoding module, and the destination information Managing the information share, the destination information share verification information, and a terminal list that covers all terminals participating in or joining the community; and a permission information comparison module that allows the new terminal to be the member When requesting establishment of the connection to each of the terminals, the new terminal in the member terminal Whether the approval is obtained from another terminal belonging to the community, the permission information share acquired from the new terminal, the permission information share managed in the database of the own terminal, and the VSS decoding module, When the response terminal receives access from the new terminal by the step of comparing and confirming the permission information restored using and the permission information managed in the database of the own terminal, and the connection establishment information comparison module Whether the connection has been established with all the member terminals, the connection establishment information share acquired from the new terminal, the connection establishment information share managed by the database of the own terminal, and the VSS decoding module And the connection establishment information restored using A step of comparing and confirming connection establishment information managed by the database, and a step of encrypting information requested by the public key encryption method encryption module using a public key encryption method. The step of encrypting the information requested to be encrypted by the key encryption method encryption module by the common key encryption method, and the hash that makes it difficult for the conversion result of the plurality of information to be the same by the digest generation module Generate a digest of arbitrary information using a message digest function, which is a kind of function, and decrypt the requested information using the public key encryption method by the public key encryption method decryption module Step and the common key encryption method decryption module Decrypting according to the method, determination by the intention input module whether to establish the connection, primary determination of approval / disapproval for participation / subscription of the new terminal to the community, and determination of the new terminal to the community A final decision on whether or not to participate / subscribe and a decision on whether or not to join / subscribe to the community; and a message generation module generates a message of the requested content; When attaching the information passed at the time of the generation request to the message, and applying the electronic signature and encryption to the message, the public key encryption module, the common key encryption module, and the digest generation module And execute the attachment with the encryption When the attachment is performed using the common key encryption module, the control module requests the permission information generation module to generate the permission information, and the connection establishment information is generated by the connection information. Requesting the generation module to generate the permission information share, the permission information share verification information, or the connection establishment information share, or the destination information share, and the destination information share verification information. Request the VSS distributed encoding module, request the public key cryptography encryption module to encrypt the permission information share with a public key, and decrypt the encrypted permission information share with the public key cryptosystem Ask the decryption module and ask the intention input module to make the decision. Requesting the VSS decoding module to restore the destination information from the destination information share, requesting the permission information comparison module to compare the permission information, and comparing the connection establishment information to the connection establishment information comparison. Request to the module, request the common key generation module to generate the session key, request the share verification module to perform fraud check on permission information share or destination information share, A step of saving and requesting the message generation module to generate the message, and a message fraud determination module confirming whether or not fraudulent activity has been performed during transmission / reception of the received message for all terminals. In order to Comparing the digest generated from the digest and the digest generated by the digest generating module with the message generating module, and the message analyzing module using the message analyzing module The message is decrypted by the public key encryption system decryption module and the common key encryption system decryption module, and further, the source terminal required for decrypting the message If the database does not have the public key, the request is made to the public key server through the control module to obtain the public key, and after the decryption process, the message is checked for fraud. To get the message content and digest The digest generation module generates a digest with the contents of the message, passes the two digests to the message fraud determination module, requests confirmation of the presence of fraud, and if there is no fraud, sends message content to the control module. On the other hand, when the message is only encrypted, the message is decrypted by the common key encryption method decryption module, and the content of the decrypted message is passed to the control module. The message processing module transmits the message generated by the message generation module to an external terminal or the public key server, and the message received from the external terminal or public key server is sent to the message analysis module. Pass Tep.

  In addition, in the present invention described in claim 30 according to claim 29, the permission information generation module includes the permission information, time information at the time of generation, the destination information of the new terminal, and an arbitrary random keyword. And generate.

  Further, in the present invention according to claim 31, in any one of claim 29 or 30, the connection establishment information generation module is configured to generate the connection establishment information, time information at the time of generation, and the destination information of the new terminal. And arbitrary random keywords.

  Further, in the present invention described in claim 32, in any one of claims 29-31, when the total number of terminals is two, the reception terminal makes the member terminal join the community of the new terminal. The member terminal asks for approval / disapproval of the subscription, and based on the permission information generated independently in the case of approval, the VSS distributed coding module uses the threshold information (3, 3) for the three permission information shares as voting information. Generating and distributing one of them to the receiving terminal, and when the member terminal approves in the first stage, the member terminal shares one permission information share of its own terminal A second step of submitting as an approval vote to the receiving terminal and determining whether or not the new terminal is to participate in or join the community, and the member terminal agrees in the second step If the answering terminal has received the permission information share, which is a combination of the one collected by the receiving terminal from the member terminal as an approval vote and the one held by the receiving terminal, to the new terminal to the community Provided as a ticket for joining / subscribing, and when the new terminal establishes the connection with the member terminal, all the permission information shares acquired from the receiving terminal are used as a message for requesting establishment of the connection. A third stage to be attached, or in the case where the total number of terminals is three or more, the receiving terminal asks all the member terminals for approval or disapproval for participation / subscription of the new terminal to the community, Each of the member terminals is thresholded by the VSS distributed coding module based on the permission information generated independently ((total number of terminals), (total number of terminals)). (The total number of terminals) pieces of the permission information share and one piece of the permission information share verification information are generated, and (the total number of terminals) out of the (total number of terminals) pieces of the permission information. Each share is distributed to all the other member terminals and the receiving terminal, and the permission information share verification information is distributed at the same time as the first stage. In the first stage, all the member terminals In the case of approval, each of the member terminals submits the permission information share (total number of terminals−2) acquired from all the other member terminals to the reception terminal as approval votes, Deciding whether to join or join a new terminal to the community is the second stage, and when all the member terminals are in favor in the second stage, the receiving terminal is sent from all the member terminals. In favor (Total number of terminals−2) × (total number of terminals−1) and (total number of terminals−1) × (total number of terminals−1) × (total number of terminals) -1) providing the permission information share to the new terminal as a ticket for joining / subscribing to the community, and when the new terminal establishes the connection with each of the member terminals, the corresponding terminal The third stage is to attach all the permission information shares acquired from the message to the message for requesting establishment of the connection.

  Further, in the present invention according to claim 33, in the claim 32, the first step is that when each of the member terminals distributes the permission information share and the total number of terminals is two, the member The terminal distributes one of the three permission information shares generated by its own terminal to the corresponding terminal, one is a vote for its own terminal, and the other one of the permission information shares is sent to other terminals. When managing all without leaking and the total number of terminals is three or more, each of the member terminals is (total number of terminals minus one) among the permitted information shares generated by the own terminal (total number of terminals) The information is distributed to other terminals, and the remaining one of the permission information share and the permission information is managed without leaking to the other terminals.

  Further, in the present invention described in claim 34, in the claim 33, when the member terminal submits the permission information share to the reception terminal, or the permission terminal acquired from each of the member terminals. When providing the information share to the new terminal, the information is encrypted and submitted by the public key cryptosystem encryption module using the public key of the new terminal including the destination information of the own terminal.

  Further, in the present invention described in claim 35, in any one of claims 32 to 34, in the second stage, when all the member terminals have submitted a vote of approval to the reception terminal, The connection establishment information is generated by the connection establishment information generation module, and the connection establishment information is distributedly encoded by the VSS distributed encoding module with threshold values ((total number of terminals), (total number of terminals)). Of the connection information shares of (total number of terminals), (total number of terminals −1) is provided to all the member terminals one by one, and the remaining one connection establishment information share and its original The connection establishment information which is information is managed by the database without leakage to the outside.

  Further, in the present invention of claim 36, in any of claims 32 to 35, when the member terminal receives a message indicating the connection establishment request attached with the permission information share from the new terminal. The member information terminal confirms whether the new terminal receives approval for participation / subscription from all terminals belonging to the community other than its own terminal. If the total number of terminals is two when a request for comparison is received, the two permission information shares attached to the connection establishment request message and the one permission information share managed in the database of the own terminal The VSS decryption module restores the permission information and uses the database of its own terminal. If there is no difference, the difference between the time information included in the permission information and the time information at the time of comparison is greater than or equal to a predetermined value set in advance. If there is no difference between the destination information and the new terminal, a normal response is returned to the control module, and the total number of terminals is 3 If there are more than two, the own terminal has distributed (total number of terminals− of the total number of terminals−1) × (total number of terminals−1) of the permission information shares attached to the connection establishment request message. 1) Using the one permission information share and one permission information share managed in the database of the own terminal, the permission information is restored by the VSS decoding module, and is stored in the database of the own terminal. Save Whether or not there is a difference from the permission information, and if there is no difference, whether or not the difference between the time information included in the permission information and the time information at the time of comparison is greater than or equal to the predetermined value. If it is less than the predetermined value, it is further checked whether the destination information is different from the new terminal. If there is no difference, the remaining (total number of terminals−2) × (total number of terminals−1) Whether or not the permission information share is illegal is confirmed using the permission information share verification information acquired at the time of distribution of the permission information share from the share verification module and the other member terminals. If not, a normal response is returned to the control module.

  The present invention as set forth in claim 37 further comprises permission information validity period setting means for arbitrarily setting the predetermined value indicating the validity period of the permission information.

  The present invention as described in claim 38, according to any one of claims 36 and 37, wherein the new terminal transmits a message indicating the connection establishment request to each of the member terminals, and the connection is normally established. Each of the member terminals provides the connection establishment information share stored in the database by the own terminal, and the new terminals are obtained from all the member terminals (total number of terminals −1). Including the connection establishment information share of the connection terminal, and providing the reception terminal with the connection establishment information to confirm whether the new terminal has established the connection with all the member terminals. The comparison module receives a request for comparison of the connection establishment information from the control module, and acquires it from the new terminal ( Number of terminals-1) connection establishment information share, one connection establishment information share managed in the database of its own terminal, and connection establishment information restored using the VSS decoding module Is compared with the connection establishment information managed in the database of its own terminal to check whether there is a difference. If there is no difference, the time information included in the connection establishment information is compared with It is checked whether or not the difference from the time information is equal to or larger than the predetermined value. If the difference is equal to or smaller than the predetermined value, a normal response is returned to the control module.

  Further, the present invention described in claim 39 comprises connection establishment information valid period setting means for arbitrarily setting the predetermined value indicating the validity period of the connection establishment information in claim 38.

  Further, in the present invention according to claim 40, in any one of claims 32 to 39, the receiving terminal asks each of the member terminals for approval or disapproval for participation / subscription of the new terminal to the community. The member terminal is notified as the destination information of the new terminal that wishes to invite or join / subscribe, and when the total number of terminals is three or more, the destination information of the new terminal is the VSS distributed coding The destination information share obtained by distributed encoding by the module and the destination information share verification information are notified, and each of the member terminals acquires the destination information share acquired from the reception terminal in order to obtain the original destination information. All the destinations with the destination information share verification information and the share verification module acquired from the reception terminal. By the VSS decryption module after verifying the incorrect distribution share to restore the original the destination information.

  In addition, in the present invention according to claim 41, when the member terminal submits the permission information share as an approval vote in any of claims 32 to 40, the permission information share is changed to the permission information share. The share verification module checks whether or not there is an illegality based on the verification information.

  Further, the present invention according to claim 42 is any one of claims 32 to 41, wherein, in the first stage, participation of the new terminal notified by the member terminal from all the member terminals to the community. In response to a request for approval or disapproval of the subscription, a totaling result indicating whether or not it is possible to proceed to the second stage for the voting is notified, and the voting result is notified in the second stage.

  According to the present invention, when a new entity joins or joins a community using a full mesh network, access control based on approval and disapproval votes by a plurality of entities already participating in the community can be realized and exists in the permission determination process. Allows unauthorized entities to be detected, prevents the authorization decision process from being manipulated illegally, and permits decisions when a new entity establishes a connection to each entity that has already joined or joined the community A communication system that can safely and securely perform the process, and that can reliably confirm that other entities that have joined or joined the community have agreed to (permitted) to join or join the community of the new entity, Communication methods and It is possible to provide the program.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an explanatory diagram showing a network configuration representing the relationship between terminals according to an embodiment of the present invention.

  Terminal 1, terminal 2, terminal 3, terminal 4, and public key server 5 are connected to network 100 and can communicate with each other. In the state of FIG. 1, it is assumed that no connection is established between the terminals. The public key server 5 collectively manages public keys of a plurality of terminals and is a repository that provides public keys in response to requests from the terminals.

  It is assumed that the public key server 5 manages at least the public keys of the terminal 1, the terminal 2, the terminal 3, and the terminal 4. The network 100 is an infrastructure for exchanging arbitrary information, and represents, for example, the Internet or a private network.

  FIG. 2 is a diagram showing a configuration of common function modules possessed by each of terminal 1, terminal 2, terminal 3, and terminal 4 shown in FIG.

  Here, the community is a full mesh network formed by establishing a connection to a full mesh between a plurality of terminals, and a pair of connections constructed between at least two terminals are required.

  In addition, in an event that occurs in a community, such as a new device joining / joining or leaving a device, the user wishes to invite a device that does not belong to the community and actually belongs to any device or community that invites the device. In order for a new terminal to newly join or join a certain community, an arbitrary partner terminal belonging to the community that has accessed for the first time is referred to as a reception terminal.

  A terminal that does not belong to a community and is newly invited or joined / joined is called a new terminal. Furthermore, in the community to which the service terminal belongs, a terminal that belongs to the community excluding the service terminal is called a member terminal. In the community, there is only one reception terminal, and the remaining terminals are member terminals.

  The control module 110 includes a message generation module 126, a message analysis module 128, a public key cryptosystem encryption module 121, a permission information generation module 112, a VSS distributed encoding module 116, a common key generation module 118, a connection establishment information comparison module 115, The connection establishment information generation module 114, the intention input module 111, the database 125, the public key cryptosystem decryption module 122, the VSS decryption module 117, and the share verification module 129 are provided.

  For the message generation module 126, a connection establishment request message, a connection establishment confirmation message, a community participation / subscription invitation message, a community invitation message, a community participation / subscription acceptance message, a pros and cons primary decision message, and a pros and cons final decision message Request to generate a destination information share acquisition request message, a response message, a public key acquisition request message, a voting information provision message, a primary result notification message, and a final result notification message.

  The connection establishment request message includes a request for establishing a connection when the own terminal does not belong to any community, and the other terminal does not belong to any community, and a new one that receives a community invitation message from the receiving terminal. It is generated when a terminal requests connection establishment from each member terminal, and when a new terminal that has transmitted a message indicating participation / subscription to a corresponding terminal requests connection establishment from all member terminals.

  The connection establishment confirmation message is generated as a response when the response message of the connection establishment request message is received and when the community participation / subscription acceptance message is received.

  The community participation / subscription inquiry message is generated when the responding terminal asks all member terminals about the pros and cons of joining or joining the new terminal to the community before inviting, joining, or joining the new terminal to the community.

  The community participation / subscription acceptance message is a response message of the community invitation message received by the new terminal from the reception terminal, and is generated after accepting the participation / subscription to the community and establishing connections with all the member terminals.

  The destination information share acquisition request message is generated in order to acquire the destination information share necessary for each member terminal to restore the destination information from all other member terminals.

  The primary decision message for approval or disapproval is generated as a response message after the member terminal that has received the community participation / subscription inquiry message from the receiving terminal determines whether the new terminal can participate in or join the community.

  When the total number of terminals is 3 or more, the voting information provision message is sent to all other member terminals after the primary decision is made. (Share obtained by encoding).

  The primary result notification message is prepared for voting when all the member terminals agree in the primary decision of approval / disapproval for participation / subscription of the new terminal to the community after the receiving terminal receives the primary decision message for approval / disapproval from all the member terminals. Is generated to notify all member terminals that voting is possible and voting is possible, otherwise voting is impossible.

  The final decision message of approval or disapproval is that the member terminal that sent the primary decision message of approval or disapproval receives the primary result notification message from the response terminal and returns a response message, and then the content of the primary result notification message can be voted Is generated in order to convey the intention to the receiving terminal after finally determining whether or not the new terminal can participate in or join the community.

  The final result notification message indicates whether or not all the member terminals have agreed in the final decision on the approval or disapproval for participation / subscription of the new terminal to the community after the receiving terminal receives the final approval / disapproval message from all the member terminals. It is generated in order for the receiving terminal to notify all member terminals of the absence.

  The community invitation message is generated when the receiving terminal requests a new terminal to join / subscribe.

  The response message is received at the terminal when a connection establishment request message is received, when a final decision message for approval or disapproval is received, when a destination information share acquisition request message is received, or when a voting information provision message is received Or when the primary result notification message is received, or when the final result notification message is received, when the public key acquisition request message is received for the public key server 5, it is generated as a response.

  The public key acquisition request message is generated when inquiring the public key to the external public key server 5.

  When requesting the creation of a message, the control module 110 passes a public key and a session key (common key) in the case of a connection establishment request message and a community invitation message in order to transmit the message securely, and sends an electronic message to the message to be transmitted. Request to sign and encrypt. In the case of other messages (excluding public key acquisition request messages), a session key is passed and requested to be sent after being encrypted.

  In the case of a community participation / subscription inquiry message, if the total number of terminals is 2, the destination information share of the new terminal, and if it is 3 or more, the destination information share obtained by distributedly encoding the destination information of the terminal by VSS, and the destination information share Attach destination information share verification information for verifying whether there is any fraud.

  In the case of the destination information share acquisition request message, the destination information share of the new terminal is attached.

  In the case of the primary decision message of approval or disapproval, in the case of indicating the intention of approval, when the total number of terminals is 2, the permission information share obtained by distributedly encoding the permission information with the threshold value (3, 3) by SSS, If the number of terminals is 3 or more, whether or not the permission information share obtained by distributed encoding with the threshold values ((total number of terminals), (total number of terminals)) by VSS and whether the permission information share is correctly generated without fraud Attach permission information share verification information for confirmation.

  In the case of the voting information provision message, the permission information share obtained by distributedly encoding the permission information with the threshold values ((total number of terminals), (total number of terminals)) by VSS and the permission information share verification information are attached.

  In the case of the final decision message of approval or disapproval, if the member terminal indicates the approval intention, the permission ticket (when the total number of terminals is 2, the permission information share generated by the own terminal and the destination information of the own terminal are all If the number of terminals is 3 or more, agree with the (permitted number of terminals-2) permission information shares and destination information of the own terminal encrypted with the public key of the new terminal) obtained from all other member terminals Attach as a vote.

  In the case of a community invitation message, (new terminal number-1) × (total terminal number-1) permission tickets necessary for a new terminal to establish a connection with all member terminals are attached.

  In the case of a connection establishment request message, when a new terminal transmits to each member terminal, if all terminals are 2, two permission information shares are used. If more than three, (number of all terminals-1) × (all The number of terminals-1) permission information share is attached. Nothing is attached when both the own terminal and the partner terminal have not joined or joined the community.

  In the case of the community participation / subscription acceptance message, the new terminal attaches (total number of terminals minus 1) connection establishment information shares acquired when connections are established with all member terminals.

  In the case of the final result notification message, the receiving terminal attaches one connection establishment information share.

  For the message analysis module 128, the control module 110 receives a public key necessary for decrypting a connection establishment request message or a community invitation message that has been digitally signed and encrypted from among the received messages. If not, a public key acquisition request is transmitted. After acquiring the public key, the control module 110 passes the acquired public key to the message analysis module 128.

  The public key cryptosystem encryption module 121 is requested to provide the public key and encrypt the permission information share including the destination information of the distribution source terminal of the permission information share.

  The permission information generation module 112 is requested to generate permission information.

  The VSS distributed encoding module 116 is requested to perform distributed encoding of various types of information (terminal destination information, permission information, connection establishment information) using the VSS.

  The common key generation module 118 is requested to generate a session key (common key) that is required when the message is digitally signed or encrypted in order to prevent message spoofing, falsification, and eavesdropping.

  The connection establishment information comparison module 115 is requested to compare the connection establishment information. The request is generated when the community participation / subscription acceptance message is received, and the connection establishment information share included in the message is provided to the connection establishment information comparison module 115.

  The connection establishment information generation module 114 is requested to generate connection establishment information. The request is that after the receiving terminal receives a final decision message for approval or disapproval from all the member terminals, if all the member terminals are in favor of joining or joining the new terminal community, a final result notification message is sent to each member terminal. Occurs before sending to.

  For the intention input module 111, various decisions (determination of whether or not to establish a connection, primary determination of approval / disapproval for participation / subscription of a new terminal to the community, and participation / subscription of a new terminal to the community Request final decision on approval or disapproval, decision on community participation or participation).

  The database 125 is inquired and stored for various information.

  The public key cryptosystem decryption module 122 is requested to decrypt the permission information share (permission ticket) encrypted with the public key of the terminal itself. The request is generated when the new terminal receives a community invitation message.

  The VSS decoding module 117 is requested to decode the distributedly encoded destination information share when all terminals are 3 or more.

  The share verification module 129 is requested to check whether the permission information share attached to the received message or the destination information share is fraudulent.

  The intention input module 111 has an interface with the control module 110. Since there is an inquiry from the control module 110 as to whether a connection may be established, whether a new terminal may be added to the community, or whether to join / join the community (YES or NO) )) To the control module 110.

  The permission information generation module 112 has a control module 110, a database 125, and an interface.

  When requested to generate permission information from the control module 110, the permission information generation module 112 generates permission information, stores it in the database 125, and returns the generated permission information to the control module 110. This permission information is necessary when newly inviting, joining, or joining a terminal to a community formed by establishing a full mesh connection between multiple terminals. Generation of destination information and permission information for the new terminal It is composed of time information and arbitrary random keywords.

  The permission information comparison module 113 has an interface with the control module 110, the VSS decryption module 117, and the database 125.

  The control module 110 is requested to compare permission information. The request is generated when each member terminal receives a connection establishment request message from the new terminal. At this time, when the total number of terminals is 2, two permission information shares are provided from the control module 110, and the VSS decoding is performed by combining these permission information shares and the permission information shares stored in the database 125 of the own terminal. Requesting the decryption module 117 to decrypt the permission information, compare the decrypted permission information with the permission information stored in the database 125, and check whether there is a difference. If there is no difference, the permission information The difference between the time information included in the time information and the time information at the time of comparison is less than or equal to a certain value, and if it is less than or equal to the certain value, the terminal destination information included in the permission information and the terminal that transmitted the connection establishment request message Compare whether the destination information is correct.

  The constant value is an arbitrary value set in advance, and is input and set by a permission information valid period setting unit (not shown).

  In addition, when the total number of terminals is 3 or more, the number of (total number of terminals minus 1) distributed by the own terminal among (total number of terminals minus 1) × (total number of terminals minus 1) attached to the message. Information share is provided from the control module 110, and the permission information share and the permission information share stored in the database 125 of the own terminal are combined, and the VSS decryption module 117 is requested to decrypt the permission information. The decrypted permission information is compared with the permission information stored in the database 125 to check whether there is a difference. If there is no difference, the difference between the time information included in the permission information and the time information at the time of comparison is constant. If it is less than a certain value, the ratio of whether the destination information included in the permission information matches the destination information of the terminal that sent the connection establishment request message. To.

  When the above comparison is completed, a normal response is returned to the control module 110.

  The connection establishment information generation module 114 has an interface with the control module 110.

  The control module 110 receives a request for generating connection establishment information, and composes and generates the destination information of the new terminal, the time information when the connection establishment information is generated, and an arbitrary random keyword. Then, the information is returned to the control module 110.

  The connection establishment information comparison module 115 has an interface with the control module 110, the database 125, and the VSS decryption module 117.

  The control module 110 is requested to compare the connection establishment information. The request is generated when a community participation / subscription acceptance message is received.

  When the connection establishment information comparison module 115 is provided with the connection establishment information share (total number of terminals −1) included in the community participation / subscription acceptance message from the control module 110, the connection establishment information comparison module 115 stores the connection establishment information share in the database 125. The connection establishment information is restored via the VSS decryption module 117 from the established connection establishment information share.

  The restored connection establishment information is compared with the connection establishment information stored in the database 125. At this time, it is compared whether there is any difference between these pieces of information. If there is no difference, it is confirmed whether the difference between the time information included in the connection establishment information and the current time information is a certain value or less.

  The constant value is an arbitrary value set in advance, and is input and set by a connection establishment information valid period setting unit (not shown).

  When the above comparison is completed, a normal response is returned to the control module 110.

  The VSS distributed encoding module 116 has an interface with the control module 110 and the database 125.

  Various kinds of information are provided to the control module 110, and distributed coding by VSS or SSS is requested.

  In the case of terminal destination information, distributed coding is performed with VSS ((total number of terminals-1), (total number of terminals-1)) by VSS, and (total number of terminals-1) destination information shares are generated. Further, destination information share verification information for verifying the destination information share is generated.

  In the case of permission information, when the total number of terminals is 2, by SSS, distributed coding is performed with thresholds (3, 3), three permission information shares are generated, two are stored in the database 125, and the remaining one is stored. Return to the control module 110.

  Further, when the total number of terminals is 3 or more, distributed coding is performed with the threshold values ((total number of terminals), (total number of terminals)) by VSS to generate (total number of terminals) permission information shares. In addition, permission information share verification information for verifying permission information share is generated. Then, after storing one permission information share (total number of terminals) in the database 125, the remaining permission information share and permission information share verification information are returned to the control module 110.

  In the case of connection establishment information, distributed encoding is performed using thresholds ((total number of terminals), (total number of terminals)) based on SSS, and (total number of terminals) connection establishment information shares are generated. Then, one of the obtained connection establishment information shares is stored in the database 125 and the rest is returned to the control module 110.

  The VSS decryption module 117 has an interface with the control module 110, the connection establishment information comparison module 115, and the permission information comparison module 113.

  The VSS decryption module 117 restores the original information from the plurality of shares using the VSS or SSS threshold method.

  The control module 110 is requested to restore the destination information from the destination information share.

  The connection establishment information comparison module 115 is requested to restore the connection establishment information from the connection establishment information share.

  The permission information comparison module 113 is requested to restore permission information from the permission information share.

  The common key generation module 118 has an interface with the control module 110 and the database 125.

  The control module 110 is requested to generate a session key. The common key generation module 118 generates a common key encryption session key, stores it in the database 125, and returns it to the control module 110.

  The common key encryption module 119 has an interface with the message generation module 126.

  Since the message generation module 126 is requested to encrypt using the session key, the common key encryption system encryption module 119 performs encryption using the common key encryption system.

  The common key cryptosystem decryption module 120 has an interface with a message analysis module 128 and a database 125.

  The message analysis module 128 is requested to decrypt the received message. When the request is received, the session key shared with the message transmission source terminal is inquired of the database 125, and after being obtained, decryption is performed using the session key.

  The public key cryptosystem encryption module 121 has an interface with the control module 110 and the message generation module 126.

  For the control module 110, the permission information share, which is information attached when transmitting the community invitation message or the final decision message of approval or disapproval, is encrypted with the public key of the new terminal, including the destination information of the own terminal Be asked to do.

  For the message generation module 126, in the digital signature and encryption performed when creating the connection establishment information message and the community invitation message, the encryption of the digest with the secret key and the encryption of the session key with the public key are performed. Requested.

  The public key cryptosystem decryption module 122 has an interface with a control module 110, a message analysis module 128, and a database 125.

  When the message analysis module 128 receives the connection establishment request message and the community invitation message, the message analysis module 128 is requested to decrypt the electronic signature and the encrypted message.

  The control module 110 is requested to decrypt the permission information share (encrypted permission information share) for the purpose of decryption.

  The digest generation module 123 has an interface with a message generation module 126 and a message analysis module 128.

  The digest generation module 123 generates a digest by using a hash function (message digest function) for the purpose of preventing falsification of a message to be transmitted and for the purpose of confirming whether the received message has been falsified. .

  The message fraud determination module 124 has an interface with the message analysis module 128.

  When the terminal receives a digitally signed and encrypted message (connection establishment request message, community invitation message) and decrypts the message, the message fraud determination module 124 sends a message fraud message from the message analysis module 128. You are asked to check if there is any. At this time, since the decrypted digest and the generated digest are passed from the message analysis module 128, it is confirmed whether or not there is a difference between these two digests. If there is no difference, a normal response is sent to the message analysis module 128. Return to.

  The database 125 includes a control module 110, a common key cryptosystem decryption module 120, a public key cryptosystem decryption module 122, a permission information comparison module 113, a connection establishment information comparison module 115, a permission information generation module 112, and a VSS distributed coding module 116. And an interface with the common key generation module 118.

  The database 125 includes a private key of the own terminal, a public key, a session key, permission information, permission information share, permission information share verification information, terminal destination information, destination information share, destination information share verification information, connection establishment information, connection Manages establishment information sharing and a list of devices participating and participating in the community.

  The database 125 provides information required from each module, and conversely stores it.

  The message generation module 126 has an interface with the control module 110, digest generation module 123, public key encryption module 121, common key encryption module 119, and message processing module 127.

  For the control module 110, a connection establishment request message, a connection establishment confirmation message, a community participation / subscription invitation message, a community invitation message, a community participation / subscription acceptance message, a primary decision message for approval / disapproval, a final decision message for approval / disapproval, A request is made to create a destination information share acquisition request message, response message, public key acquisition request message, voting information provision message, primary result notification message, and final result notification message.

  The message processing module 127 has an interface with the message generation module 126, the message analysis module 128, the external terminals 2 to 4, and the public key server 5.

  The message generation module 126 is requested to transmit the created message to the terminals 2 to 4 and the public key server 5 connected to the network 100.

  The message analysis module 128 is requested to perform analysis processing on the messages received from the terminals 2 to 4 and the public key server 5.

  The message analysis module 128 has an interface with the control module 110, digest generation module 123, message processing module 127, message fraud determination module 124, common key cryptosystem decryption module 120, and public key cryptosystem decryption module 122.

  From the message processing module 127, a connection establishment request message, a connection establishment confirmation message, a community participation / subscription inquiry message, a community invitation message, a community participation / subscription acceptance message, a primary decision message for approval / disapproval, a final decision message for approval / disapproval, and destination information Various messages such as a share acquisition request message, a response message, a public key acquisition request message, a voting information provision message, a primary result notification message, and a final result notification message are passed.

  When a connection establishment request message and a community invitation message are passed, since these messages are digitally signed and encrypted, the public key cryptosystem decryption module 122, the common key cryptosystem decryption module 120, and the digest generation module 123, the message fraud determination module 124 is used to decrypt the message, check for impersonation and tampering, and if there is no fraud, the content of the decrypted message and the attached information are passed to the control module 110. At this time, if the internal database 125 does not have the public key necessary for decrypting the message, the public key is acquired through the control module 110.

  Since the other messages are encrypted with the session key, the common key cryptosystem decryption module 120 is used to perform decryption using the session key shared with the message source terminal, The contents of the decrypted message and the attached information are passed to the control module 110.

  The share verification module 129 has an interface with the control module 110, and share verification information (specifically, each share (destination information share, permission information share) obtained by distributed coding using VSS is obtained from another terminal. Is checked for fraud by using destination information share verification information and permission information share verification information).

  A terminal 7 is an arbitrary terminal among the terminal 1, the terminal 2, the terminal 3, and the terminal 4 of FIG.

  FIG. 3 is an explanatory diagram showing messages exchanged between the terminal 1 and the terminal 2 when a community of the minimum scale is formed from the initial state where no connection of FIG. 1 is established. In FIG. 3, it is assumed that the terminal 1 knows the destination information for transmitting a message to the terminal 2 in advance.

  The terminal 1 needs the public key of the terminal 2 in order to establish a secure connection with the terminal 2. The terminal 1 transmits a public key acquisition request message 300 to the public key server 5. When the public key server 5 receives the public key acquisition request message 300, the public key server 5 determines the content of the message and returns a response message 301 with the public key of the terminal 2 attached thereto.

  Next, the terminal 1 transmits a connection establishment request message 302 to the terminal 2. The terminal 2 receives the connection establishment request message 302 from the terminal 1. However, since the message 302 transmitted from the terminal 1 has been digitally signed and encrypted, the message is first decrypted. Here, the public key of the terminal 1 is required. If the public key of the terminal 1 is not stored in the internal database, the public key server 5 is inquired of the public key of the terminal 1 by the public key acquisition request message 303. The public key server 5 returns a response message 304 attached with the public key of the terminal 1.

  When the terminal 2 obtains the public key of the terminal 1, the terminal 2 decrypts the connection establishment request message 302 using the public key, and knows that the terminal 1 has an intention to establish a connection. The terminal 2 determines whether or not to establish a connection by the intention input module of FIG. 2, and a response message 305 reflecting the intention is returned to the terminal 1. Here, it is assumed that the terminal 2 accepts the connection establishment request of the terminal 1.

  The terminal 1 knows from the response message 305 that a connection can be established. Then, a connection establishment confirmation message 306 is returned to the terminal 2 to establish a connection.

  FIG. 4 is a sequence diagram illustrating module processing in the terminal 1 until the terminal 1 acquires the public key of the terminal 2 in FIG. 3, transmits a connection establishment request message 302 to the terminal 2, and establishes a connection.

  In FIG. 3, assume that terminal 1 wants to establish a connection with terminal 2. Further, it is assumed that the terminal 1 knows the destination information of the terminal 2 in advance. The control module of the terminal 1 is notified from the intention input module that it wants to establish a connection with the terminal 2.

  The control module of the terminal 1 transmits a connection establishment request message to the terminal 2, but performs electronic signature and encryption of the message in order to establish the connection securely. The control module inquires of the public key of the terminal 2 in the database (sequences 1000 and 1001), and if it does not have the public key of the terminal 2, inquires of the public key server 5 about the public key of the terminal 2 (sequence 1002 to 1002). 1007). When the public key is acquired, it is stored in the database (sequence 1008, 1009).

  The control module requests the common key generation module to generate a session key used for message exchange after establishing a connection with the terminal 2 (sequence 1010). Then, after the connection is established, the generated session key is stored in a database for use in message encryption (sequence 1011 and sequence 1012). Then, the common key generation module returns the generated session key to the control module (sequence 1013).

  The control module requests the message generation module to generate a connection establishment request message with an electronic signature and encryption (sequence 1014). At this time, the control module provides the message generation module with the session key shared with the terminal 2 and the public key of the terminal 1.

  The message generation module generates a message describing the contents of the connection establishment request, and requests the digest generation module to generate a digest of the message (sequences 1015 and 1016).

  When the digest is obtained, the control module uses the private key of the terminal 1 and encrypts it with the public key cryptosystem via the public key cryptosystem encryption module (sequences 1017 and 1018).

  Then, the contents including both the contents of the connection establishment request and the encrypted digest are encrypted by the common key encryption method using the session key (sequences 1019 and 1020). This is information A. The session key is encrypted by the public key cryptosystem with the public key of the terminal 2 (sequence 1021, 1022). This is information B. Then, the information A and the information B are combined and transmitted as a connection establishment request message through the message processing module (sequence 1023) to the terminal 2 (sequence 1024).

  Hereinafter, a process (sequence 1015 to 1022) for performing electronic signature and encryption on a message is referred to as a message electronic signature / encryption process.

  Terminal 1 waits for a response from terminal 2. When the message processing module of the terminal 1 receives the response message 305 (sequence 1025), the message is encrypted with the session key shared with the terminal 2 (generated in sequences 1017 and 1018). Through the analysis module (sequence 1026), message decryption processing is performed (sequences 1027 to 1030).

  Hereinafter, the message decryption process (sequence 1027 to 1030) using the session key is referred to as a message decryption process.

  The message analysis module decrypts the message and then passes the decrypted message to the control module.

  The control module knows that the connection can be established from the content of the decrypted message. Then, the control module transmits a connection establishment confirmation message, but since the session key has already passed to the terminal 2, the message is encrypted and transmitted by the common key encryption method using the session key (sequences 1032 to 1036).

  Hereinafter, the message encryption process using the session key (sequence 1033, 1034) is referred to as a message encryption process.

  4, sequences 1004 and 1005 correspond to messages 300 and 301 in FIG. 3, sequence 1025 corresponds to message 305 in FIG. 3, and sequence 1036 corresponds to message 306 in FIG.

  FIG. 5 is a sequence diagram showing module processing when the terminal 2 receives the connection establishment request message 305 transmitted from the terminal 1 in the sequence 1025 of FIG.

  When the message processing module of the terminal 2 receives the message 302, since the electronic signature and encryption are performed, the message is decrypted.

  First, in order to obtain a session key from the information B among the information A and information B included in the message 302, the session key is obtained by decryption by the public key cryptosystem using the secret key of the terminal 2. (Sequence 1101 to 1105).

  Next, using the obtained session key, information A is decrypted by a common key cryptosystem (sequences 1106 and 1107). The obtained information includes the content of the connection establishment request and the digest encrypted with the secret key of the terminal 1. In order to obtain the digest from the encrypted digest, decryption is performed using the public key of the terminal 1 (sequences 1108 to 1111). At this time, if the database of the terminal 2 does not have the public key of the terminal 1, the message analysis module once requests the control module to acquire the public key of the terminal 1 (sequence 1112).

  The control module requests the public key of the terminal 1 from the public key server 5 (sequences 1113 to 1118). After the acquisition, the control module stores the public key of the terminal 1 in the database (sequence 1119, 1120). The control module passes the acquired public key of the terminal 1 to the message analysis module (sequence 1121).

  The message analysis module uses the public key to decrypt the encrypted digest (sequences 1122 and 1123). This is called digest C.

  After digest decoding, the message analysis module generates a digest from the content of the obtained connection establishment request in order to confirm whether or not the content of the connection establishment request has been tampered (sequence 1124, 1125). This is called digest D. Then, digest C and D are compared, and a message fraud determination module is requested to check for fraud (sequence 1126).

  The message fraud determination module checks the difference between digests C and D, and returns a normal response if there is no difference (sequence 1127).

  When the message analysis module receives a normal response, it passes the content of the connection establishment request and the session key to the control module (sequence 1128).

  Hereinafter, the decryption process (sequence 1102 to 1127) of the electronic signature and the encrypted message is referred to as a message decryption process.

  The control module knows from the content of the connection establishment request that the terminal 1 wants to establish a connection with the terminal 2. The control module requests the intention input module to make a decision on connection establishment (sequence 1129). Here, it is assumed that the terminal 2 has an intention to establish a connection. The intention input module notifies the control module that there is an intention to establish a connection (sequence 1130).

  The control module stores the session key in the database for secure message exchange after the connection is established (sequences 1131 and 1132).

  In order to return a response message, the control module asks the message generation module to create a message indicating the content of acceptance of connection establishment (sequence 1133). At this time, the control module provides the session key to the message generation module.

  The message generation module generates a message indicating the content of acceptance of connection establishment, further performs a message encryption process, and transmits a response message 305 through the message processing module (sequences 1134 to 1137).

  After transmitting the response message 305, when the message processing module of the terminal 2 receives a connection establishment confirmation message from the terminal 1 (sequence 1138), the message is encrypted with the session key shared with the terminal 1, so that the message decryption is performed. The message analysis module passes the decrypted message to the control module (sequences 1139 to 1144).

  The control module knows that the connection has been established from the content of the decrypted message.

  Through the above process, a connection is established between the terminal 1 and the terminal 2.

  5, the sequence 1100 corresponds to the message 302 in FIG. 3, the sequence 1137 corresponds to the message 305 in FIG. 3, and the sequence 1138 corresponds to the message 306 in FIG.

[First Embodiment]
In FIG. 6, since the connection 10 has already been established between the terminal 1 and the terminal 2, and the community 200 of the smallest scale with the total number of terminals 2 is formed between the terminal 1 and the terminal 2, the community 200 side newly It is explanatory drawing which shows the message exchanged between terminals required in order to invite the terminal 3 to the community 200 as a terminal.

  In FIG. 6, it is assumed that the terminal that wants to invite the terminal 3 to the community 200 is the terminal 1 (that is, the terminal 1 is the receiving terminal, the terminal 3 is the new terminal, and the member terminal is the terminal 2). The terminal 1 first inquires whether the internal database has a public key necessary for establishing a secure connection with the terminal 3, and if not, makes an acquisition request to the external public key server 5 (message 400). 401). Then, a community participation / subscription inquiry message 402 indicating the contents of the invitation request is transmitted to the terminal 2. At this time, the destination information of the terminal 3 is included in the message.

  When the terminal 2 receives the community participation / subscription inquiry message 402, the terminal 2 knows that the terminal 1 wishes to invite the terminal 3 to the community.

  The terminal 2 inquires of the internal database whether or not it has a public key necessary for establishing a secure connection with the terminal 3, and if not, makes an acquisition request to the public key server 5 (message 403, Message 404). Then, after obtaining the public key, the terminal 2 makes a primary determination as to whether or not to allow the terminal 3 to participate in or join the community 200. Here, it is assumed that the terminal 2 agrees.

  The terminal 2 generates permission information (1-2), which is distributedly encoded with threshold values (3, 3), and permits information share (1-2-1), permission information share (1-2-2), permission An information share (1-2-3) is generated.

  Of the permission information (1-2) and the three permission information shares, two permission information shares (here, permission information share (1-2-2) and permission information share (1-2-3)) The purpose of confirming whether or not the terminal 3 has gained the approval of all the terminals participating in or joining the community with respect to the participation or participation in the community 200 when the terminal 2 itself receives a connection establishment request for the terminal 3 And stored in an internal database for use as voting information for the terminal itself.

  The terminal 2 transmits, to the terminal 1, a primary decision message 405 for pros and cons attached with a permission information share (1-2-1) as voting information as a response message to the community participation / subscription inquiry message 402. In order for the terminal 3 to participate in or join the community, it is necessary to acquire permission information shares from all terminals at the time of final decision on approval or disapproval.

  The terminal 1 receives the approval / disapproval primary decision-making message 405, confirms that the terminal 2 is in favor of joining / subscribing to the community 200 of the terminal 3 based on the message content, and allows permission information sharing (1-2-1 ) In the internal database.

  Since the terminal 1 has received the primary decision message for approval / disapproval from all the member terminals (terminal 2), the terminal 1 transmits a primary result notification message to all the member terminals. At this time, if all the member terminals indicate approval, it is notified that voting is possible, and otherwise, it is notified that voting is impossible.

  The terminal 1 transmits to the terminal 2 a primary result notification message 406 indicating that voting is possible.

  The terminal 2 receives the primary result notification message 406 from the terminal 1, and all the member terminals agree to participate / subscribe to the community 200 of the terminal 3 in the primary decision message of approval or disapproval and know that voting is possible. Then, the response message 407 is transmitted to the terminal 1.

  Next, the terminal 2 makes a final decision as to whether or not the terminal 3 participates in or joins the community 200. Here, it is assumed that the terminal 2 finally agrees to the participation / subscription of the terminal 3 to the community 200. The terminal 2 generates the permission ticket (1-2) encrypted with the public key of the terminal 3 by combining the destination information of the terminal 2 and the permission information share (1-2-3).

  The terminal 2 finally attaches a permission ticket (1-2) to the content indicating that the terminal 3 agrees to participate / subscribe to the community 200, and transmits a final decision message 408 of approval or disapproval. After transmitting the message 408, the terminal 2 receives the response message 409 from the terminal 1.

  On the other hand, the terminal 1 confirms that the terminal 2 finally agrees to the participation / subscription of the terminal 3 to the community 200 based on the final decision message 408 of approval / disapproval, and stores the permission ticket (1-2) inside. Save to the database. Then, a response message 409 is transmitted to the terminal 2.

  The terminal 1 receives the final decision message for approval / disapproval from all the member terminals and knows that all the member terminals agree.

  The terminal 1 generates connection establishment information (1-1) and stores it in the database. Then, the connection establishment information (1-1) is distributedly encoded by the threshold value (2, 2) by VSS, and the generated connection establishment information share (1-1-1) and connection establishment information share (1-1-2) One of them (here, connection establishment information share (1-1-1)) is stored in the database.

  The terminal 1 transmits to the terminal 2 a final result notification message 410 in which the connection establishment information share (1-1-2) is attached to the content informing that all the member terminals agree. Then, the response message 411 is received from the terminal 2.

  The terminal 2 receives the final result notification message 410 and knows that all the member terminals have finally agreed to the participation / subscription of the terminal 3 to the community 200. Also, the connection establishment information share (1-1-2) is acquired. Then, a response message 411 is transmitted to the terminal 1.

  On the other hand, after the terminal 1 receives the response message 411, the terminal 1 includes the destination information of the terminal itself in the permission information share (1-2-1) acquired from the primary decision message 405 for approval and disapproval, and uses the public key of the terminal 3 Encryption is performed (referred to as permission ticket (1-3)), and a community invitation message 412 attached with permission ticket (1-2) and permission ticket (1-3) is transmitted to terminal 3. At this time, the message is digitally signed and encrypted.

  Terminal 3 receives community invitation message 412 and decrypts the message. Here, the public key of the terminal 1 is required, but if it is not stored in the database, an acquisition request is made to the external public key server 5 (messages 413 and 414). The terminal 1 knows from the decrypted message content that it wishes to invite the terminal 3 to the community. At this time, a permission ticket (1-2) and a permission ticket (1-3) are acquired.

  The terminal 3 decrypts the permission ticket (1-2) and the permission ticket (1-3) with the secret key in order to check what terminal is participating in or joining the community 200, and the permission information share obtained From (1-2-1), permission information share (1-2-3), and destination information of the terminal 1 and the terminal 2, it is known that the terminal 1 and the terminal 2 are participating in / joining the community 200.

  It is assumed that the terminal 3 is in favor of the community 200 invitation. The terminal 3 inquires of the terminal 2 about the public key of the terminal 2 in order to establish a secure connection with the terminal 2, and if not, makes an acquisition request to the external public key server 5 (message 415, response message) 416).

  The terminal 3 transmits a connection establishment request message 417 including the permission information share (1-2-1) and the permission information share (1-2-3) to the terminal 2.

  When the terminal 2 receives the connection establishment request message 417 from the terminal 3, the terminal 3 sends it to the community 200 using the attached permission information share (1-2-1) and permission information share (1-2-3). Check whether all other terminals have agreed to participate / subscribe.

  First, using the permission information share (1-2-2), the acquired permission information share (1-2-1), and permission information share (1-2-3) that the terminal 2 has in the database , Decryption is performed by VSS, and permission information (1-2-A) is generated. Then, the permission information (1-2) and permission information (1-2-A) held in the internal database of the terminal 2 are compared to confirm whether there is a difference. If there is a difference, the access of the terminal 3 is regarded as illegal (that is, it is not approved by all other terminals in the community), and the connection is not established. If there is no difference, the difference between the time information at the time of comparison and the time information included in the permission information is calculated. If the value is equal to or longer than a certain time, it is determined to be illegal and the connection is not established. If there is no illegality, the destination information described in the permission information is compared with the destination information of the terminal 3, and if there is a difference, the connection is not established.

  When the above checks are performed and it is confirmed that the terminal 3 is not fraudulent and that all other terminals have agreed to participate in or join the community 200, the terminal 2 has a connection established in its internal database. A response message 418 attached with the information share (1-1-2) is transmitted to the terminal 3.

  After transmitting the response message 418, the terminal 2 receives a connection establishment confirmation message 419 from the terminal 3.

  On the other hand, when the terminal 3 receives the response message 418, the terminal 3 stores the connection establishment information share (1-1-2) in the internal database, and then transmits a connection establishment confirmation message 419 to the terminal 2.

  After establishing the connection with the terminal 2, the terminal 3 transmits a community participation / subscription acceptance message 420 attached with the connection establishment information share (1-1-2) as a response message of the community invitation message 412.

  The terminal 1 receives the community participation / subscription acceptance message 420 from the terminal 3, and acquires the connection establishment information share (1-1-2). Then, in order to confirm whether the terminal 3 has established connections with all other terminals in the community, the connection establishment information share (1-1-2) and the connection establishment information share (1-1) held in the internal database -1), the connection establishment information is decrypted to generate connection establishment information (1-1-A).

  The obtained connection establishment information (1-1-A) is compared with the connection establishment information (1-1) held in the internal database to check whether there is any difference.

  If there is a difference, it is determined that the connection has not been established with all the other terminals that the terminal 3 has joined / subscribed to the community 200, and the connection is not established. If there is no difference, it is checked whether or not the difference between the time information included in the connection establishment information and the time information at the time of comparison is within a certain time. If it is longer than a certain time, the connection is not established.

  When the above check is completed, the terminal 1 finally transmits a connection establishment confirmation message 421 to the terminal 3 to establish a connection with the terminal 3.

  As described above, by exchanging messages 400 to 421 among terminal 1, terminal 2, terminal 3, and public key server 5, terminal 3 is newly invited to community 200.

  7 to 20 are sequence diagrams showing in detail a process in which each terminal processes a message exchanged between the terminals in FIG. 6 using an internal module.

  FIG. 7 is a sequence diagram showing module processing until the terminal 1 transmits to the terminal 2 a message (community participation / subscription inquiry message) indicating the contents of the terminal 3 asking for approval or disapproval regarding the invitation of the terminal 3.

  The control module of the terminal 1 inquires of the database to acquire the destination information of the terminal 3, the session key shared with the terminal 2, and the public key of the terminal 3 (sequences 1200 and 1201). At this time, if the public key of the terminal 2 is not in the database, the external public key server 5 is inquired (sequence 1202 to 1207) and stored in the database (sequence 1208 and 1209).

  The control module requests the message generation module to generate a community participation / subscription inquiry message and transmit it to the terminal 2 (sequence 1210). At this time, the destination information of the terminal 3 and the session key are passed at the same time.

  The message generation module generates a message in which the destination information of the terminal 3 is attached to the content asking whether to accept or reject the invitation of the terminal 3 to the community 200, performs the message encryption process, and then sends the community participation / subscription inquiry message 402 to the terminal 2. (Sequences 1211 to 1214).

  In FIG. 7, sequences 1204, 1205, and 1214 correspond to the messages 400, 401, and 402 in FIG.

  FIG. 8 is a sequence diagram showing module processing in the terminal 2 when the terminal 2 receives the community participation / subscription inquiry message 402 transmitted by the terminal 1 in FIG.

  When the message processing module of the terminal 2 receives the message 402, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 1 (sequence 1300 to 1300). 1305). Then, the decrypted message is passed to the control module (sequence 1306).

  The control module knows from the message that terminal 1 wants to invite terminal 3 to community 200.

  The control module checks whether or not it has the public key of the terminal 3 (sequences 1307 and 1308), and if not, makes an acquisition request to the public key server 5 (sequences 1309 to 1314). Then, after acquisition, it is stored in the database together with the destination information of the terminal 3 (sequences 1315 and 1316).

  Then, the control module asks the intention input module whether or not the terminal 3 participates or joins the community 200 (sequence 1317). Here, it is assumed that there is a will of approval. The intention input module informs the control module that there is an intention of approval (sequence 1318). Decision making at this point is primary.

  The control module requests the permission information generation module to generate permission information (sequence 1319).

  The permission information generation module generates permission information (1-2), stores it in the database (sequence 1320, 1321), and returns the permission information (1-2) to the control module (sequence 1322).

  In order to generate the voting information, the control module requests the VSS distributed encoding module to perform the distributed encoding of the permission information (1-2) (sequence 1323).

  Since the total number of terminals in the VSS distributed coding module is 2, the permission information (1-2) is distributedly encoded with the thresholds (3, 3), the permission information share (1-2-1), and the permission information share (1- 2-2) and permission information share (1-2-3). Then, two of the permission information shares (here, permission information share (1-2-2) and permission information share (1-2-3)) are stored in the database (sequences 1324 and 1325), and permission is granted. Information sharing (1-2-1) is returned to the control module (sequence 1326).

  The control module inquires of the database about the session key shared with the terminal 1 (sequences 1327 and 1328), and sends the approval / disapproval primary decision message with the permission information share (1-2-1) to the terminal 1. The message generation module is requested (sequence 1329). At this time, the session key and permission information share (1-2-1) are simultaneously passed to the message generation module.

  The message generation module generates a message with permission information share (1-2-1) attached to the content of approval, performs a message encryption process, and transmits the message to the terminal 1 via the message processing module (sequence 1330). ~ 1333).

  In FIG. 8, sequences 1300, 1311, 1312, and 1333 correspond to the messages 402, 403, 404, and 405 in FIG.

  FIG. 9 is a sequence diagram showing processing between modules when the terminal 1 receives the primary decision message 405 for approval / disapproval transmitted from the terminal 2 in FIG.

  When the message processing module of the terminal 1 receives the message 405, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 2 (sequence 1400 to 1400). 1405). Then, the decrypted message content and the attached permission information share (1-2-1) are passed to the control module (sequence 1406).

  The control module knows from the decrypted message content that the terminal 2 is willing to agree. And the permission information share (1-2-1) which is the acquired information for voting is preserve | saved in a database (sequence 1407, 1408).

  Since the terminal 1 has received the primary decision message for approval / disapproval from all the member terminals (terminal 2), the terminal 1 transmits a primary result notification message to all the member terminals. At this time, if all the member terminals indicate approval, it is notified that voting is possible, and otherwise, it is notified that voting is impossible.

  The control module of the terminal 1 requests the message generation module to transmit a primary result notification message indicating that voting is possible to all member terminals (sequence 1409).

  The message generation module generates a message indicating that voting is possible, performs a message encryption process, and transmits a primary result notification message 406 to the terminal 2 via the message processing module (sequences 1410 to 1413). .

  After transmitting the primary result notification message 406, the control module of the terminal 1 transmits a response message 407 from the terminal 2 (sequences 1414 to 1420).

  In FIG. 9, sequences 1400, 1413, and 1414 correspond to the messages 405, 406, and 407 in FIG. 6, respectively.

  FIG. 11 is a sequence diagram showing module processing in the terminal 2 when the terminal 2 receives the primary result notification message 406 in FIG. 10.

  Upon receiving the message 406, the message processing module of the terminal 2 performs a message decryption process via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 1 (sequence 1500). ~ 1505). Then, the decrypted message is passed to the control module (sequence 1506).

  The control module obtains approval from all the member terminals (terminal 2) in the primary decision message of approval / disapproval received from all the member terminals by the terminal 1, and knows that the voting preparation is completed and voting is possible. .

  The control module transmits a response message 407 of the primary result notification message 406 to the terminal 1 through the message generation module (sequences 1507 to 1511).

  In FIG. 10, sequences 1500 and 1511 correspond to the messages 406 and 407 in FIG. 6, respectively.

  FIG. 11 is a sequence diagram showing module processing in the terminal 2 after transmitting the response message 407 to the terminal 1 in FIG.

  The control module of the terminal 2 inquires the intention input module about the final decision of approval or disapproval for the participation / subscription of the terminal 3 in the community 200 (sequence 1600). Here, it is assumed that the terminal 2 finally agrees to the participation / subscription of the terminal 3 to the community 200. The intention input module communicates the intention indicating approval to the control module (sequence 1601).

  When the intention of approval is transmitted to the control module, the database is inquired about the session key shared with the terminal 1, the public key of the terminal 3, and the permission information share (1-2-3) (sequences 1602, 1603). Then, it requests to encrypt the permission information share (1-2-3) and the destination information of the own terminal together with the public key of the terminal 3 (sequences 1604 and 1605). Thereby, the permission ticket (1-2) is generated.

  The control module provides the permission ticket (1-2) and the session key shared with the terminal 1 to the message generation module, and requests the terminal 1 to transmit a final decision message for approval or disapproval (sequence 1606). ).

  The message generation module generates a message with the approval ticket (1-2) attached to the final approval intention content, performs a message encryption process, and transmits a final approval / disapproval message 408 of approval / disapproval through the message processing module (sequence) 1607-1610).

  The terminal 2 transmits a final decision message 408 for approval / disapproval to the terminal 1 and then receives a response message 409 from the terminal 1 (sequences 1611 to 1617).

  In FIG. 11, sequences 1610 and 1611 correspond to the messages 408 and 409 in FIG. 6, respectively.

  FIG. 12 is a sequence diagram illustrating module processing in the terminal 1 when the terminal 2 transmits the approval / disapproval final decision message 408 in FIG. 11 and the terminal 1 receives the message.

  When the message processing module of the terminal 1 receives the message 408, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 2 (sequence 1700 to 1700). 1705). Then, the decrypted message content and the attached permission ticket (1-2) are delivered to the control module (sequence 1706).

  The control module knows from the decrypted message content that the terminal 2 has finally expressed its intention to agree. The control module stores the permission ticket (1-2) in the database (sequences 1707 and 1708).

  The control module returns a response message 409 to the terminal 2 (sequences 1709 to 1713).

  The control module receives the final decision message for approval / disapproval from all the member terminals and knows that all the member terminals agree.

  The control module must send a final result notification message to inform that all member terminals are in favor.

  First, the control module requests the connection establishment information generation module to generate connection establishment information (sequence 1714).

  The connection establishment information generation module generates connection establishment information (1-1), stores it in the database, and returns it to the control module (sequences 1715 to 1717).

  The control module requests the VSS distributed encoding module to perform distributed encoding with the threshold (2, 2) on the generated connection establishment information (1-1) (sequence 1718).

  The VSS distributed coding module performs distributed coding on the connection establishment information (1-1) with the threshold (2, 2), and generates the generated connection establishment information share (1-1-1) and connection establishment information share (1-1-2). ) Is saved in the database, and the remaining connection establishment information shares are returned to the control module (sequences 1719 to 1721).

  The control module requests the message generation module to transmit a final result notification message with the connection establishment information share (1-1-2) attached to the content informing that all the member terminals are in agreement (sequence 1722). At this time, the session key with the terminal 2 and the connection establishment information share (1-1-2) are passed to the message generation module.

  The message generation module generates a message with the connection establishment information share (1-1-2) attached to the content informing that all the member terminals agree, performs a message encryption process, and sends a final result notification message through the message processing module. 410 is transmitted (sequences 1723 to 1726).

  After transmitting the final result notification message 410, the response message 411 is received from the terminal 2 (sequences 1727 to 1728).

  In FIG. 12, sequences 1700, 1713, 1726, and 1727 correspond to the messages 408, 409, 410, and 411 of FIG.

  FIG. 13 is a sequence diagram illustrating module processing in the terminal 1 until the terminal 1 transmits a community invitation message 412 to the terminal 3.

  In order to transmit a community invitation message to the terminal 3, the control module of the terminal 1 must first generate a permission ticket in its own terminal in addition to the permission tickets acquired from all member terminals.

  The control module inquires of the database about the permission information share (1-2-1) and the public key of the terminal 3 distributed when the approval / disapproval primary decision message 405 is received from the terminal 2 (sequences 1800 and 1801). Then, the information including the permission information share (1-2-1) and the destination information of the own terminal is encrypted with the public key of the terminal 3 (sequences 1802 and 1803). Thereby, the permission ticket (1-3) is generated.

  The control module requests the common key generation module to create a session key to be shared with the terminal 3 (sequence 1804). The common key generation module generates a session key and stores it in the database (sequences 1805 and 1806), and then passes the session key to the control module (sequence 1807).

  The control module requests the message generation module to create an electronic signature and an encrypted community invitation message (sequence 1808). At this time, the permission ticket (1-2), the permission ticket (1-3), the public key of the terminal 3, and the session key with the terminal 3 are delivered to the message generation module.

  The message generation module generates a message in which the permission ticket (1-2) and the permission ticket (1-3) are attached to the contents of the invitation to the community 200, performs a message electronic signature / encryption process, and performs a message processing module. Then, a community invitation message 412 is transmitted to terminal 3 (sequences 1809 to 1818).

  In FIG. 13, a sequence 1818 corresponds to the message 412 in FIG.

  FIG. 14 is a sequence diagram showing module processing in the terminal 3 when the terminal 3 receives the community invitation message 412 from the terminal 1.

  When the message processing module of the terminal 3 receives the message 412 from the terminal 1, it performs a message decryption process via the message analysis module in order to decrypt the electronic signature and the encrypted message (sequence 1900 to 1927). . Then, the decrypted message content and the attached permission ticket (1-2), permission ticket (1-3), and session key shared with the terminal 1 are passed to the control module (sequence 1928).

  The control module knows from the decrypted message content that the terminal 1 wishes to invite the terminal 3 to the community 200. Here, when the terminal 3 determines whether or not to join / subscribe to the community 200, it is necessary to know what kind of terminal the terminal is joining / subscribing to the community 200 is. However, at this point, it is not possible to know a list of all terminals that have joined or joined the community 200.

  Therefore, the control module decrypts the permission ticket (1-2) and the permission ticket (1-3) with the secret key of the terminal 3 in order to know all the terminals participating / subscribing to the community 200 (sequence 1929- 1932).

  From the obtained permission information share (1-2-1), permission information share (1-2-3), and destination information of the terminal 1 and the terminal 2, the control module of the terminal 3 participates in / joins the community 200 All terminals (terminal 1 and terminal 2) are grasped.

  In FIG. 14, sequences 1900, 1915, and 1916 correspond to the messages 412, 413, and 414 in FIG.

  FIG. 15 is a sequence diagram showing module processing in the terminal 3 when the terminal 3 transmits the connection establishment request message to the terminal 2 after the terminal 3 processes the community invitation message 412 received from the terminal 1 in FIG. .

  The control module of the terminal 3 queries the database for the public key necessary to establish a secure connection with the terminal 2 (sequence 2000, 2001), and if not, makes an acquisition request to the external public key server 5 ( Sequence 2002-2009). Then, after acquiring the public key, the control module asks the intention input module for decision making regarding participation / subscription in the community 200 (sequence 2010). Here, it is assumed that the intention input module has a willingness to participate in or join the community 200 of the terminal 3. The intention input module informs the control module of the intention to join / join the community 200 (sequence 2011).

  The control module obtains all permission information shares (permission information share (1-2-1), permission information share (1-2-3)), destination information of terminal 1, destination information of terminal 2, and sharing with terminal 1 The session key to be executed and the public key of the terminal 2 are stored in the database (sequences 2012 and 2013).

  In order to transmit the connection establishment request message to the terminal 2, the control module requests the common key generation module to generate a session key to be shared with the terminal 2 (sequence 2014).

  The common key generation module stores the generated session key in the database (sequences 2015 and 2016), and passes the session key to the control module (sequence 2017).

  The control module requests the message generation module to transmit a connection establishment request message to the terminal 2 (sequence 2018). At this time, the session key with terminal 2, all permission information shares, and the public key of terminal 2 are passed to the message generation module.

  The message generation module generates a message with all permission information shares attached to the contents of the connection establishment request, performs a message electronic signature / encryption process, and transmits a connection establishment request message 413 to the terminal 2 through the message processing module ( Sequence 2019-2028).

  In FIG. 15, sequences 2004, 2005, and 2028 correspond to the messages 415, 416, and 417 in FIG.

  FIG. 16 is a sequence diagram showing module processing in the terminal 2 when the terminal 2 receives the connection establishment request message 417 transmitted from the terminal 3 in FIG.

  When the message processing module of the terminal 2 receives the message 417, it performs a message decryption process via the message analysis module in order to decrypt the digitally signed and encrypted message (sequence 2100 to 2115). Then, the decrypted message content, the share of all permission information attached, and the session key shared with the terminal 3 are passed (sequence 2116).

  The control module knows from the decrypted message content that the terminal 3 requests establishment of a connection with the terminal 2. Participation / subscription to community 200 requires the approval of all terminals participating / subscribing to the community 200. Therefore, it is obtained from terminal 3 whether or not terminal 3 has the right to participate / subscription by approval of all terminals. Check using all permitted information shares.

  The control module passes all permission information shares (permission information share (1-2-1), permission information share (1-2-3)) to the permission information comparison module, and the permission information share (1- 2-2) and permission information (1-2) are used to request that the terminal 3 check whether all the other terminals of the community 200 have the right to join / join the community 200 (sequence 2117). ). At this time, the destination information of the terminal 3 is passed at the same time.

  The permission information comparison module inquires of the database about permission information share (1-2-2) and permission information (1-2) (sequences 2118 and 2119). Then, for the VSS decryption module, the permission information is decrypted from the permission information share (1-2-1), the permission information share (1-2-2), and the permission information share (1-2-3). Request (sequence 2120).

  The VSS decoding module passes the permission information (1-2-A) generated by decoding from the three permission information shares to the permission information comparison module (sequence 2121).

  The permission information comparison module compares the permission information (1-2) and the permission information (1-2-A) and checks whether there is any difference. If there is a difference, it is regarded as invalid and the connection is not established. If there is no difference, the difference between the time information at the time of comparison and the time information included in the permission information (1-2) is calculated, and it is confirmed that the time has not passed for a certain time. If it has not elapsed, it is determined that the information is normal, and the destination information of the terminal 3 is compared, and it is compared whether there is any difference from the destination information of the terminal 3 included in the permission information (1-2).

  When the above comparison ends normally, a normal response is returned to the control module (sequence 2122).

  If the above check is performed and there is no fraud in all permission information shares, it is determined that the terminal 3 has obtained approval from all terminals for participation / subscription in the community 200. Then, the connection establishment request is accepted, and the session key with the terminal 3 is stored in the database (sequence 2123, 2124). Also, the database is inquired of the connection establishment information share (1-1-2) (sequences 2125 and 2126).

  The control module requests the message generation module to transmit a response message with the connection establishment information share (1-1-2) attached to the terminal 3 (sequence 2127). At this time, the session key shared with the terminal 3 and the connection establishment information share (1-1-2) are passed to the message generation module.

  The message generation module generates a message with the connection establishment information share (1-1-2) attached to the content of the consent to the connection establishment request, performs a message encryption process, and then sends a response message to the terminal 3 through the message processing module. 418 is transmitted (sequence 2128 to 2131).

  After transmitting the response message 418, the terminal 2 receives a connection establishment confirmation message 419 from the terminal 3. Then, it is known from the message content that the connection is normally established between the terminal 2 and the terminal 3 (sequences 2132 to 2138).

  In FIG. 16, sequences 2100, 2131, and 2132 correspond to messages 417, 418, and 419 in FIG. 6, respectively.

  FIG. 17 is a sequence diagram showing module processing in the terminal 3 when the terminal 3 receives the response message 418 from the terminal 2.

  When the message processing module of the terminal 3 receives the message 418, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 2 (sequence 2200). ~ 2205). Then, the decrypted message content and the connection establishment information share (1-1-2) are transferred to the control module (sequence 2206).

  The control module determines from the decrypted message content that a connection with the terminal 2 can be established. After the acquired connection establishment information share (1-1-2) is stored in the database (sequences 2207 and 2208), a connection establishment confirmation message 419 is transmitted to the terminal 2 (sequences 2209 to 2213).

  In FIG. 17, a sequence 2200 corresponds to the message 418 in FIG. 6, and a sequence 2213 corresponds to the message 419 in FIG.

  FIG. 18 is a sequence diagram showing module processing in the terminal 3 when the terminal 3 transmits a community participation / subscription acceptance message 420 to the terminal 1 after transmitting the connection establishment confirmation message 419.

  The control module of the terminal 3 inquires of the database about the session key shared with the terminal 1 and the connection establishment information share (1-1-2) (sequence 2300, 2301). Then, the session key and the connection establishment information share (1-1-2) are passed to the message generation module, and a request to transmit a community participation / subscription acceptance message is made (sequence 2302).

  The message generation module attaches the connection establishment information share (1-1-2) to the message describing the contents of community participation / subscription acceptance, encrypts it with the session key (sequence 2303, 2304), and then the message processing module. Through (sequence 2305), the community participation / subscription acceptance message 420 is transmitted to the terminal 1 (sequence 2306).

  In FIG. 18, a sequence 2306 corresponds to the message 420 in FIG.

  FIG. 19 is a sequence diagram showing module processing in the terminal 1 when the terminal 1 receives the community participation / subscription acceptance message 420.

  When the message processing module of the terminal 1 receives the message 420, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 3 (sequence). 2400-2405). Then, the decrypted message content and the attached connection establishment information share (1-1-2) are passed to the control module (sequence 2406).

  The control module knows from the decrypted message content that the terminal 3 has accepted participation / subscription into the community 200. In order to establish a connection with the terminal 3, connections with all member terminals (terminals 2) participating in or joining the community 200 other than the terminal 1 must be established. The connection establishment status of the terminal 3 is checked using the information share (1-1-2).

  The control module provides the connection establishment information comparison module to provide the connection establishment information share (1-1-2) and requests the terminal 3 to check whether the connection with the terminal 2 has been established (sequence 2407). .

  The connection establishment information comparison module inquires of the database about connection establishment information share (1-1-1) and connection establishment information (1-1) (sequences 2408 and 2409). Then, the VSS decryption module is requested to provide the connection establishment information share (1-1-1) and the connection establishment information share (1-1-2) and decrypt the connection (sequence 2410).

  The VSS decryption module restores the connection establishment information (1-1-A) from the connection establishment information share (1-1-1) and the connection establishment information share (1-1-2), and sends it to the connection establishment information comparison module. Return (sequence 2411).

  The connection establishment information comparison module compares the connection establishment information (1-1) and the connection establishment information (1-1-A), and checks whether there is a difference. If there is a difference, it is determined that the access of the terminal 3 is illegal. If there is no difference, the difference between the time information at the time of comparison and the time information included in the connection establishment information is calculated, and it is checked whether or not a certain time has elapsed.

  If the above processing ends normally, the connection establishment information comparison module informs the control module that the connection with the terminal 2 has been established (sequence 2412).

  When the connection check using the connection establishment information share ends normally, the control module of the terminal 1 accepts the connection establishment. Then, the control module requests the message generation module to transmit a connection establishment confirmation message (sequence 2413). At this time, the session key shared with the terminal 3 is passed to the message generation module.

  The message generation module generates the contents of the connection establishment confirmation as a message, performs a message encryption process, and then transmits a connection establishment information message 421 to the terminal 4 through the message processing module (sequences 2414 to 2417).

  In FIG. 19, a sequence 2400 corresponds to the message 420 in FIG. 6, and a sequence 2417 corresponds to the message 421 in FIG.

  FIG. 20 is a sequence diagram showing module processing in the terminal 3 when the terminal 3 receives the connection establishment confirmation message 421.

  When the message processing module of the terminal 3 receives the message 421, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 1 (sequence 2500). ~ 2505). Then, the decrypted message content is delivered to the control module (sequence 2506).

  The control module knows that the connection with the terminal 1 has been normally established from the decrypted message.

  As described above, when a new terminal (terminal 3) participates in or joins the community, the member terminal (terminal 2) prepares for voting by entering the permission information share that is information for voting. Voting by submitting a single share of permission information generated by, as an approval vote to the receiving terminal (terminal 1), and centrally managing access rights to the community depending on whether the member terminal submits an approval vote Even if there is no presence, access control for a new terminal can be realized in a full mesh network.

In addition, each member terminal does not depend on the other member terminals, and by independently generating permission information including any random keyword, the other member terminals guess the permission information and illegally generate it. By generating a permission information share, for example, it becomes difficult for all terminals to act as if they were in favor of joining or joining a new terminal community, and each member terminal issues a connection establishment request from the new terminal. When received, whether or not the new terminal has gained approval from joining or joining the community from all other terminals
When the total number of terminals participating or participating in the community is 2, the three permission information shares generated by the SSS from the permission information of the own terminal (the permission information share provided to the receiving terminal and the own terminal submitted to the receiving terminal Each member terminal performs a process of comparing the permission information restored by using the permission information share and the permission information share in the database of the own terminal and the permission information in the database of the own terminal without being illegally operated by other terminals. Can be checked correctly independently.

  In addition, when the total number of terminals participating / subscribing to the community is 2, since there are only 1 member terminals in the community except for the response terminal, it is not necessary to create permission and share verification information by VSS. Therefore, it is only necessary to perform distributed coding by SSS, and the calculation using the permission information share verification information and the share verification module can be omitted.

  Also, assuming that the total number of terminals participating / subscribing to the community is 2, the permission information is distributedly encoded with a threshold value (3, 3), and one of the obtained three permission information shares is always its own terminal. In addition, since the permission information is also stored in the own terminal and is not leaked to other terminals at all, it is possible to prevent other terminals from guessing the permission information.

  Also, assuming that the total number of terminals participating / subscribing to the community is n, basically, the permission information is distributedly encoded with threshold values (n, n), and the receiving terminal and all member terminals do not agree (that is, The new terminal cannot establish a connection with each member terminal, but the required vote can be changed freely by changing the threshold value for distributed encoding. If k is the k number of approval votes (permission information share) out of the number of terminals n, the new terminal can establish a connection with a terminal belonging to the community. The number can be set freely.

  In addition, the permission information share provided to the new terminal is not provided as it is, but it is intercepted by a terminal other than the new terminal by providing it as a permission ticket encrypted with the public key of the new terminal including the destination information. In addition, it is possible to notify the new terminal of destination information of all the terminals participating / subscribing to the community using the permission ticket.

  In addition, each member terminal does not directly provide the share of permission information, which is voting information, directly to the new terminal, but collects it once at the receiving terminal, so that the new terminal requests each member terminal to establish a connection. It is possible to handle the sharing of permission information required when performing Thus, simultaneous access that may occur by each member terminal accessing the new terminal in order to directly provide the permission information share to the new terminal can be prevented.

  Also, by setting the time information in the permission information, it is possible to set an expiration date until the new terminal establishes a connection with each member terminal, improving the security level, and in the permission information comparison module, An arbitrary security level can be set by freely setting a reference effective time.

  In addition, in order for the receiving terminal to check whether or not the member terminal has established a connection with the new terminal, the receiving terminal obtains connection establishment information and two connection establishment information shares that are distributedly encoded using threshold values (2, 2). After the member terminal submits the permission information share that is a vote of approval, the receiving terminal distributes one connection establishment information share to the member terminal, and when the member terminal establishes a connection with the new terminal, the receiving terminal in advance The connection establishment information share acquired from the terminal is passed to the new terminal, and then the connection establishment information share acquired from the member terminal when the new terminal establishes a connection with the reception terminal is passed to the reception terminal. That one connection establishment information share and the connection managed by the internal database By using the standing information share and the VSS decoding module, the connection establishment information is restored, and by comparing the restored connection information with the connection establishment information managed in the database inside the reception terminal, the reception terminal It is possible to check whether or not a connection with a member terminal has been established, and it is possible to create a situation in which a connection must be established with all member terminals when establishing a connection with a corresponding terminal.

  In addition, by setting time information in the connection establishment information, it is possible to set an expiration date until the new terminal establishes a connection with the receiving terminal, thereby improving the security level and comparing the connection establishment information. In the module, it is possible to set an arbitrary security level by freely setting a reference effective time.

  Also, messages exchanged between each terminal must be digitally signed and encrypted, or encrypted with a session key shared by each other after authentication by the electronic signature, so that various information exchanged by each terminal ( Permission information share, destination information, connection establishment information, connection establishment information share) can be prevented from being intercepted by a third party.

  Further, according to the present invention, any type of information that can identify a terminal can be applied to the destination information, and for example, an IP address or a SIP address can be applied.

[Second Embodiment]
In FIG. 21, connection 10 has already been established between terminal 1 and terminal 2, connection 11 has been established between terminal 2 and terminal 3, connection 12 has been established between terminal 3 and terminal 1, and the total number of terminals is 3. It is explanatory drawing which shows the message exchanged between terminals required in order to invite the terminal 4 to the community 201 from the state in which the community 201 was formed as a new terminal from the community 201 side.

  In FIG. 21, it is assumed that the terminal 4 that wants to invite the terminal 4 to the community 201 is the terminal 3 (that is, the terminal 3 is a service terminal, the terminal 4 is a new terminal, and the member terminals are the terminal 1 and the terminal 2). The terminal 3 queries the internal database for the public key of the terminal 4, and if not, queries the external public key server 5 and acquires it (messages 500 and 501). The public key is required later to establish a secure connection with the terminal 4.

  The terminal 3 transmits community participation / subscription inquiry messages 502 and 503 indicating the contents of the invitation request to the terminals 1 and 2. At this time, the destination information of the terminal 4 is not attached as it is to the message, but VSS is used to perform distributed encoding with the threshold (2, 2), the destination information share (2-3-1), and the destination information share. (2-3-2), destination information share verification information (2-3) is generated, and the message 502 includes a destination information share (2-3-1) and destination information share verification information (2-3). Is attached to the message 503 with the destination information share (2-3-2) and the destination information share verification information (2-3).

  Upon receiving the community participation / subscription inquiry message 502, the terminal 1 knows that the terminal 3 wishes to invite the terminal 4 to the community 201 from the message content. At the same time, the destination information share (2-3-1) and destination information share verification information (2-3) of the terminal 4 are acquired. However, since the destination information share is attached to the message, the actual destination information of the terminal 4 is not known at this point.

  Since the destination information share (2-3-2) is necessary for the terminal 3 to know the actual destination information of the terminal (terminal 4) that the terminal 3 wishes to invite, the terminal 1 requests the terminal 2 to acquire the destination information share. A message 504 is transmitted. At this time, the terminal 2 transmits a message with the destination information share (2-3-1) necessary for grasping the actual destination information of the terminal 4.

  The terminal 2 receives the destination information share acquisition request message 504, acquires the destination information share (2-3-1), and then returns a response message 505 attached with the destination information share (2-3-2) to the terminal 1. . Here, in the second embodiment, the destination information share acquisition request message is transmitted from the terminal 1 side, but may be transmitted from the terminal 2 side in some cases.

  When the terminal 1 and the terminal 2 acquire the destination information share (2-3-1) and the destination information share (2-3-2), the destination information share is obtained using the destination information share verification information (2-3). It is checked whether there is any fraud by using VSS, and when the check ends normally, the destination information of the terminal 4 is restored from the two destination information shares.

  The terminal 2 inquires of the internal database whether or not it has the public key of the terminal 4 for securely establishing a connection with the terminal 4, and if not, makes an acquisition request to the public key server 5 (public key acquisition) Request message 506, response message 507). Then, after obtaining the public key, the terminal 2 makes a primary determination as to whether or not to allow the terminal 4 to participate in or join the community 201. Here, it is assumed that the terminal 2 agrees to the invitation.

  The terminal 2 generates permission information (2-2), which is distributed and coded with the threshold values (3, 3) by VSS, and permits information share (2-2-1) and permission information share (2-2-2). , Permission information share (2-2-3) and permission information share verification information (2-2) are generated.

  Of the permission information (2-2) and the three permission information shares, one permission information share (here, permission information share (2-2-2)) is the connection between the terminal 2 and the terminal 4 When the establishment request is received, it is necessary for the terminal 4 to confirm whether or not the terminal 4 has approved the participation / subscription of the community 201 for all the terminals participating / subscribing to the community. Save to.

  The voting terminal 2 attaches the permission information share (2-2-1) and the permission information share verification information (2-2) to the terminal 1 as voting information necessary for the final decision of approval or disapproval An information providing message 508 is transmitted. Then, the response message 509 is received from the terminal 1.

  Similarly, the terminal 2 uses a primary decision making message 510 for approval / disapproval as a response message to the community participation / subscription inquiry message 503 received from the terminal 3, the permission information share (2-2-3) as the voting information and the permission information share verification. Attach the usage information (2-2).

  In order for the terminal 4 to participate in or join the community, it is necessary to share permission information from all terminals at the time of final decision of approval or disapproval.

  Similarly, the terminal 1 inquires of the internal database whether or not it has the public key of the terminal 4 necessary for establishing a secure connection with the terminal 4, and if not, the acquisition request is made to the public key server 5. (Public key acquisition request message 511, response message 512). Then, after obtaining the public key, the terminal 1 makes a primary determination as to whether or not to allow the terminal 4 to participate in or join the community 201. Here, it is assumed that the terminal 1 agrees to the invitation.

  The terminal 1 generates permission information (2-1), which is distributed and coded with the threshold values (3, 3) by VSS, and permits information share (2-2-1) and permission information share (2-1-2). , Permission information share (2-1-3) and permission information share verification information (2-1) are generated.

  Of the permission information (2-1) and the three permission information shares, one permission information share (here, the permission information share (2-1-1)) is established by the terminal 1 establishing a connection with the terminal 4. When the request is received, it is necessary for the terminal 4 to confirm whether or not the terminal 4 has approved the participation / subscription of the community 201 with respect to all the terminals participating / subscribing to the community. Save to.

  The voting terminal 1 attaches a permission information share (2-1-2) and permission information share verification information (2-1) as voting information necessary for the final decision of approval or disapproval to the terminal 2 An information provision message 513 is transmitted. Then, the response message 514 is received from the terminal 2.

  Similarly, the terminal 1 uses a primary decision-making message 515 for approval / disapproval as a response message of the community participation / subscription inquiry message 502 received from the terminal 3, the permission information share (2-1-3) as the voting information and the permission information share verification. The business information (2-1) is attached and transmitted.

  Next, the terminal 1 receives the voting information provision message 508 from the terminal 2, and obtains permission information share (2-2-1) and permission information share verification information (2-2) as voting information. To do.

  The acquired permission information share (2-2-1) is necessary as an approval vote at the time of final decision of approval or disapproval, and the permission information share verification information (2-2) is for checking the share fraud. Save it in the database because it is necessary.

  Similarly, the terminal 2 receives the voting regimen provision message 513 from the terminal 1, and acquires permission information share (2-1-2) and permission information share verification information (2-1) which are voting information. To do.

  The acquired permission information share (2-1-2) is necessary as an approval vote at the time of final decision of approval or disapproval, and the permission information share verification information (2-1) is for checking the share fraud. Save it in the database because it is necessary.

  The terminal 3 receives primary and negative primary decision messages 515 and 510 as response messages of the community participation / subscription inquiry messages 502 and 503 transmitted to the terminal 1 and the terminal 2, respectively.

  Then, from each message, it is known that all member terminals agree. Also, permission information share (2-1-3), permission information share verification information (2-1), permission information share (2-2-3), and permission information share verification information (2-2) are acquired. .

  The acquired permission information share (2-1-3) and permission information share (2-2-3) agree with the terminal itself when the final decision message of approval / disapproval from the terminal 1 and the terminal 2 is received as an approval vote. The permission information share verification information (2-1) and the permission information share verification information (2-2) are necessary for checking the share fraud. Therefore, these are stored in the database.

  Since the terminal 3 has received the primary decision message for approval / disapproval from all the member terminals (terminal 1 and terminal 2), the terminal 3 transmits a primary result notification message to all the member terminals. At this time, if all the member terminals indicate approval, it is notified that voting is possible, and otherwise, it is notified that voting is impossible.

  The terminal 3 transmits to the terminal 1 a primary result notification message 516 indicating that voting is possible. Similarly, a primary result notification message 518 is transmitted to the terminal 2. After transmitting the messages 516 and 518, response messages 517 and 519 are received from the terminal 1 and the terminal 2, respectively.

  On the other hand, the terminal 1 receives the primary result notification message 516 from the terminal 3, and all the member terminals agree to the participation / subscription to the community 201 of the terminal 4 in the primary decision message of approval / disapproval and can vote. know. Then, a response message 517 is transmitted to the terminal 3.

  Similarly, the terminal 2 receives the primary result notification message 518 from the terminal 3, and all member terminals agree to the participation / subscription to the community 201 of the terminal 4 in the primary decision message of approval / disapproval, and can vote. Know. Then, a response message 519 is transmitted to the terminal 3.

  Next, the terminal 1 makes a final decision regarding approval or disapproval. Here, it is assumed that the terminal 1 finally agrees to participate / subscribe to the community 201 of the terminal 4.

  The terminal 1 uses the permission information share verification information (2-2) for the permission information share (2-2-1) acquired from the terminal 2, and then checks whether there is any fraud. The permission information share (2-2-1) including the destination information is encrypted with the public key of the terminal 4. This is the permission ticket (2-1).

  The terminal 1 finally attaches a permission ticket (2-1) to the content indicating that the terminal 4 is in favor of joining / subscribing to the community 201, and transmits the approval / disapproval final decision message 520. Then, the response message 521 is received from the terminal 3.

  Similarly, the terminal 2 makes a final decision on pros and cons. Here, it is assumed that the terminal 2 finally agrees to participate / subscribe to the community 201 of the terminal 4.

  The terminal 2 uses the permission information share verification information (2-1) for the permission information share (2-1-2) acquired from the terminal 1, and checks whether there is any fraud. The permission information share (2-1-2) including the destination information is encrypted with the public key of the terminal 4. This is the permission ticket (2-2).

  The terminal 2 finally attaches a permission ticket (2-2) to the content indicating that the terminal 4 is in favor of joining / subscribing to the community 201, and transmits the approval / disapproval final decision message 522. Then, the response message 523 is received from the terminal 3.

  On the other hand, the terminal 3 receives the final decision message 520 for approval / disapproval from the terminal 1, receives the permission ticket (2-1), and receives the final decision message 522 for approval / disapproval from the terminal 2, and receives the permission ticket (2-2). And store them in an internal database.

  The terminal 3 knows from the message content that all the member terminals (terminal 1 and terminal 2) have finally expressed their willingness to participate in or join the community 201 of the terminal 4. Then, the response message 521 is transmitted to the terminal 1 and the response message 523 is transmitted to the terminal 2.

  The terminal 3 generates connection establishment information (2-3) and stores it in the database. Then, the connection establishment information (2-3) is distributedly encoded with the threshold value (3, 3) by VSS, and the generated connection establishment information share (2-3-1) and connection establishment information share (2-3-2) are generated. , One of the connection establishment information shares (2-3-3) (here, connection establishment information share (2-3-3)) is stored in the database.

  The terminal 3 displays a final result notification message 524 in which the connection establishment information share (2-3-1) is attached to the content informing that all the member terminals agree to the participation / subscription of the terminal 4 to the community 201. Send to.

  Similarly, the terminal 3 transmits to the terminal 2 a final result notification message 526 in which the connection establishment information share (2-3-2) is attached to the content informing that all the member terminals agree.

  On the other hand, the terminal 1 receives the final result notification message 524, and all the member terminals finally know that they are in favor of joining / subscribing to the community 201 of the terminal 4. Also, the connection establishment information share (2-3-1) is acquired. Then, a response message 525 is transmitted to the terminal 3.

  Similarly, the terminal 2 receives the final result notification message 526, and all the member terminals finally know that they are in favor of joining / subscribing to the community 201 of the terminal 4. Also, the connection establishment information share (2-3-2) is acquired. Then, a response message 527 is transmitted to the terminal 3.

  On the other hand, the terminal 3 receives response messages 525 and 527 from the terminal 1 and the terminal 2, respectively. Then, in order to generate its own approval vote, the terminal 3 first determines whether the permission information share (2-1-3) and the permission information share (2-2-3) are fraudulent. A check is performed using the verification information (2-1) and the permission information share verification information (2-2), the address information of the terminal itself is encrypted with the public key of the terminal 4, and the permission ticket (2- 3) is generated.

  Then, a community invitation message 528 attached with all permission tickets (permission ticket (2-1), permission ticket (2-2), permission ticket (2-3)) is transmitted to the terminal 4. At this time, the message is digitally signed and encrypted.

  Terminal 4 receives community invitation message 528 and decrypts the message. Here, the public key of the terminal 3 is required, but if it is not stored in the database, an acquisition request is made to the external public key server 5 (messages 529 and 530). The terminal 3 knows from the decrypted message content that it wishes to invite the terminal 4 to the community. Moreover, all permission tickets are acquired.

  The terminal 4 decrypts all permission tickets encrypted with the public key of the terminal 4 with the secret key in order to check what terminals are participating in or joining the community 201. And by permission, permission information share (2-1-3), permission information share (2-2-3), permission information share (2-2-1), permission information share (2-1-2) and The destination information of the terminal 1, the terminal 2, and the terminal 3 is obtained, and it is known that the terminals participating in and joining the community 201 are the terminal 1, the terminal 2, and the terminal 3.

  It is assumed that the terminal 4 is in favor of the community 201 invitation. The terminal 4 queries the internal database for the public keys of the terminal 1 and the terminal 2 in order to establish a secure connection with the terminal 1 and the terminal 2, and makes an acquisition request to the external public key server 5 if it does not have it. (Public key acquisition request message 531 and response message 532).

  The terminal 4 obtains all acquired permission information shares (permission information share (2-1-3), permission information share (2-2-3), permission information share (2-2-1), permission information share (2-1). -2)) including the connection establishment request message 533 is transmitted to the terminal 1.

  When the terminal 1 receives the connection establishment request message 533 from the terminal 4, it is determined whether or not the terminal 4 has obtained permission for participation / subscription from all other terminals of the community 201 using the attached all permission information share. To check.

  First, use permission information share (2-1-1), acquired permission information share (2-1-2), and permission information share (2-1-3) held in the internal database of terminal 1. Then, decryption is performed by VSS to obtain permission information (2-1-A).

  Then, the permission information (2-1) generated by the terminal 1 held in the internal database is compared with the permission information (2-1-A) to check whether there is any difference. If there is a difference, the access of the terminal 4 is regarded as illegal (that is, it is not approved by all other terminals in the community), and the connection is not established. If there is no difference, the difference between the time information at the time of comparison and the time information included in the permission information is calculated. If the value is equal to or longer than a certain time, it is determined to be illegal and the connection is not established. If there is no fraud, it is further determined whether the destination information described in the permission information is the same as that of the terminal 4, and if there is a difference, the connection is not established.

  When the above check is completed normally, next, whether or not the remaining permission information share (2-2-3) and permission information share (2-2-1) are fraudulent is checked (2 -2) is used to verify and check for fraud.

  If the above check is performed and the process ends normally, the terminal 1 transmits to the terminal 4 a response message 534 attached with the connection establishment information share (2-3-1) held in the internal database. After transmitting the response message 534, the terminal 1 receives the connection establishment confirmation message 535 from the terminal 4.

  Upon receiving the response message 534, the terminal 4 stores the connection establishment information share (2-3-1) in an internal database, and then transmits a connection establishment confirmation message 535 to the terminal 1.

  After establishing the connection with the terminal 1, the terminal 4 further transmits a connection establishment request message 536 including the entire permission information share to establish a connection with the terminal 2.

  The process until the connection is established between the terminal 4 and the terminal 2 is the same as that in the case of the terminal 1 (messages 533 to 535). When the terminal 2 receives the connection establishment request message 536 from the terminal 4, it is attached. Among all permission information shares, permission information share (2-2-1), permission information share (2-2-3), and permission information share (2-2-2) stored in the internal database are used. The permission information is restored by VSS (permission information (2-2A)), and the permission information (2-2A) is compared with the permission information (2-2) stored in the internal database. .

  Then, using the permission information share verification information (2-1), verify whether the remaining permission information share (2-1-3) and permission information share (2-1-2) are fraudulent. Do.

  If the above check is performed and the processing ends normally, the terminal 2 transmits a response message 537 attached with the connection establishment information share (2-3-2) to the terminal 4. After transmitting the response message 537, the terminal 2 receives the connection establishment confirmation message 538 from the terminal 4.

  Upon receiving the response message 537, the terminal 4 stores the connection establishment information share (2-3-2) in the internal database, and then transmits a connection establishment confirmation message 538 to the terminal 2.

  When the terminal 4 establishes a connection with the terminal 1 and the terminal 2, the community participation / subscription consent with the connection establishment information share (2-3-1) and the connection establishment information share (2-3-2) attached to the terminal 3 is established. A message 539 is transmitted.

  The terminal 3 receives the community participation / subscription acceptance message 539 from the terminal 4 and acquires the connection establishment information share (2-3-1) and the connection establishment information share (2-3-2). Then, in order to confirm whether the terminal 4 has established connections with all other terminals in the community, the connection establishment information share (2-3-1), the connection establishment information share (2-3-2), and the internal The connection establishment information is decrypted by VSS from the connection establishment information share (2-3-3) in the database. The obtained connection establishment information (2-3-A) is compared with the connection establishment information (2-3) held in the internal database to check whether there is any difference.

  If there is a difference, the terminal 4 determines that connections with all member terminals have not been established, and the terminal 3 does not establish a connection with the terminal 4. If there is no difference, it is checked whether or not the difference between the time information included in the connection establishment information and the time information at the time of comparison is within a certain time. If it is longer than a certain time, the connection is not established.

  With the above processing, the establishment of connections between the terminal 4 and all member terminals is confirmed. Then, the terminal 3 transmits a connection establishment confirmation message 540 to the terminal 4 and establishes a connection with the terminal 4.

  As described above, by exchanging the messages 500 to 540 among the terminal 1, the terminal 2, the terminal 3, the terminal 4, and the public key server 5, the terminal 4 is newly invited to the community 201. When the total number of terminals in the community is 3 or more, new messages are invited to the community by exchanging similar messages.

  22 to 46 are sequence diagrams showing in detail a process in which each terminal processes a message exchanged between the terminals in FIG. 21 using an internal module.

  FIG. 22 is a sequence diagram showing module processing in the terminal 3 until the terminal 3 transmits a message (community participation / subscription inquiry message) indicating the contents of the terminal 4 to be accepted or rejected to the terminal 4 to the terminal 1 and the terminal 2. .

  The control module of terminal 3 inquires of the database about the destination information of terminal 4, the session key shared with terminal 1 and terminal 2, and the public key of terminal 4 (sequences 2600 and 2601). If the public key of the terminal 4 is not in the database, the public key of the terminal 4 is inquired to the external public key server 5 (sequence 2602 to 2607) and stored in the database (sequence 2608, sequence 2609).

  The control module inquires of the destination information of the terminal 4 from the database (sequences 2610 and 2611), performs distributed encoding with the threshold values (2, 2), and performs destination information sharing (2-3-1) and destination information sharing (2- 3-2) and further destination information share verification information (2-3) is acquired (sequences 2612 and 2613).

  First, in order to transmit a community participation / subscription request message to the terminal 1, the control module asks whether or not the terminal 4 invites the approval or disapproval of the destination information share (2-3-1), destination information share verification information ( The control module requests the message generation module to generate a message attached with 2-3) and transmit it to the terminal 1 (sequence 2614). At this time, the session key of the terminal 1, the destination information share (2-3-1), and the destination information share verification information (2-3) are handed over at the same time.

  The message generation module generates a message with the destination information share (2-3-1) and the destination information share verification information (2-3) attached to the contents of the terminal 4 asking for approval or disapproval, and performs a message encryption process. After that, a community participation / subscription inquiry message 502 is transmitted to the terminal 1 (sequences 2615 to 2618).

  Similarly, the control module generates a message with the destination information share (2-3-2) and the destination information share verification information (2-3) attached to the content asking for approval or disapproval for the invitation of the terminal 4 through the message generation module. After performing the message encryption process, a community participation / subscription inquiry message 503 is transmitted to the terminal 2 (sequences 2619 to 2623).

  In FIG. 22, sequences 2604, 2605, 2618, and 2623 correspond to the messages 500, 501, 502, and 503 in FIG.

  FIG. 23 is a sequence diagram showing processing of modules in the terminal 1 when the terminal 1 receives the community participation / subscription inquiry message 502 transmitted by the terminal 3 in FIG.

  Upon receiving the message 502, the message processing module of the terminal 1 performs a message decryption process via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 3 (sequence 2700 to 2705). Then, the contents of the decrypted message, the attached destination information share (2-3-1), and destination information share verification information (2-3) are passed to the control module (sequence 2706).

  The control module knows from the decrypted message that the terminal 3 wishes to invite the community 4 of the terminal 4. However, the actual destination information of the terminal 4 has not yet been obtained at this point. Since the remaining destination information share is necessary to obtain the actual destination information of the terminal 4, the destination information share must be acquired from all member terminals (terminal 2) other than the reception terminal (terminal 3).

  The control module saves the destination information share (2-3-1) and the destination information share verification information (2-3) in the database (sequence 2707, 2708), and then queries the database for the session key shared with the terminal 2. (Sequence 2709, 2710). Then, the message generation module is requested to transmit a destination information share acquisition request message with the destination information share (2-3-1) attached (sequence 2711). At this time, the destination information share (2-3-1) and the session key are passed to the message generation module.

  The message generation module performs a message encryption process on the message with the destination information share acquisition request attached to the content of the destination information share acquisition request, and then sends the message as a destination information share acquisition request message 504 through the message processing module. It transmits to the terminal 2 (sequence 2712 to 2715).

  In FIG. 23, sequences 2700 and 2715 correspond to the messages 502 and 504 in FIG. 21, respectively. In this embodiment, it is assumed that the terminal 1 first transmits a destination information share acquisition request message to the terminal 2. An earlier message transmission and reception timing wins. In some cases, a destination information share acquisition request message transmitted by the terminal 2 arrives at the terminal 1 first.

  FIG. 24 shows a case where the terminal 2 receives the community participation / subscription inquiry message 503 transmitted from the terminal 3, performs the same processing as in FIG. 23, and then receives the destination information share acquisition request message 504 from the terminal 1. FIG. 6 is a sequence diagram showing module processing in the terminal 2.

  When the message processing module of the terminal 2 receives the destination information share acquisition request message 504 from the terminal 1, the message encrypted by the session key shared with the terminal 1 is decrypted via the message analysis module. A decoding process is performed (sequence 2800 to 2805). Then, the contents of the decrypted message and the attached destination information share (2-3-1) are passed to the control module (sequence 2806).

  The control module knows from the decrypted message content that the terminal 1 is requesting destination information sharing. The control module stores the destination information share (2-3-1) acquired from the terminal 1 in the database (sequence 2807, 2808), and stores the destination information share (2-3-2) acquired from the terminal 3 in the database. The session key shared with the server is inquired (sequence 2809, 2810).

  The control module requests the message generation module to generate a response message in order to return a response to the destination information share acquisition request message 504 (sequence 2811). At this time, the destination information share (2-3-2) and the session key shared with the terminal 1 are passed.

  The message generation module generates a message with the destination information share (2-3-2) attached to the content of the response message, performs a message encryption process, and then sends a destination information share acquisition request message to the terminal 1 through the message processing module. The response message 505 is transmitted (sequences 2812 to 2815).

  After transmitting the response message 505, the control module uses the destination information share (2-3-1) and the destination information share (2-3-2) to restore the actual destination information of the terminal 4 as follows. .

  First, the destination information share verification information (2-3) acquired from the terminal 3 is checked to determine whether each destination information share is fraudulent.

  The control module inquires of the database about the destination information share (2-3-1) and the destination information share verification information (2-3) (sequences 2816 and 2817), and requests the share verification module to perform verification (sequence 2818). ).

  The share verification module verifies the destination information share (2-3-1), and returns a normal response if there is no fraud (sequence 2819).

  Similarly, the control module uses the destination information share (2-3-2) and the destination information share verification information (2-3) to request the share verification module to verify the destination information share (sequences 2820 to 2823). ).

  When the destination information share fraud check is finished, the control module decrypts the destination information from the destination information share (2-3-1) and the destination information share (2-3-2) (sequences 2824 and 2825). As a result, the control module acquires the actual destination information of the terminal 4. In addition, a public key for establishing a secure connection with the terminal 4 is inquired of the database (sequences 2826 and 2827), and if not, an acquisition request is made to the external public key server 5 (sequences 2828 to 2833). The acquired public key and destination information of the terminal 4 are stored in the database (sequences 2834 and 2835).

  The control module requests the intention input module to determine whether or not the terminal 4 participates or joins the community 201 (sequence 2836). Here, it is assumed that there is an intention of approval by the intention input module. The intention input module informs the control module that there is an intention of approval (sequence 2837). It is assumed that the decision at this point is a primary decision.

  24, sequences 2800, 2815, 2830, and 2831 correspond to messages 504, 505, 506, and 507 in FIG. 21, respectively.

  FIG. 25 is a sequence diagram illustrating module processing in the terminal 1 when the terminal 1 receives the response message 505 transmitted by the terminal 2.

  When the message processing module of the terminal 1 receives the response message 505 from the terminal 2, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 2. Perform (sequence 2900-2905). Then, the contents of the decrypted message and the attached destination information share (2-3-2) are passed to the control module (sequence 2906).

  The control module knows from the decrypted message content that it is a response message to the destination information share acquisition request message 504 transmitted by the terminal. The control module inquires the destination information share (2-3-1) and destination information share verification information (2-3) acquired from the terminal 3 with respect to the database (sequence 2907, 2908). Restore actual destination information.

  First, the destination information share verification information (2-3) acquired from the terminal 3 is checked to determine whether each destination information share is fraudulent.

  The control module passes the destination information share (2-3-1) and the destination information share verification information (2-3) to the share verification module and requests verification (sequence 2909).

  The share verification module verifies the destination information share (2-3-1), and returns a normal response if there is no fraud (sequence 2910).

  Similarly, the control module uses the destination information share (2-3-2) and the destination information share verification information (2-3) to request the share verification module to verify the destination information share (sequences 2911 and 2912). ).

  When the destination information share fraud check is finished, the control module decrypts the destination information from the destination information share (2-3-1) and the destination information share (2-3-2) (sequences 2913 and 2914). As a result, the control module acquires the actual destination information of the terminal 4. Further, a public key for establishing a secure connection with the terminal 4 is inquired of the database (sequences 2915 and 2916), and if not, an acquisition request is made to the external public key server 5 (sequences 2917 to 2922). The acquired public key and destination information of the terminal 4 are stored in a database (sequences 2923 and 2924).

  The control module requests the intention input module to determine whether or not the terminal 4 participates or joins the community 201 (sequence 2925). Here, it is assumed that there is an intention of approval by the intention input module. The intention input module informs the control module that there is an intention of approval (sequence 2926). It is assumed that the decision at this point is a primary decision.

  In FIG. 25, sequences 2900, 2919, and 2920 correspond to messages 505, 511, and 512 in FIG.

  FIG. 26 is a sequence diagram showing module processing in the terminal 1 after the terminal 1 makes a primary decision in FIG.

  In FIG. 25, when the control module is informed by the intention input module of primary decision making in favor of joining / subscribing to the community 201 of the terminal 4 (sequence 2926), the permission information share, which is voting information, is sent to the terminal 2 and the terminal, respectively. In order to distribute to 2, the control module requests the permission information generation module to create permission information (sequence 3000).

  The permission information generation module generates permission information (2-1), saves it in the database (sequence 3001, 3002), and passes it to the control module (sequence 3003).

  The control module requests the VSS distributed encoding module to perform distributed encoding of the permission information (2-1) with the threshold (3, 3) (sequence 3004).

  The VSS distributed coding module performs distributed coding of the permission information (2-1) with the threshold (3, 3), and permits information share (2-1-1), permission information share (2-1-2), permission information share. (2-1-3), permission information share verification information (2-1) is generated, and one permission information share required when a connection establishment request is received from the terminal 4 is stored in one database (here, permission is granted). Information sharing (2-1-1)) (sequence 3005, 3006). Then, the VSS distributed coding module returns the permission information share (2-1-2) and permission information share (2-1-3) to the control module (sequence 3007).

  The control module inquires of the database about the session keys of the terminals 2 and 3 (sequences 3008 and 3009). Then, the control module requests the message generation module to transmit a message with the permission information share (2-1-2) and permission information share verification information (2-1) attached to the terminal 2 ( Sequence 3010). At this time, the permission information share (2-1-2), the session key shared with the terminal 2, and the permission information share verification information (2-1) are passed to the message generation module.

  The message generation module generates a message with permission information share (2-1-2) and permission information share verification information (2-1) attached to the contents of the voting information provision, and after performing the message encryption process, Through the message processing module, the information is transmitted to the terminal 2 as a voting information provision message 513 (sequences 3010 to 3014).

  Similarly, the control module of the terminal 1 requests the message generation module to transmit a message attached with the permission information share (2-1-3) and permission information share verification information (2-1) to the terminal 3. (Sequence 3015).

  The message generation module generates a message with permission information share (2-1-3) and permission information share verification information (2-1) attached to the intention content of the primary approval, and after performing the message encryption process, the message Through a processing module, it transmits to terminal 3 as a primary decision message 515 for approval or disapproval (sequences 3016 to 3019).

  In FIG. 26, sequences 3014 and 3019 correspond to the messages 513 and 515 in FIG.

  FIG. 27 is a sequence diagram showing module processing in the terminal 2 after the terminal 2 makes a primary decision in FIG.

  The processing (sequence 3100-3119) in FIG. 27 is exactly the same as the processing (sequence 3000-3019) in the terminal 1 of FIG. 26, generates permission information (2-2), and further generates permission information (2-2). ), The permission information share (2-2-1), the permission information share (2-2-2), the permission information share (2-2-3), and the permission information with the threshold (3, 3) by using VSS. Share verification information (2-2) is generated, permission information share (2-2-2) is stored in the database of terminal 2, permission information share (2-2-1) and permission information share verification information ( 2-2) is transmitted to terminal 1 as voting information provision message 508 by sequence 3114, and permission information share (2-2-3) and permission information share verification information (2-2) are transmitted to terminal 1 by sequence 3119. Pros and cons of 3 Transmitting the primary decision message 510.

  In FIG. 27, sequences 3114 and 3119 correspond to messages 508 and 510 in FIG. 21, respectively.

  In FIG. 28, the terminal 1 receives the message 514 as a response message of the voting information provision message 513 from the terminal 2, receives the voting information provision message 508 from the terminal 2, transmits the response message 509, and receives the primary message from the terminal 3. FIG. 11 is a sequence diagram showing module processing in the terminal 1 until a result notification message 516 is received and a response message 517 is transmitted. In FIG. 28, the messages 514, 508, and 509 are processed in order, but the order varies depending on the case.

  The control module of terminal 1 receives response message 514 of voting information provision message 513 from terminal 2 (sequence 3200-3206).

  When the message processing module of the terminal 1 receives the message 508 from the terminal 2, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 2 ( Sequence 3207 to 3212). Then, the contents of the decrypted message, the attached permission information share (2-2-1), and permission information share verification information (2-2) are passed to the control module (sequence 3213).

  The control module knows that voting information is attached from the decrypted message content. Then, the control module stores the permission information share (2-2-1) and the permission information share in the database for verification information (2-2) (sequences 3214 and 3215).

  Next, in order to return a response message to the terminal 2, the control module inquires of the database about a session key shared with the terminal 2 (sequences 3216 and 3217), and then transmits a response message to the terminal 2. (Sequence 3218). At this time, a session key shared with the terminal 2 is passed.

  The message generation module generates a response content, performs a message encryption process, and then transmits a response message 509 to the terminal 2 through the message processing module (sequences 3219 to 3222).

  After transmitting the response message 509, the control module of the terminal 1 receives the primary result notification message 516 from the terminal 3 (sequences 3223 to 3229). Then, the control module obtains approval from all the member terminals in the primary decision making messages 515 and 510 of approval / disapproval received from all the member terminals (terminal 1 and terminal 2) by the terminal 3, and the preparation for voting is completed. , Know that voting is possible.

  The control module transmits a response message 517 of the primary result notification message 516 to the terminal 3 through the message generation module (sequences 3230 to 3234).

  After transmitting the response message 517 to the terminal 3, the control module is inquired of the intention input module in order to make a final decision on the approval or disapproval for participation / subscription in the community 201 of the terminal 4 (sequence 3235). Here, it is assumed that the terminal 1 finally agrees to participate / subscribe to the community 201 of the terminal 4. The intention input module communicates the intention indicating approval to the control module (sequence 3236).

  In FIG. 28, sequences 3200, 3207, 3222, 3223, and 3234 correspond to messages 514, 508, 509, 516, and 517 in FIG.

  29, the terminal 2 receives 509 as a response message of the voting information provision message 508 from the terminal 1, receives the voting information provision message 513 from the terminal 1, transmits the response message 514, and receives the primary result from the terminal 3. FIG. 11 is a sequence diagram showing module processing in the terminal 2 until a notification message 518 is received and a response message 519 is transmitted. In FIG. 29, messages 509, 513, and 514 are processed in order, but the order varies depending on the case.

  The process in FIG. 29 (sequence 3300-3336) is exactly the same as the process in FIG. 28 (sequence 3200-3236), and permission information share (2-1-2) and permission information are transmitted from terminal 1 by voting information provision message 513. The share verification information (2-1) is acquired, and in the primary result notification message 518 from the terminal 3, in the primary decision making messages 515 and 510 that the terminal 3 receives from all the member terminals (terminal 1 and terminal 2), Get approval from all the member terminals and know that voting preparation is completed and voting is possible.

  After transmitting the response message 519 to the terminal 3, the control module of the terminal 2 inquires the intention input module in order to make a final decision on the approval or disapproval of the participation or participation in the community 201 of the terminal 4 (sequence 3335). Here, it is assumed that the terminal 2 finally agrees to participate / subscribe to the community 201 of the terminal 4. The intention input module communicates the intention indicating approval to the control module (sequence 3336).

  In FIG. 29, sequences 3300, 3307, 3322, 3323, and 3334 correspond to messages 509, 513, 514, 518, and 519 in FIG.

  FIG. 30 is a sequence diagram showing module processing in the terminal 3 when the primary decision message 515 for approval / disapproval is received from the terminal 1 and when the primary decision message 510 for approval / disapproval is received from the terminal 2. In FIG. 30, the message from the terminal 1 arrives at the terminal 3 first, but in some cases, the message from the terminal 2 may arrive first.

  When the message processing module of the terminal 3 receives the message 515, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 1 (sequence 3400- 3405). Then, the decrypted message contents, attached permission information share (2-1-3), and permission information share verification information (2-1) are passed to the control module (sequence 3406).

  The control module knows that the terminal 1 is willing to give primary approval. The control module stores the acquired permission information share (2-1-3) and permission information share verification information (2-1) in a database (sequences 3407 and 3408).

  When the message processing module of the terminal 3 receives the message 510, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 2 (sequences 3409 to 3409). 3414). Then, the decrypted message content, attached permission information share (2-2-3), and permission information share verification information (2-2) are passed to the control module (sequence 3415).

  The control module knows that the terminal 2 is willing to give primary approval. The control module stores the acquired permission information share (2-2-3) and permission information share verification information (2-2) in the database (sequences 3416 and 3417).

  In FIG. 30, a sequence 3400 corresponds to the message 515 in FIG. 21, and a sequence 3409 corresponds to the message 510 in FIG.

  FIG. 31 shows a terminal in FIG. 30 in which the terminal 3 receives primary approval / disapproval messages (messages 515 and 510) from all member terminals (terminal 1 and terminal 2) and notifies the result to all member terminals. 3 is a sequence diagram showing module processing in FIG.

  Since the terminal 3 has received the primary decision message for approval / disapproval from all the member terminals (terminal 1 and terminal 2), the terminal 3 transmits a primary result notification message to all the member terminals. At this time, if all the member terminals indicate approval, it is notified that voting is possible, and otherwise, it is notified that voting is impossible.

  The control module of the terminal 3 requests the message generation module to transmit a primary result notification message indicating that voting is possible to the terminal 1 (sequence 3500).

  The message generation module generates a message indicating that voting is possible, performs a message encryption process, and transmits a primary result notification message 516 to the terminal 1 via the message processing module (sequence 3501 to 3504). .

  Similarly, primary result notification message 518 is also transmitted to terminal 2 (sequence 3505-3509).

  After transmitting the primary result notification messages 516 and 518, the control module of the terminal 3 receives response messages 517 and 519 from the terminal 1 and the terminal 2, respectively (messages 3510 to 3523).

  In FIG. 31, sequences 3504, 3509, 3510, and 3517 correspond to the messages 516, 518, 517, and 519 of FIG.

  FIG. 32 is a sequence diagram showing module processing of the terminal 1 after the terminal 1 makes a final decision on participation / subscription to the community 201 of the terminal 4 in FIG.

  Since the control module of the terminal 1 is notified of the final decision of approval or disapproval from the intention input module (sequence 3236), the session key shared with the terminal 3, the public key of the terminal 4, the permission information share (2-2) -1) Inquires the database for permission information share verification information (2-2) (sequences 3600 and 3601). Then, whether or not the permission information share (2-2-1) is fraudulent is requested by passing the permission information share (2-2-1) and permission information share verification information (2-2) to the share verification module. (Sequence 3602 and 3603).

  If the permission information share (2-2-1) is not illegal, the permission information share (2-2-1) and the public key of the terminal 4 are passed to the public key cryptosystem encryption module, and encryption is requested (sequence). 3604, 3605). At this time, the destination information of the terminal 1 is also encrypted. Let the generated information be a permission ticket (2-1).

  The control module provides the permission ticket (2-1) and the session key shared with the terminal 3 to the message generation module, and requests the terminal 3 to transmit a final decision message for approval or disapproval (sequence 3606). ).

  The message generation module finally generates a message by attaching a permission ticket (2-1) to the content indicating approval intention, performs a message encryption process, and transmits a final decision message 520 for approval or disapproval through the message processing module. (Sequence 3607 to 3610).

  After transmitting the approval / disapproval final decision message 520, the terminal 1 receives the response message 521 from the terminal 3 (sequences 3611 to 3617).

  In addition, after receiving response message 521, final result notification message 524 is received from terminal 3 (sequences 3618 to 3624).

  From the content of the final result notification message 524, the control module finally knows that all the member terminals are in favor of joining / subscribing to the community of the terminal 4. And connection establishment information share (2-3-1) is acquired.

  The control module stores the acquired connection establishment information share (2-3-1) in the database (sequences 3625 and 3626), and then transmits a response message 525 (sequences 3627 to 3631).

  In FIG. 32, sequences 3610, 3611, 3618, and 3631 correspond to the messages 520, 521, 524, and 525 of FIG.

  FIG. 33 is a sequence diagram illustrating module processing in the terminal 2 after the terminal 2 makes a final decision on participation / subscription to the community 201 of the terminal 4 in FIG.

  The processing in FIG. 33 (sequences 3700 to 3731) is exactly the same as the processing in FIG. 32 (sequences 3600 to 3631).

  After the fraud check of the permission information share (2-1-2), the terminal 2 encrypts the permission information share (2-1-2) together with the destination information of the terminal 2 using the public key of the terminal 4 The permission ticket (2-2) is generated (sequence 3700-3705).

  Then, the approval / disapproval final decision message 522 attached with the permission ticket (2-2) is transmitted to the terminal 3 (sequences 3706 to 3710). After transmitting the approval / disapproval final decision-making message 522, the response message 523 is received (sequence 3711 to 3717).

  After receiving the response message 523, the terminal 3 receives the final result notification message 526 (sequences 3718 to 3724), stores the connection establishment information share (2-3-2) in the database (sequences 3725 and 3726), and then receives the response message. 527 is transmitted (sequences 3727 to 3731).

  33, sequences 3710, 3711, 3718, and 3731 correspond to messages 522, 523, 526, and 527 of FIG. 21, respectively.

  FIG. 34 is a sequence diagram illustrating module processing when the terminal 3 receives a final approval / disapproval message 520 from the terminal 1 and when receiving a final approval / disapproval message 522 from the terminal 2. In the second embodiment, an example in which the message 520 arrives first at the terminal 3 as shown in FIG. 32 is shown, but the message 522 may arrive first in some cases.

  When the message processing module of the terminal 3 receives the message 520 from the terminal 1, it performs a message decryption process via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 1. (Sequence 3800-3805). Then, the obtained message content and the attached permission ticket (2-1) are delivered to the control module (sequence 3806).

  The control module knows from the decrypted message content that the terminal 1 has finally expressed its intention to agree. Then, the control module stores the permission ticket (2-1) in the database (sequences 3807 and 3808).

  The control module returns a response message 521 to the terminal 1 (sequences 3809 to 3813).

  Similarly, when the message processing module of the terminal 3 receives the message 522 from the terminal 2, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 2. Is performed (sequences 3814 to 3819). Then, the obtained message content and the attached permission ticket (2-2) are delivered to the control module (sequence 3820).

  The control module knows from the decrypted message content that the terminal 2 has finally expressed its intention to agree. Then, the control module stores the permission ticket (2-2) in the database (sequences 3821 and 3822).

  Then, the control module returns a response message 523 to the terminal 2 (sequences 3823 to 3827).

  34, sequences 3800, 3813, 3814, and 3827 correspond to messages 520, 521, 522, and 523 in FIG. 21, respectively.

  FIG. 35 shows a terminal after terminal 3 has received a final decision message (messages 520 and 522) from all member terminals (terminal 1 and terminal 2) and has transmitted a response message (messages 521 and 523) to all member terminals. 3 is a sequence diagram showing module processing in FIG.

  The control module receives the approval / disapproval leg week decision message from all the member terminals and knows that all the member terminals are in favor.

  The control module must send a final result notification message to inform that all member terminals are in favor.

  First, the control module requests the connection establishment information generation module to generate connection establishment information (sequence 3900).

  The connection establishment information generation module generates connection establishment information (2-3), stores it in the database, and returns it to the control module (sequences 3901 to 3903).

  The control module requests the VSS distributed encoding module to perform distributed encoding with the threshold (3, 3) on the generated connection establishment information (2-3) (sequence 3904).

  The VSS distributed encoding module performs distributed encoding on the connection establishment information (2-3) with the formula values (3, 3), and generates the generated connection establishment information share (2-3-1) and connection establishment information share (2-3- 2) After saving one of the connection establishment information shares (2-3-) (here, connection establishment information share (2-3-3)) in the database, the remaining connection establishment information shares are stored in the control module. Return (sequence 3905 to 3907).

  The control module requests the message generation module to transmit to the terminal 1 a final result notification message in which the connection establishment information share (2-3-1) is attached to the content informing that all the member terminals agree (sequence 3908). ). At this time, the session key with the terminal 1 and the connection establishment information share (2-3-1) are passed to the message generation module.

  The message generation module generates a message with the connection establishment information share (2-3-1) attached to the content indicating that all the member terminals agree, performs a message encryption process, and sends a final result notification message through the message processing module. 524 is transmitted to the terminal 1 (sequences 3909 to 3912).

  Similarly, the control module transmits a final result notification message 526 attached with the connection establishment information share (2-3-2) to the terminal 2 through the message generation module (sequences 3913 to 3917).

  After transmitting the final result notification messages 524 and 526, the terminal 3 receives response messages 525 and 527 from the terminal 1 and the terminal 2, respectively (sequences 3918 to 3931).

  In FIG. 35, sequences 3912, 3917, 3918, and 3925 correspond to the messages 524, 526, 525, and 527 of FIG.

  FIG. 36 is a sequence diagram showing module processing until the terminal 3 transmits the community invitation message 528 to the terminal 4 after transmitting the final result notification message to all the member terminals (terminal 1 and terminal 2) in FIG. It is.

  In order to transmit a community invitation message to the terminal 4, the control module obtains the approval ticket (2-1) and the permission ticket (2-2) obtained at the time of receiving the final decision message for approval or disapproval from the terminal 1 and the terminal 2, respectively. And permission information share (2-1-3), permission information share verification information (2-1), permission information share (2-2) acquired when receiving the primary decision message of approval / disapproval from the terminal 1 and the terminal 2, respectively. -3), the permission information share verification information (2-2) and the public key of the terminal 4 are inquired of the database (sequence 4000, 4001).

  Similarly to FIGS. 32 and 33, before the permission ticket is generated, fraud checks on the permission information share (2-1-3) and the permission information share (2-2-3) are performed, respectively. 2-1), using permission information share verification information (2-2) (sequence 4002 to 4005).

  When the fraud check is finished, the control module encrypts the information including the permission information share (2-1-3) and the permission information share (2-2-3) with the destination information of the own terminal with the public key of the terminal 4. (Sequence 4006, 4007). This is a permission ticket (2-3).

  The control module requests the common key generation module to create a session key shared with the terminal 4 (sequence 4008). The common key generation module generates a session key, stores it in the database (sequence 4009, 4010), and passes the session key to the control module (sequence 4011).

  The control module requests the message generation module to create an electronic signature and an encrypted community invitation message (sequence 4012). At this time, the permission ticket (2-1), the permission ticket (2-2), the permission ticket (2-3), the public key of the terminal 4, and the session key with the terminal 4 are delivered to the message generation module.

  The message generation module generates a message in which the permission ticket (2-1), the permission ticket (2-2), and the permission ticket (2-3) are attached to the contents of the invitation to the community 201, and the message electronic signature / encryption The terminal 4 transmits a community invitation message 528 through the message processing module (sequences 4013 to 4022).

  In FIG. 36, the sequence 4022 corresponds to the message 528 of FIG.

  FIG. 37 is a sequence diagram illustrating module processing in the terminal 4 when the terminal 4 receives the community invitation message 528 from the terminal 3.

  When the message processing module of the terminal 4 receives the message 528 from the terminal 3, it performs a message decryption process via the message analysis module in order to decrypt the digitally signed and encrypted message (sequences 4100 to 4127). . Then, the decrypted message content and the attached permission ticket (2-1), permission ticket (2-2), permission ticket (2-3), and session key shared with the terminal 3 are delivered (sequence). 4128).

  The control module of the terminal 4 knows from the decrypted message content that the terminal 3 desires an invitation to the community 201 of the terminal 4. Here, when determining whether or not the terminal 4 joins or joins the community, it is necessary to know what terminal is joining or joining the community 201. However, at this point, it is not possible to know a list of all terminals participating in or joining the community 201.

  Therefore, the control module sends the permission ticket (2-1), the permission ticket (2-2), and the permission ticket (2-3) to the secret of the terminal 4 in order to know all the terminals that have joined and joined the community 201. Decryption is performed using the key (sequences 4129 to 4140).

  The control module of the terminal 4 includes the permission information share (permission information share (2-1-2), permission information share (2-1-3), permission information share (2-2-1) included in the permission ticket, Permission information share (2-2-3)) and terminal destination information (terminal 1, terminal 2, and terminal 3 destination information) are acquired, and all terminals participating in / subscribing to the community 201 are terminal 1 and terminal 2 , Know that it is a terminal 3.

  In FIG. 37, sequences 4100, 4115, 4115, and 4116 correspond to messages 528, 529, and 530 in FIG.

  FIG. 38 is a sequence diagram illustrating module processing when the terminal 4 transmits a connection establishment request message to the terminal 1 after processing the invitation message to the community 201 received from the terminal 3 in FIG. .

  In FIG. 37, it is known that the terminals that participate in / subscribe the control module of the terminal 4 to the community 201 are the terminal 1, the terminal 2, and the terminal 3.

  The control module of the terminal 4 queries the database for a public key necessary for establishing a secure connection with the terminal 1 and the terminal 2 (sequence 4200, 4201), and if not, obtains an acquisition request from the external public key server 5 Are performed (sequences 4202 to 4207). Then, after obtaining the public key, the control module asks the intention input module for decision making regarding participation / subscription in the community 201 (sequence 4208). Here, it is assumed that the intention input module has a willingness to participate in or join the community 201 of the terminal 4. The intention input module informs the control module of the intention to join / join the community 201 (sequence 4209).

  The control module obtains all permission information shares (permission information share (2-1-2), permission information share (2-1-3), permission information share (2-2-1), permission information share (2- 2-3)), destination information of terminals (terminal 1, terminal 2, and terminal 3), session key shared with terminal 3, and public keys of terminal 1 and terminal 2 are stored in a database (sequence 4210, 4211).

  In order to transmit the connection establishment request message to the terminal 1, the control module requests the common key generation module to generate a session key to be shared with the terminal 1 (sequence 4212).

  The common key generation module stores the generated session key in the database (sequences 4213 and 4214), and passes the session key to the control module (sequence 4215).

  The control module requests the message generation module to transmit a connection establishment request message to the terminal 1 (sequence 4216). At this time, the session key with terminal 1, all permission information shares, and the public key of terminal 1 are passed to the message generation module.

  The message generation module generates a message with all permission information shares attached to the content of the connection establishment request, performs a message electronic signature / encryption process, and transmits a connection establishment request message 525 to the terminal 1 through the message processing module.

  In FIG. 38, sequences 4204, 4205, and 4226 correspond to the messages 531 532, and 533 in FIG.

  FIG. 39 is a sequence diagram showing module processing in the terminal 1 when the terminal 1 receives the connection establishment request message 533 transmitted by the terminal 4 in FIG.

  When the message processing module of the terminal 1 receives the message 533, the message decryption process is performed via the message analysis module in order to decrypt the electronic signature and the encrypted message (sequences 4300 to 4315). Then, the decrypted message content and the attached all permission information share and the session key shared with the terminal 4 are passed (sequence 4316).

  The control module knows from the decrypted message content that the terminal 4 requests establishment of a connection with the terminal 1. Since participation / subscription to the community 201 requires the approval of all the terminals, whether or not the terminal 4 has the right to participate / subscribe with the approval of all the terminals is obtained using the all permission information share acquired from the terminal 4 To check.

  The control module passes the permission information share (2-1-2) and the permission information share (2-1-3) to the permission information comparison module among all the permission information shares, and the permission information share (2 -1-1) and permission information (2-1) are used to request that the terminal 4 check whether all the other terminals of the community 201 have the right to join / subscribe to the community 201 (sequence) 4317). At this time, the destination information of the terminal 4 is passed at the same time.

  The permission information comparison module inquires of the database about permission information share (2-1-1) and permission information (2-1) (sequences 4318 and 4319). Then, for the VSS decryption module, the permission information is decrypted from the permission information share (2-1-1), the permission information share (2-1-2), and the permission information share (2-1-3). Request (sequence 4320).

  The VSS decryption module generates permission information (2-1-A) generated by decoding from the three permission information shares, and passes it to the permission information comparison module (sequence 4321).

  The permission information comparison module compares the permission information (2-1) and the permission information (2-1-A) and determines whether there is a difference. If there is a difference, it is regarded as invalid and the connection is not established. If there is no difference, the difference between the time information at the time of comparison and the time information included in the permission information (2-1) is calculated, and it is confirmed that the time has not passed for a certain time. If it has not elapsed, it is determined that the information is normal, and the destination information of the terminal 4 is compared, and whether there is any difference from the destination information of the terminal 4 included in the permission information (2-1).

  When the above comparison ends normally, a normal response is returned to the control module (sequence 4322).

  Next, whether or not the remaining permission information shares (permission information share (2-2-1) and permission information share (2-2-3)) are fraudulent is confirmed using a share verification module.

  The control module inquires of the database for permission information share verification information (2-2) acquired from the terminal 2 (sequences 4323 and 4324). Then, the control module provides the permission information share (2-2-1) and permission information share verification information (2-2) to the share verification module, requests the share verification module to verify fraud, and performs share verification. If the module is not illegal, a normal response is returned to the control module (sequence 4325, 4326).

  Similarly, the fraud of permission information share (2-2-3) is verified (sequence 4327, 4328).

  If the above check is performed and there is no fraud in all permission information shares, it is determined that the terminal 4 has obtained approval from all terminals for participation / subscription in the community 201. Then, the connection establishment request is accepted, and the session key with the terminal 4 is stored in the database (sequences 4329 and 4330). Also, the database is inquired of the connection establishment information share (2-3-1) (sequences 4331 and 4332).

  The control module requests the message generation module to transmit a response message attached with the connection establishment information share (2-3-1) to the terminal 4 (sequence 4333). At this time, the session key shared with the terminal 4 and the connection establishment information share (2-3-1) are passed to the message generation module.

  The message generation module generates a message with the connection establishment information share (2-3-1) attached to the content of the consent to the connection establishment request, performs the message encryption process, and then sends a response message to the terminal 4 through the message processing module. 534 is transmitted (sequences 4334 to 4337).

  After transmitting the response message 534 to the terminal 4, the message processing module of the terminal 1 receives the connection establishment confirmation message 535 from the terminal 4.

  When the message processing module receives the message 535, in order to decrypt the message encrypted with the session key shared with the terminal 4, the message processing module is used to perform the message decryption process (sequence 4338-). 4343). Then, the decrypted message content is passed to the control module (sequence 4344).

  The control module learns from the decrypted message that the connection has been successfully established between the terminal 1 and the terminal 4.

  In FIG. 39, sequences 4300, 4337, and 4338 correspond to messages 533, 534, and 535 in FIG.

  FIG. 40 is a sequence diagram illustrating module processing in the terminal 4 when the terminal 4 receives the response message 534.

  Upon receiving the message 534, the message processing module of the terminal 4 performs a message decryption process via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 1 (sequence 4400). ~ 4405). Then, the decrypted message content and connection establishment information share (2-3-1) are passed to the control module (sequence 4406).

  The control module determines from the decrypted message content that a connection with the terminal 1 can be established. The control module stores the acquired connection establishment information share (2-3-1) in the database (sequences 4407 and 4408), and then transmits a connection establishment confirmation message to the terminal 1 (sequences 4409 to 4413).

  In FIG. 40, sequences 4400 and 4413 correspond to messages 534 and 535 in FIG. 21, respectively.

  FIG. 41 is a sequence diagram showing module processing in the terminal 4 when the terminal 4 transmits a connection establishment request message to the terminal 2 after the terminal 4 establishes a connection with the terminal 1 in FIG. In the second embodiment, the connection is established with the terminal 1 first, but the connection with the terminal 2 is established in some cases.

  41 (sequence 4500-4514) is exactly the same as sequence 4212-4226 in FIG. 38, and the control module of terminal 4 generates a session key shared with terminal 2 and attaches all permission information shares. An establishment request message 536 is transmitted to the terminal 2.

  In FIG. 41, a sequence 4514 corresponds to the message 536 in FIG.

  FIG. 42 is a sequence diagram showing module processing when the terminal 2 receives the connection establishment request message 536 transmitted from the terminal 4 in FIG.

  The process in FIG. 42 (sequences 4600 to 4644) is exactly the same as the process in FIG. 39 (sequences 4300 to 4344), and all permission information shares (permission information share (2-1-2) and permission information acquired from the terminal 4). Share (2-1-3), permission information share (2-2-1), permission information share (2-2-3)), and terminal 4 will participate in joining / subscribing to the community. Terminal 2 attaches the connection establishment information share (2-3-2) to the response message 537 and transmits it to the terminal 4. Then, the terminal 2 receives the connection establishment confirmation message 538 and confirms that the connection has been normally established between the terminal 2 and the terminal 4.

  42, sequences 4600, 4637, and 4638 correspond to messages 536, 537, and 538 in FIG. 21, respectively.

  FIG. 43 is a sequence diagram illustrating module processing in the terminal 4 when the terminal 4 receives the response message 537.

  43 (sequences 4700 to 4713) is the same as the process (sequences 4400 to 4413) of FIG. 40, and the terminal 4 acquires the connection establishment information share (2-3-2) from the terminal 2 and confirms the connection establishment. A message 538 is transmitted to the terminal 2.

  In FIG. 43, sequences 4700 and 4713 correspond to messages 537 and 538 in FIG.

  FIG. 44 is a sequence diagram illustrating module processing in the terminal 4 when the terminal 4 transmits a community establishment / subscription acceptance message 539 to the terminal 3 after the terminal 4 transmits the connection establishment confirmation message 538 to the terminal 2.

  The control module of the terminal 4 inquires of the database about the session key shared with the terminal 3, the connection establishment information share (2-3-1), and the connection establishment information share (2-3-2) (sequences 4800 and 4801). . Then, the session key shared with the terminal 3, the connection establishment information share (2-3-1), and the connection establishment information share (2-3-2) are passed to the message generation module, and a community participation / subscription acceptance message is transmitted. (Sequence 4802).

  The message generation module generates a message with the connection establishment information share (2-3-1) and connection establishment information share (2-3-2) attached to the contents of community participation / subscription acceptance, and performs the message encryption process. Thereafter, a community participation / subscription acceptance message 539 is transmitted to the terminal 3 through the message processing module (sequences 4803 to 4806).

  In FIG. 44, a sequence 4506 corresponds to the message 539 in FIG.

  FIG. 45 is a sequence diagram showing module processing in the terminal 3 when the terminal 3 receives the community participation / subscription acceptance message 539.

  When the message processing module of the terminal 3 receives the message 539, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 4 (sequence 4900). ~ 4905). Then, the decrypted message content, the connection establishment information share (2-3-1) and the connection establishment information share (2-3-2) attached are passed to the control module (sequence 4906).

  The control module knows from the decrypted message content that the terminal 4 has accepted the participation / subscription into the community 201. Obtained from the terminal 4 because the connection with all member terminals (terminal 1 and terminal 2) participating in and joining the community 201 other than the terminal 3 must be established in order to establish a connection with the terminal 4. The connection establishment status of the terminal 4 is checked using the connection establishment information share (2-3-1) and the connection establishment information share (2-3-2).

  The control module provides the connection establishment information comparison module to the connection establishment information share (2-3-1) and the connection establishment information share (2-3-2), and the terminal 4 establishes a connection with the terminal 1 and the terminal 2. It is requested to check whether or not this is done (sequence 4907).

  The connection establishment information comparison module inquires the connection establishment information share (2-3-3) and connection establishment information (2-3) to the database (sequences 4908 and 4909). Then, the connection establishment information share (2-3-1), the connection establishment information share (2-3-2), and the connection establishment information share (2-3-3) are provided to the VSS decryption module and decrypted. (Sequence 4910).

  The VSS decoding module restores the connection establishment information (2-3-A) from the three connection establishment information shares and returns it to the connection establishment information comparison module (sequence 4911).

  The connection establishment information comparison module compares the connection establishment information (2-3-A) with the connection establishment information (2-3) and checks whether there is a difference. If there is a difference, it is determined that the access of the terminal 4 is illegal. If there is no difference, the difference between the time information at the time of comparison and the time information included in the connection establishment information is calculated, and it is checked whether or not a certain time has elapsed.

  If the above processing ends normally, the connection establishment information comparison module returns a normal response to the control module (sequence 4912).

  When the connection check using the connection establishment information share ends normally, the control module of the terminal 3 accepts the connection establishment. Then, the control module requests the message generation module to transmit a connection establishment confirmation message (sequence 4913). At this time, the session key sharing the terminal 4 is passed to the message generation module.

  The message generation module generates the contents of the connection establishment confirmation as a message, performs a message encryption process, and transmits a connection establishment confirmation message 540 to the terminal 4 through the message processing module (sequences 4914 to 4917).

  45, the sequence 4900 corresponds to the message 539 in FIG. 21, and the sequence 4917 corresponds to the message 540 in FIG.

  FIG. 46 shows module processing in the terminal 4 when the terminal 4 receives the connection establishment confirmation message 540.

  When the message processing module of the terminal 4 receives the message 540, the message decryption process is performed via the message analysis module in order to decrypt the message encrypted with the session key shared with the terminal 3 (sequence). 5000 to 5005). Then, the decrypted message content is passed to the control module (sequence 5006).

  The control module knows from the decrypted message content that the connection with the terminal 3 has been successfully established.

  In FIG. 46, the sequence 5000 corresponds to the message 540 in FIG.

  As described above, each member terminal (terminal 1 and terminal 2) uses a permission information share as voting information, a voting information providing message, or a primary or negative for the participation / subscription of a new terminal (terminal 4) to the community. Prepare for voting by distributing with decision-making messages, and each member terminal (total number of terminals participating in / subscribing to the community -2) share the permitted information share with the vote of approval, the final decision message of approval or disapproval By voting by submitting to the receiving terminal (terminal 3), even if there is no existence that centrally manages access rights to the community depending on whether or not all member terminals submit the approval vote, the full mesh network Thus, each terminal can surely confirm the intention (whether or not) of all terminals with respect to participation / subscription of a new terminal in the community.

  In addition, each member terminal does not depend on the other member terminals, and by independently generating permission information including any random keyword, the other member terminals guess the permission information and illegally generate it. Generating permission information shares, for example, behaves as if all devices were in favor of joining or joining a new device community, even though no other device had submitted a vote If each member terminal receives a connection establishment request message from the new terminal, whether or not the new terminal has gained approval from joining or joining the community from all other terminals except the own terminal, Share of permission information generated from the own terminal's permission information and distributed to each member terminal (the total number of terminals belonging to the community) and permission information in the own terminal's database A permission information restored by VSS through shares, the processing of comparing the authorization information in the database of the terminal, each member terminal without being rigged to another terminal can be checked independently correctly.

  In addition, when each member terminal receives a connection establishment request message from the new terminal, the member terminal does not only perform the comparison process of the permission information using the permission information share distributed by the own terminal, Whether or not there is any fraud in the permission information share of (number of all terminals participating / subscribing to the community-1) × (total number of terminals participating / subscribing to the community-2) distributed by the member terminals of Verification is performed by using permission information share verification information and a share verification module acquired in advance from other member terminals when distributing the permission information share.

  As a result, the process in which each other member terminal submits the permission information share as an approval vote to the receiving terminal (final decision message of approval or disapproval), the permission information share collected from each member terminal and the permission information of the own terminal In the process of providing shares to new terminals (community invitation messages), for example, it is possible to detect fraud, such as submitting only some permission information shares without submitting all permission information shares. In the comparison process of permission information, when it is determined that the new terminal is in favor of joining or joining the community, the new terminal can always establish a connection with other member terminals other than its own terminal. A situation can be created, and the new terminal can participate in the community in the comparison process of the permission information performed on its own terminal. - when it is determined not to give the approval to the subscriber can create a situation that can not be new terminal establishes a sure connection with another member terminal other than the terminal itself. As a result, the new terminal cannot establish a connection with a terminal other than its own terminal even though it is determined that it is in favor. Alternatively, it is possible to prevent a situation in which a new terminal can establish a connection with a terminal other than its own terminal even though it is determined that it is not in favor.

  Further, in the second embodiment, each member terminal performs distributed encoding of permission information with a threshold (3, 3), and one of the obtained three permission information shares is always stored in its own terminal, Further, since the permission information is also stored in the own terminal and is not leaked to other terminals at all, it is possible to prevent other terminals from guessing the permission information.

  In the second embodiment, each member terminal performs distributed encoding of permission information with a threshold value (3, 3), and if the receiving terminal and all member terminals do not agree (that is, all distributed permission information shares are distributed). The new terminal cannot establish a connection with each member terminal, but the required vote can be changed freely by changing the threshold value for distributed encoding. For example, If the threshold k (k ≦ 3) is set, if k approval votes (permission information share) are collected from three terminals, a new terminal can establish a connection with a terminal belonging to the community. It is possible to freely set the number of votes required for.

  In addition, the permission information share provided to the new terminal is not provided as it is, but it is intercepted by a terminal other than the new terminal by providing it as a permission ticket encrypted with the public key of the new terminal including the destination information. In addition, it is possible to notify the new terminal of destination information of all the terminals participating / subscribing to the community using the permission ticket.

  In addition, each member terminal does not provide the permission information share, which is voting information, directly and independently to the new terminal. It becomes possible to handle the permission information share required when making a connection establishment request to the member terminals in a unified manner. Thus, simultaneous access that may occur by each member terminal accessing the new terminal in order to directly provide the permission information share to the new terminal can be prevented.

  Also, by setting the time information in the permission information, it is possible to set an expiration date until the new terminal establishes a connection with each member terminal, improving the security level, and in the permission information comparison module, An arbitrary security level can be set by freely setting a reference effective time.

  In addition, in order to check whether the member terminal has established a connection with the new terminal, in the second embodiment, the receiving terminal is distributed and encoded with connection establishment information and threshold values (3, 3). After each member terminal submits an approval information share that is a vote of approval, the receiving terminal distributes two connection establishment information shares to each member terminal one by one. When establishing a connection with a new terminal, the connection establishment information share acquired from the receiving terminal in advance is passed to the new terminal, and then acquired from each member terminal when the new terminal establishes a connection with the receiving terminal. Pass the connection establishment information shares to the receiving terminal, and the receiving terminal shares the two connection establishment information shares, Connection establishment information share managed by the database and a VSS decoding module are used to restore the connection establishment information, and the restored connection information is compared with the connection establishment information managed by the database inside the receiving terminal. Thus, the receiving terminal can check whether the new terminal has established a connection with all member terminals, and creates a situation in which a connection with all the terminals must be established when establishing a connection with the receiving terminal. It becomes possible.

  In addition, by setting time information in the connection establishment information, it is possible to set an expiration date until the new terminal establishes a connection with the receiving terminal, thereby improving the security level and comparing the connection establishment information. In the module, it is possible to set an arbitrary security level by freely setting a reference effective time.

  Further, in the case of the second embodiment, the receiving terminal does not provide the member terminal with the destination information of the new terminal that is invited to the community or wants to join or join as it is. ) By providing the member terminal with destination information share obtained by performing distributed encoding using VSS and destination information share verification information for detecting fraud of the destination information share. Share fraud can be verified using the destination information share verification information and the share verification module, and the address information of the original new terminal cannot be restored unless all member terminals belonging to the community except the receiving terminal cooperate. Therefore, it is possible to prevent fraud such that the receiving terminal presents different destination information for each member terminal.

  In addition, each member terminal checks the permission information share obtained from all member terminals other than its own terminal using the permission information share verification information and the share verification module before submitting the approval vote. It is possible to submit a correct approval vote without any error to the receiving terminal and at the same time detect fraud at the time of submission.

  In the second embodiment, the total number of terminals belonging to the community is three (terminal 1, terminal 2, terminal 3), but the same effect can be obtained even when the number is four or more.

  In addition, messages exchanged between terminals must be digitally signed and encrypted, or encrypted with a session key after authenticating with a digital signature, so that various information exchanged by each terminal (permission information share, permission information share) (Verification information, destination information, destination information share, destination information share verification information, connection establishment information, connection establishment information share) can be prevented from being intercepted by a third party.

  Also, any type of information can be applied to the destination information, for example, an IP address or a SIP address can be applied.

  In addition, according to the embodiment of the present invention described above, when a new entity joins or joins a community based on a full mesh network, access control based on approval / disapproval votes by a plurality of entities already joining the community is realized. Can detect unauthorized entities present in the authorization decision process, prevent unauthorized manipulation of the authorization decision process, and for each entity that a new entity has already joined or joined the community When establishing a connection, the authorization decision process can be performed safely and without fraud, ensuring that other entities that have joined or joined the community have agreed (allowed) the new entity to join or join the community. Communication system that can be confirmed , It is possible to provide a communication method and a program.

  Note that the configuration described in the embodiment of the present invention described above communicates with a plurality of terminals or public key servers connected to the network, and establishes connections to the plurality of terminals to establish a community. Is a communication system for obtaining a public key by a public key acquisition request to a public key server, and a full mesh network formed by a full mesh connection between two or more terminals. A request is made to invite a formed community and a new terminal that does not belong to the community to the community, or a terminal that belongs to the community that has received a request that a new terminal that does not belong to the community belongs to the community. For a service terminal composed of one of them and a community other than the service terminal Information that serves as a basis for creating voting information for deciding whether to participate or join when a new terminal joins or joins a community terminal. To generate permission information that is information for confirming whether or not the new terminal has obtained approval for participation / subscription from the community member terminal and the service terminal when each member terminal is requested to establish a connection. The permission information generation module, the connection establishment information generation module that generates the connection establishment information necessary for the receiving terminal to check whether the new terminal has established a connection with the member terminal, and the member terminal independently generated The permission information is distributed and coded by the (k, n) threshold method (k ≦ n) of the verifiable secret sharing, N pieces of permission information share and one piece of permission information share verification information that is information for voting are generated, and connection establishment information is similarly distributed by the secret sharing method (k, n) threshold method (k ≦ n). , Generate n connection establishment information shares, and similarly verify destination information of new terminals when the total number of terminals participating / subscribing in the community is 3 or more (k, n) threshold method of secret sharing (K ≦ n), and a VSS distributed encoding module for generating n destination information shares and one destination information share verification information, and a secret sharing method or verifiable secret sharing (k, n) VSS decoding module for restoring original information by using k or more shares from n distributed coded shares by threshold method, permission information share verification information and destination information share Validation A share verification module that checks whether the permission information share, the connection establishment information share, and the destination information share are illegal by using VSS, and a common key generation module that generates a session key by a common key encryption method. And the permission information generated by the permission information generation module, the permission information share generated using the VSS distributed encoding module and the permission information, the permission information share verification information, and the connection establishment information generation module The connection establishment information to be generated, the connection establishment information share to be generated by using the VSS distributed coding module and the connection establishment information, the session key to be generated by the common key generation module, and the public key server The public key of the terminal other than the terminal and the private key of your terminal And public key, destination information of other terminals, VSS distributed coding module and destination information share generated using destination information, destination information share verification information, and all participating / subscribed in the community A database that manages a list of all terminals, and whether the new terminal is favored by another terminal that belongs to the community when the new terminal requests each member terminal to establish a connection The permission information share acquired from the new terminal, the permission information share managed by the database of the own terminal, the permission information restored using the VSS decryption module, and the permission information managed by the database of the own terminal The permission information comparison module for comparing and confirming the Establishing a connection with a host terminal by using the connection establishment information share acquired from the new terminal, the connection establishment information share managed by the local terminal database, and the VSS decryption module Connection establishment information comparison module for comparing and confirming information and connection establishment information managed in its own database, and disclosure for encrypting the information requested for encryption using the public key encryption method The key encryption method encryption module, the common key encryption method encryption module for encrypting the information requested for encryption by the common key encryption method, and the conversion results of multiple information must be the same Digest of arbitrary information using a message digest function, which is a kind of hash function that is difficult A digest generation module for generating, a public key encryption scheme decryption module for decrypting information received by the decryption request by a public key encryption scheme, and a common key for the information received by the decryption request Common key encryption method decryption module for decryption by encryption method, determination of whether or not to establish a connection, primary determination of approval or disapproval for participation / subscription of a new terminal to the community, and new terminal to the community A decision input module for making a final decision on whether or not to participate / subscribe and whether or not to join / subscribe to the community, and a message with the requested content. When attaching the information passed at the time of request to the message, if you want to digitally sign and encrypt the message, use public key encryption. A message encryption module, a common key cryptography module, and a digest generation module to execute attachment, and when only encryption is performed, a message generation module for executing attachment with the common key cryptography module, and permission information Request to the permission information generation module, request the connection establishment information generation module to generate the connection establishment information, permit information share, permission information share verification information, connection establishment information share, or destination information share And the destination information share verification information are requested to the VSS distributed encoding module, and encryption with the public key of the permission information share is requested to the public key cryptosystem encryption module, and the encrypted permission Ask the public key cryptosystem decryption module to decrypt the information share, Asks the input module to make a decision, asks the VSS decryption module to restore the destination information from the destination information share, asks the permission information comparison module to compare the permission information, and compares the connection establishment information. Request the connection establishment information comparison module, request the common key generation module to generate the session key, request the share verification module to check whether the permission information share or the destination information share is illegal, A control module for saving and requesting the message generation module to generate a message, and for all terminals, to confirm whether fraudulent activity has been performed during transmission / reception of received messages. Digest from the included digest and the content of the message Message fraud determination module for comparing whether or not there is a difference in the digests generated by the st generation module, and if all received messages are digitally signed and encrypted Control module in the case where the message is decrypted with the key encryption system decryption module and the common key encryption system decryption module, and the public key of the source terminal necessary for decrypting the message is not stored in the database. Requesting the public key server to obtain a public key through the digest, and confirming whether the message is fraudulent after the decryption process, and digesting the message content and the message content from the digest. The digest is generated by the generation module and two digests are generated. The message is sent to the message fraud determination module and a request is made to check for fraud. If there is no fraud, the message content is passed to the control module. On the other hand, if the message is only encrypted, the common key cipher The message decryption module decrypts the message and passes the content of the decrypted message to the control module, and the message generated by the message generation module is sent to an external terminal or public key server. A message processing module for transmitting and passing a message received from an external terminal or public key server to the message analysis module.

  Further, the permission information generating module generates and generates permission information by time information at the time of generation, destination information of the new terminal, and an arbitrary random keyword.

  The connection establishment information generation module generates and generates connection establishment information by time information at the time of generation, destination information of a new terminal, and an arbitrary random keyword.

  In the case where the total number of terminals is two, the receiving terminal asks the member terminal whether or not to join or join the new terminal community, and the member terminal distributes the VSS based on the permission information generated independently. The encoding module generates three permission information shares as voting information with threshold values (3, 3), one of which is distributed to the receiving terminal, and the member terminal agrees with the first stage. Member terminal submits one permission information share of its own terminal to the receiving terminal as an approval vote, and decides whether to join or join the new terminal to the community. If the terminal approves, the new terminal communicates two permission information shares, one of which is collected by the receiving terminal as a vote of approval from the member terminal and one of the receiving terminal. First, a new terminal establishes a connection with a member terminal and attaches all permission information shares acquired from the receiving terminal to a message for requesting connection establishment. If the total number of terminals is three or more, the receiving terminal asks all member terminals whether or not to join or join a new terminal community, and each member terminal is independent. Based on the generated permission information, the VSS distributed coding module uses (permitted number of terminals), (total number of terminals)) (permitted number of terminals) permission information share, permission information share verification information, Of the total number of terminals, and distributes the permission information share of (total number of terminals −1) to each of the other member terminals and the receiving terminals one by one. After the verification information is distributed, the first stage is set, and when all the member terminals agree in the first stage, each member terminal is obtained from all the other member terminals (total number of terminals -2). The second stage is to decide whether to join or join a new terminal to the community by submitting each share of permission information as an approval vote to the receiving terminal. In the second stage, all member terminals are in favor. In this case, (the total number of terminals−2) × (the total number of terminals−1) pieces and the (total number of terminals−1) pieces possessed by the receiving terminals are collected as approval votes from all the member terminals. , (Total number of terminals-1) x (total number of terminals-1) permission information share is provided as a ticket to join / join the community to the new terminal, and the new terminal establishes a connection with each member terminal From the receiving terminal. The third stage attached to the message establishes requirements for all authorized information share a connection to.

  Further, in the first stage, when each member terminal distributes the permission information share, when the total number of terminals is two, the member terminal can use one of the three permission information shares generated by the own terminal. Distribute to the receiving terminal, and one is a vote for own terminal, and the remaining one permission information share is managed without leaking to other terminals. When the total number of terminals is three or more, each member terminal Is distributed among other terminals out of (total number of terminals) permission information shares generated by the terminal itself, and the remaining one permission information share and permission information are each other terminals To manage without leaking.

  In addition, when the member terminal submits permission information share to the receiving terminal, or when the receiving terminal provides the permission information share acquired from each member terminal to the new terminal, the new terminal including the destination information of the own terminal The public key is used to encrypt and submit using the public key cryptosystem encryption module.

  Further, in the second stage, when all member terminals have submitted a vote for the response terminal, the response terminal generates connection establishment information by the connection establishment information generation module, and the connection establishment information is obtained by the VSS distributed encoding module. Of the connection information shares of (total number of terminals) obtained by distributed coding with threshold values ((total number of terminals), (total number of terminals)), (total number of terminals minus 1) is set to one for all member terminals. It is provided one by one, and the remaining one connection establishment information share and the connection establishment information that is the original information are managed by the database without leakage to the outside.

  In addition, when a member terminal receives a message indicating a connection establishment request with a permission information share attached from a new terminal, the member terminal receives approval for participation / subscription from all terminals belonging to a community other than its own terminal. The permission information comparison module receives a request for comparison of permission information from the control module. If the total number of terminals is two, two permission information shares attached to the connection establishment request message are received. Then, using one permission information share managed in the own terminal database, the permission information is restored by the VSS decryption module and compared with the permission information stored in the own terminal database. If there is no difference, the difference between the time information included in the permission information and the time information at the time of comparison is set in advance. If it is less than the predetermined value, further check whether the destination information is different from the new terminal. If there is no difference, return a normal response to the control module, and the total number of terminals. Is 3 or more (total number of terminals −1) × (total number of terminals −1) permission information shares attached to the connection establishment request message (the total number of terminals− 1) Using one permission information share and one permission information share managed in the own terminal database, the permission information is restored by the VSS decoding module and saved in the own terminal database. If there is no difference, it is checked whether the difference between the time information included in the permission information and the time information at the time of comparison is greater than or equal to a predetermined value. If the destination information is new terminal If there is no difference, whether the remaining (total number of terminals−2) × (total number of terminals−1) pieces of permission information share is illegal or not is determined with the share verification module. Confirmation is performed using permission information share verification information acquired at the time of permission information share distribution from other member terminals, and if there is no fraud, a normal response is returned to the control module.

  In addition, a permission information validity period setting unit for arbitrarily setting a predetermined value indicating the validity period of the permission information is provided.

  In addition, when a new terminal transmits a message indicating a connection establishment request to each member terminal and the connection is normally established, each member terminal shares the connection establishment information share stored in the database by itself. The new terminal is provided to the receiving terminal including the connection establishment information share (total number of terminals −1) acquired from all the member terminals, and the new terminal establishes connections with all the member terminals. In order to confirm whether or not the connection establishment information comparison module has received a request for comparison of connection establishment information from the control module, the connection establishment information shares of (total number of terminals-1) pieces of connection establishment information acquired from the new terminal, One connection establishment information share managed in the database of its own terminal, a VSS decryption module, The connection establishment information restored by use and the connection establishment information managed in the database of the own terminal are compared to check whether there is a difference. If there is no difference, it is included in the connection establishment information. It is checked whether or not the difference between the time information and the time information at the time of comparison is equal to or greater than a predetermined value. If the difference is equal to or smaller than the predetermined value, a normal response is returned to the control module.

  In addition, a connection establishment information validity period setting unit is provided for arbitrarily setting a predetermined value indicating the validity period of the connection establishment information.

  In addition, when the receiving terminal asks each member terminal whether or not to participate / subscribe to the community of the new terminal, the new terminal that is desired to invite or participate / subscribe is notified to the member terminal as destination information, and all terminals When the number is three or more, the destination information share obtained by distributedly encoding the destination information of the new terminal by the VSS distributed encoding module and the information for verifying the destination information share are notified, and each member terminal communicates with the original destination To obtain information, exchange the destination information shares acquired from the receiving terminal with each other, verify the fraud of all destination information shares with the destination information share verification information and the share verification module acquired from the receiving terminal, and then VSS The original destination information is restored by the decryption module.

  In addition, when the member terminal submits the permission information share as an approval vote, the share verification module checks whether each permission information share is illegal by the permission information share verification information.

  Also, in the first stage, whether or not the receiving terminal can proceed to the second stage for voting in response to a request for approval or disapproval for participation / subscription of the new terminal to the community notified from all member terminals. In the second stage, the voting result is notified.

It is explanatory drawing which shows the structure of the network based on 1st Embodiment of the communication system of this invention. It is explanatory drawing which shows the example of the internal module structure in the terminal 1 to the terminal 4 based on 1st Embodiment of the communication system of this invention. It is explanatory drawing which shows the example of the message exchanged when establishing a one-to-one connection between the terminal 1 and the terminal 2 based on 1st Embodiment of the communication system of this invention. It is explanatory drawing which shows the process between modules in the terminal 1 when establishing a connection between the terminal 1 and the terminal 2 on the one-to-one basis based on 1st Embodiment of the communication system of this invention. It is explanatory drawing which shows the process between modules in the terminal 2 when establishing a connection between the terminal 1 and the terminal 2 on the one-to-one basis based on 1st Embodiment of the communication system of this invention. According to the first embodiment of the communication system of the present invention, each time a terminal 3 is newly invited to a community from a state where a connection has already been established between the terminal 1 and the terminal 2 and a community has been formed. It is explanatory drawing which shows the message exchanged between terminals. It is a sequence diagram which shows the module process in the terminal 1 until the terminal 1 transmits the message 402 with respect to the messages 400 and 401 and the terminal 2 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 2 until the terminal 2 receives the message 402 from the terminal 1 and transmits 403, 404 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the process between the modules in the terminal 1 when the terminal 1 receives the message 405 from the terminal 2 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 2 until the terminal 2 receives the message 406 and transmits the message 407 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 2 until the terminal 2 transmits the message 408 to the terminal 1 and receives the message 409 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 1 when the terminal 1 receives the message 408 from the terminal 2 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 1 when the terminal 1 after the process of FIG. 12 transmits the message 412 with respect to the terminal 3 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 3 when the terminal 3 receives the message 412 from the terminal 1 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 3 until the terminal 3 transmits the message 417 to the terminal 2 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 2 when the terminal 2 receives the message 417 from the terminal 3 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 3 when the terminal 3 receives the message 418 from the terminal 2, and returns the message 419 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 3 when the terminal 3 transmits the message 420 to the terminal 1 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 1 when the terminal 1 receives the message 420 from the terminal 3 based on 1st Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 3 when the terminal 3 receives the message 421 from the terminal 1 based on 1st Embodiment of the communication system of this invention. According to the second embodiment of the communication system of the present invention, the terminal 4 is newly connected to the community from the state where the connection is established in the full mesh between the terminal 1, the terminal 2 and the terminal 3, and the community is formed. It is explanatory drawing which shows the message exchanged between each terminal when inviting to. According to the second embodiment of the communication system of the present invention, the terminal 3 transmits the message 500 to the public key server 5, receives the message 501 from the public key server, and further sends the message 502 to the terminal 1 and the terminal 2 to the terminal 2. FIG. 5 is a sequence diagram showing module processing in the terminal 3 until a message 503 is transmitted. It is a sequence diagram which shows the module process in the terminal 1 until the terminal 1 receives the message 502 from the terminal 3, and transmits the message 504 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 2 when the terminal 2 receives the message 504 from the terminal 1 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 1 when the terminal 1 receives the message 505 based on 2nd Embodiment of the communication system of this invention. A sequence showing module processing in the terminal 1 until the terminal 1 transmits the message 513 to the terminal 2 and the message 515 to the terminal 3 after the sequence of FIG. 25 according to the second embodiment of the communication system of the present invention. FIG. 24 is a sequence showing module processing in the terminal 2 until the terminal 2 transmits the message 508 to the terminal 1 and the message 510 to the terminal 3 after the sequence of FIG. 24 according to the second embodiment of the communication system of the present invention. FIG. It is a sequence diagram which shows the module process in the terminal 1 when the terminal 1 receives the message 514 from the terminal 2 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 2 when the terminal 2 receives the message 509 from the terminal 1 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 3 when the terminal 3 receives the message 515 from the terminal 1, and the message 510 from the terminal 2 based on 2nd Embodiment of the communication system of this invention. According to the second embodiment of the communication system of the present invention, the module processing in the terminal 3 until the terminal 3 transmits messages 516 and 518 to the terminals 1 and 2 and receives the response messages 517 and 519, respectively. FIG. The sequence which shows the module process in the terminal 1 until the terminal 1 transmits the message 520 to the terminal 3, and transmits 525 after receiving the messages 521 and 524 based on 2nd Embodiment of the communication system of this invention FIG. The sequence which shows the module process in the terminal 2 until the terminal 2 transmits the message 522 to the terminal 3 and receives 527 after receiving the messages 523 and 526 according to the second embodiment of the communication system of the present invention FIG. In the terminal 3 until the terminal 3 receives the message 520 from the terminal 1, returns the message 521, receives the message 522 from the terminal 2, and returns the message 523, according to the second embodiment of the communication system of the present invention. It is a sequence diagram which shows the module process of. It is a sequence diagram which shows the module process in the terminal 3 when the terminal 3 transmits the message 524,526 to the terminal 1 and the terminal 2 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 3 until the terminal 3 transmits the message 528 to the terminal 4 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 4 when the terminal 4 receives the message 528 from the terminal 3 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 4 until the terminal 4 transmits the message 533 to the terminal 1 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 1 when the terminal 1 receives the message 533 from the terminal 4 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 4 when the terminal 4 receives the message 534 from the terminal 1 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 4 until the terminal 4 transmits the message 536 to the terminal 2 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 2 when the terminal 2 receives the message 536 from the terminal 4 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 4 when the terminal 4 receives the message 537 from the terminal 2 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 4 until the terminal 4 transmits the message 539 to the terminal 3 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 3 when the terminal 3 receives the message 539 from the terminal 4 based on 2nd Embodiment of the communication system of this invention. It is a sequence diagram which shows the module process in the terminal 4 when the terminal 4 receives the message 540 from the terminal 3 based on 2nd Embodiment of the communication system of this invention.

Explanation of symbols

1, 2, 3, 4, 6 terminal 5 public key server 10, 11, 12 connection 100 network 111 intention input module 112 permission information generation module 113 permission information comparison module 114 connection establishment information generation module 115 connection establishment information comparison module 116 VSS Distributed encoding module 117 VSS decryption module 118 Common key generation module 119 Common key encryption system encryption module 120 Common key encryption system decryption module 121 Public key encryption system encryption module 122 Public key encryption system decryption module 123 digest generation module 124 Message fraud determination module 125 Database 126 Message generation module 127 Message processing module 128 Message analysis module Joule 129 Share Verification Module

Claims (42)

Communicates with a plurality of terminals or public key servers connected to the network, forms a community by establishing connections with the plurality of terminals, and public keys with respect to the public key server A communication system for acquiring a public key in response to an acquisition request,
The community formed by a full mesh network formed by a full mesh connection between two or more of the terminals;
Either a request is made to invite a new terminal not belonging to the community to the community, or a terminal belonging to the community has received a request that a new terminal not belonging to the community belongs to the community A reception terminal composed of
Member terminals composed of terminals belonging to the community other than the reception terminal;
When joining or joining a new terminal to the community, this is information that serves as a basis for creating voting information for deciding whether to participate or join, and the new terminal is connected to each of the member terminals. When requesting establishment, permission information for generating permission information that is information for confirming whether or not the new terminal obtains approval for the participation / subscription from the member terminal and the reception terminal of the community Generation module,
A connection establishment information generation module for generating connection establishment information necessary for the reception terminal to confirm whether or not a new terminal has established the connection with the member terminal;
The permission information generated independently by each member terminal is distributedly encoded by the verifiable secret sharing (k, n) threshold method (k ≦ n), and the n permission information shares and one permission that are voting information are obtained. Information share verification information is generated, and connection establishment information is similarly distributedly encoded by the secret sharing method (k, n) threshold method (k ≦ n) to generate n connection establishment information shares. When the total number of terminals participating / joining the community is 3 or more, the destination information of the new terminal is distributedly encoded by the verifiable secret sharing (k, n) threshold method (k ≦ n), and n destinations VSS distributed encoding module for generating information share and one destination information share verification information;
VSS decoding for restoring original information by using k or more shares from n distributed coded shares by the secret sharing method or the verifiable secret sharing (k, n) threshold method Module
A share verification module that uses the permission information share verification information and the destination information share verification information to check whether the permission information share, the connection establishment information share, and the destination information share are illegal by VSS,
A common key generation module for generating a session key by a common key encryption method;
Have
The permission information generated by the permission information generation module, the permission information share generated using the VSS distributed coding module and the permission information, the permission information share verification information, and the connection establishment information generation Connection establishment information generated by the module, the connection establishment information share generated using the VSS distributed encoding module and the connection establishment information, a session key generated by the common key generation module, and the public key server Using the public key of the other terminal other than the own terminal obtained by making an inquiry to the terminal, the private key and public key of the own terminal, the destination information of the other terminal, the VSS distributed encoding module, and the destination information. The destination information share to be generated, the destination information share verification information, and the community - a terminal a complete list of all of the terminals that have subscribed, and the database to manage,
When the new terminal requests each of the member terminals to establish the connection, the member terminal acquires from the new terminal whether or not the new terminal has received the approval from another terminal belonging to the community. The permission information share managed by the database of the own terminal, the permission information restored using the VSS decryption module, the permission information managed by the database of the own terminal, Permission information comparison module for comparing and confirming,
When the receiving terminal receives access from the new terminal, the connection establishment information share acquired from the new terminal and whether or not the connection has been established with all the member terminals are stored in the database of the own terminal. Connection establishment for comparing and confirming the connection establishment information restored using the connection establishment information share to be managed and the VSS decryption module, and the connection establishment information managed in the database of the own terminal An information comparison module;
A public key encryption scheme encryption module for encrypting information requested for encryption by a public key encryption scheme;
A common key encryption method encryption module for encrypting information requested for encryption by a common key encryption method;
A digest generating module for generating a digest of arbitrary information using a message digest function which is a kind of hash function in which conversion results of a plurality of information are difficult to be the same;
A public key encryption scheme decryption module for decrypting information requested for decryption by a public key encryption scheme;
A common key encryption method decryption module for decrypting information requested for decryption by a common key encryption method;
Determining whether or not to establish the connection, primary determination of approval / disapproval for participation / subscription of the new terminal to the community, final determination of approval / disapproval for participation / subscription of the new terminal to the community, and A decision input module for making a decision on whether to join or join,
When a message having the requested content is generated and the information passed at the time of requesting the generation of the message is attached to the message, when the electronic signature and encryption are applied to the message, the public key encryption method is used. A message generation module for executing the attachment with the common key cryptography module, when performing the attachment with the module, the common key cryptography module, and the digest generating module; ,
The permission information generation module is requested to generate the permission information, the connection establishment information generation is requested to the connection establishment information generation module, the permission information share and the permission information share verification information, or the connection The VSS distributed encoding module is requested to generate the establishment information share or the destination information share and the destination information share verification information, and the public key of the permission information share is encrypted with the public key. Requesting the encryption scheme encryption module, requesting the public key encryption scheme decryption module to decrypt the encrypted permission information share, requesting the intention input module to make the decision, and sending the destination information Ask the VSS decryption module to restore the destination information from the share, and Request comparison to the permission information comparison module, request comparison of the connection establishment information to the connection establishment information comparison module, request generation of the session key to the common key generation module, and request permission to the share verification module. A control module for requesting fraud check of information share or destination information share, inquiring and storing various information in the database, and requesting the message generation module to generate the message;
Generated by the digest generation module from the digest included in the message and the content of the message to confirm whether or not fraudulent activity has been performed during transmission / reception of the received message for all terminals. A message fraud determination module for comparing whether there is a difference between the digests,
For all terminals, when the received message is digitally signed and encrypted, the public key encryption method decryption module and the common key encryption method decryption module are used to decrypt the message. Furthermore, when the database does not have the public key of the source terminal required for decrypting the message, the public key server is requested to acquire the public key through the control module, and decryption processing is performed. In order to confirm whether the message is not cheated later, the digest generation module generates a digest from the message content and digest obtained from the message content, and the two digests are Passed to the message fraud determination module If there is no fraud, the message content is passed to the control module. On the other hand, if the message is only encrypted, the message is decrypted by the common key encryption method decryption module. A message analysis module for passing the content of the message after decryption to the control module;
A message processing module for transmitting the message generated by the message generation module to an external terminal or the public key server, and passing the message received from the external terminal or public key server to the message analysis module; ,
A communication system characterized by comprising: The permission information generation module includes:
The communication system according to claim 1, wherein the permission information is configured and generated by time information at the time of generation, the destination information of the new terminal, and an arbitrary random keyword. The connection establishment information generation module
The said connection establishment information is comprised and produced | generated by the time information at the time of production | generation, the said destination information of the said new terminal, and arbitrary random keywords, The generation | occurrence | production of Claim 1 or 2 characterized by the above-mentioned. Communication system. When the total number of terminals is 2,
The reception terminal asks the member terminal whether or not the new terminal participates in or joins the community, and the member terminal uses the VSS distributed coding module based on the permission information generated independently in the case of approval. A first stage of generating three permission information shares, which are voting information, with a threshold (3, 3), and distributing one of them to the receiving terminal;
When the member terminal approves in the first stage, the member terminal submits one permission information share of its own terminal to the receiving terminal as an approval vote, and joins the new terminal to the community. A second stage of deciding whether to join,
In the second stage, when the member terminal is in favor, the permission is obtained by combining the one collected by the receiving terminal as a vote of approval from the member terminal and the one held by the receiving terminal. Providing an information share as a ticket for joining / subscribing to the community to the new terminal, and when the new terminal establishes the connection with the member terminal, all the permitted information shares acquired from the corresponding terminal A third step of attaching to a message for requesting establishment of the connection,
Alternatively, if the total number of terminals is 3 or more,
The receiving terminal asks all the member terminals whether or not the new terminal participates in or joins the community, and each of the member terminals uses the VSS distributed coding module based on the permission information generated independently. ((Total number of terminals), (total number of terminals)) (total number of terminals) pieces of the permission information share and one piece of permission information share verification information are generated, and (total number of terminals) pieces First, after the distribution of the permission information share verification information is distributed to all the other member terminals and the receiving terminal one by one (total number of terminals −1) of the permission information shares. Stage and
When all the member terminals agree in the first step, each of the member terminals agrees with the permission information share of (total number of terminals−2) obtained from all the other member terminals. As a second step to determine whether to join the new terminal to the community by submitting to the receiving terminal as
When all the member terminals are in favor in the second stage, the receiving terminal collects as a vote of favor from all the member terminals (total number of terminals−2) × (total number of terminals−1) Joining the community to the new terminal with the permission information share of (total number of terminals −1) × (total number of terminals −1) combined with (total number of terminals−1) of the receiving terminal Provided as a ticket for joining, and when the new terminal establishes the connection with each of the member terminals, attaches all the permission information shares acquired from the corresponding terminal to a message for requesting establishment of the connection The communication system according to claim 1, wherein the communication system is a third stage. The first stage includes
In the case where each member terminal distributes the permission information share,
When the total number of terminals is two, the member terminal distributes one of the three permission information shares generated by the own terminal to the receiving terminal, and one of them is a vote for the own terminal, and the rest Manage the permission information share of one without leaking it to other terminals,
When the total number of terminals is three or more, each of the member terminals is distributed to other terminals out of (the total number of terminals-1) of the permitted information shares generated by the own terminal. 5. The communication system according to claim 4, wherein the remaining one of the permission information share and the permission information is managed without leaking to any other terminal. In the case where the member terminal submits the permission information share to the reception terminal, or in the case where the reception terminal provides the permission information share acquired from each of the member terminals to the new terminal,
6. The communication system according to claim 5, wherein the communication information is submitted by being encrypted by the public key cryptosystem encryption module using the public key of the new terminal including the destination information of the terminal itself. In the second stage,
When all the member terminals have submitted an approval vote to the receiving terminal, the receiving terminal generates the connection establishment information by the connection establishment information generation module, and the connection establishment information is generated by the VSS distributed coding module. Of the connection information shares of (total number of terminals) obtained by distributed encoding with threshold values ((total number of terminals), (total number of terminals)), (total number of terminals-1) is transmitted to all the member terminals. 7. Each of them is provided one by one, and the remaining one connection establishment information share and the connection establishment information which is the original information are managed by the database without leakage to the outside. A communication system according to any one of the above. When the member terminal receives a message indicating the connection establishment request with the permission information share attached from the new terminal, the member terminal participates from all terminals belonging to the community other than the new terminal. In order to confirm whether or not the approval for the subscription is received, the permission information comparison module receives a request for comparison of the permission information from the control module;
When the total number of terminals is two, the two permission information shares attached to the connection establishment request message and one permission information share managed in the database of the own terminal are used. The permission information is restored by a VSS decryption module and compared with the permission information stored in the database of the terminal itself. If there is no difference, the time information included in the permission information is compared. Check whether the difference from the time information is greater than or equal to a predetermined value set in advance. If the difference is less than or equal to the predetermined value, further check whether the destination information is different from the new terminal. Otherwise, return a normal response to the control module,
When the total number of terminals is three or more, the own terminal has distributed among the permission information shares of (total number of terminals−1) × (total number of terminals−1) attached to the connection establishment request message. The VSS decryption module restores the permission information using the permission information share of (total number of terminals −1) and one permission information share managed in the database of the own terminal. A comparison is made as to whether there is a difference from the permission information stored in the database of the terminal. If there is no difference, the difference between the time information included in the permission information and the time information at the time of comparison is the predetermined information. If it is less than the predetermined value, it is further checked whether the destination information is different from the new terminal. If there is no difference, the remaining (the total number of terminals−2) × (Total number of terminals-1) pieces of the permission Whether or not the information share is illegal is confirmed using the permission information share verification information acquired at the time of distribution of the permission information share from the share verification module and the other member terminals. The communication system according to claim 4, wherein a normal response is returned to the control module.   9. The communication system according to claim 8, further comprising permission information validity period setting means for arbitrarily setting the predetermined value indicating the validity period of the permission information. When the new terminal sends a message indicating the connection establishment request to each of the member terminals, and when the connection is normally established,
Each of the member terminals provides the connection establishment information share stored in the database by the own terminal, and the new terminal acquires (total number of terminals −1) of the connection establishments acquired from all of the member terminals. The connection establishment information comparison module provides the reception terminal including information sharing, and the connection terminal confirms whether or not the new terminal has established the connection with all the member terminals. The request for comparison of the connection establishment information is received from the control module, and the connection establishment information share (total number of terminals −1) acquired from the new terminal and the one managed by the database of the own terminal Connection establishment information restored using the connection establishment information share and the VSS decryption module; Compare with the connection establishment information managed in the database of its own terminal to check whether there is a difference. If there is no difference, the time information included in the connection establishment information and the time of comparison 10. The communication system according to claim 8, wherein whether or not the difference from the information is equal to or greater than the predetermined value is checked, and if it is equal to or smaller than the predetermined value, a normal response is returned to the control module.   The communication system according to claim 10, further comprising connection establishment information validity period setting means for arbitrarily setting the predetermined value indicating the validity period of the connection establishment information. When the receiving terminal asks each member terminal to approve or reject the participation / subscription of the new terminal to the community, the new terminal that desires the invitation or participation / subscription is used as the member information as the member information. Let your device know,
If the total number of terminals is three or more, the destination information share obtained by distributedly encoding the destination information of the new terminal by the VSS distributed encoding module and the destination information share verification information are notified, The member terminals exchange the destination information share acquired from the receiving terminal with each other in order to obtain the original destination information. The destination information share verification information acquired from the receiving terminal and the share verification module The communication system according to any one of claims 4 to 11, wherein the original destination information is restored by the VSS decoding module after verifying fraud of all the destination information shares.   When the member terminal submits the permission information share as an approval vote, the share verification module checks whether each permission information share is illegal by the permission information share verification information. The communication system according to any one of claims 4 to 12. In the first stage,
Whether the receiving terminal can proceed to the second stage for the voting in response to a request for approval / disapproval for participation / subscription to the community of the new terminal notified from all the member terminals The communication system according to any one of claims 4 to 13, wherein the result of counting is notified, and the voting result is notified in the second stage. Communicates with a plurality of terminals or public key servers connected to the network, forms a community by establishing connections with the plurality of terminals, and public keys with respect to the public key server A communication method for acquiring a public key in response to an acquisition request,
Forming the community by a full mesh network formed by a full mesh connection between two or more of the terminals;
A request is made to invite a new terminal that does not belong to the community to the community, or a new terminal that does not belong to the community is requested to belong to the community. Configuring with any of the terminals to which it belongs;
Configuring a member terminal with a terminal belonging to the community other than the reception terminal;
When a new terminal joins / subscribes to the community by the permission information generation module, this information is the basis for creating voting information for determining whether to participate / subscribe, and the new terminal is the member terminal Permission information which is information for confirming whether or not the new terminal has obtained approval for the participation / subscription from the member terminal and the reception terminal of the community. Generating step;
Generating connection establishment information necessary for the reception terminal to confirm whether a new terminal has established the connection with the member terminal by a connection establishment information generation module;
The permission information generated independently by the member terminals by the VSS distributed coding module is distributedly coded by the verifiable secret sharing (k, n) threshold method (k ≦ n), and the n permission as voting information is obtained. An information share and one piece of permission information share verification information are generated, and connection establishment information is similarly distributedly encoded by the secret sharing method (k, n) threshold method (k ≦ n) to share n connection establishment information Similarly, when the total number of terminals participating / subscribing to the community is 3 or more, the destination information of the new terminal is distributed by the (k, n) threshold method (k ≦ n) of the verifiable secret sharing Encoding and generating n destination information shares and one destination information share verification information;
The VSS decryption module uses the secret sharing method or the verifiable secret sharing (k, n) threshold method to obtain original information by using k or more shares from n distributed coded shares. Steps to restore,
By using the permission information share verification information and the destination information share verification information by the share verification module, it is confirmed by VSS whether the permission information share, the connection establishment information share, and the destination information share are not illegal. Steps,
Generating a session key by a common key encryption method by the common key generation module;
Have
The permission information generated by the permission information generation module using the database, the permission information share generated using the VSS distributed encoding module and the permission information, the permission information share verification information, and the connection Connection establishment information generated by an establishment information generation module, the connection establishment information share generated using the VSS distributed encoding module and the connection establishment information, a session key generated by the common key generation module, The public key of the terminal other than the own terminal acquired by inquiring the public key server, the private key and public key of the own terminal, the destination information of the other terminal, the VSS distributed encoding module, and the destination information The destination information share to be generated by using the destination information share verification information; And a step to manage, and the terminal a complete list of all of the terminals participating, join the serial community,
When the new terminal requests establishment of the connection to each of the member terminals by the permission information comparison module, whether or not the new terminal has obtained the approval from other terminals belonging to the community in the member terminal. , The permission information share acquired from the new terminal, the permission information share managed by the database of the own terminal, and the permission information restored using the VSS decoding module, and the database of the own terminal Comparing and confirming permission information to be managed;
When the connection terminal receives access from the new terminal by the connection establishment information comparison module, the connection establishment information share acquired from the new terminal indicates whether the connection has been established with all the member terminals and Comparing the connection establishment information share managed by the database of the own terminal and the connection establishment information restored using the VSS decoding module with the connection establishment information managed by the database of the own terminal Step to confirm and
Encrypting information requested by the public key encryption method encryption module using a public key encryption method; and
Encrypting information requested to be encrypted by the common key encryption method using a common key encryption method; and
generating a digest of arbitrary information using a message digest function that is a kind of hash function in which conversion results of a plurality of pieces of information are difficult to be the same by a digest generation module;
Decrypting the information requested for decryption by the public key cryptosystem decryption module using the public key cryptosystem;
Decrypting the information requested for decryption by the common key encryption method decryption module using the common key encryption method;
Determination of whether or not to establish the connection by the intention input module, primary determination of approval / disapproval for participation / subscription of the new terminal to the community, and final determination of approval / disapproval for participation / subscription of the new terminal to the community Determining whether to join or join the community; and
When the message generation module generates a message having the requested content and attaches the information passed when the message generation request is made to the message, the electronic signature and encryption are applied to the message. Executing the attachment with the key encryption system encryption module, the common key encryption system module, and the digest generation module, while executing the attachment with the common key encryption system module when performing only the encryption. When,
The control module requests the permission information generation module to generate the permission information, requests the connection establishment information generation module to generate the connection establishment information, and transmits the permission information share, the permission information share verification information, Or requesting the VSS distributed encoding module to generate the connection establishment information share, the destination information share, and the destination information share verification information, and encrypting the permission information share with a public key. To the public key cryptosystem encryption module, request the public key cryptosystem decryption module to decrypt the encrypted permission information share, and request the intention input module to make the decision. The VSS decryption module to restore the destination information from the destination information share Requesting the permission information comparison module to compare the permission information, requesting the connection establishment information comparison module to compare the connection establishment information, and requesting the common key generation module to generate the session key, Requesting the share verification module to perform fraud check of permission information share or destination information share, inquiring and storing various information in the database, and requesting the message generation module to generate the message;
The message fraud determination module determines whether or not fraudulent activity has been performed during transmission / reception of the received message for all terminals from the digest included in the message and the content of the message. Comparing the digests generated by the generation module for differences;
When all messages are received by the message analysis module and the received message is digitally signed and encrypted, the public key encryption method decryption module, the common key encryption method decryption module, And when the database does not have the public key of the transmission source terminal necessary for decrypting the message, the public key is obtained from the public key server through the control module. In order to check whether the message has been fraudulently requested after the decryption process, the digest generation module generates a digest from the obtained message content and digest, and the message content. The two digests may be The message content to the control module if there is no fraud, and if the message is only encrypted, the common key encryption method Decrypting the message by a decryption module and passing the content of the decrypted message to the control module;
The message processing module transmits the message generated by the message generation module to an external terminal or the public key server, and passes the message received from the external terminal or public key server to the message analysis module. When,
A communication method characterized by comprising: The permission information generation module includes:
16. The communication method according to claim 15, wherein the permission information is configured and generated by time information at the time of generation, the destination information of the new terminal, and an arbitrary random keyword. The connection establishment information generation module
The connection establishment information is configured and generated from time information at the time of generation, the destination information of the new terminal, and an arbitrary random keyword. Communication method. When the total number of terminals is 2,
The reception terminal asks the member terminal whether or not the new terminal participates in or joins the community, and the member terminal uses the VSS distributed coding module based on the permission information generated independently in the case of approval. A first stage of generating three permission information shares, which are voting information, with a threshold (3, 3), and distributing one of them to the receiving terminal;
When the member terminal approves in the first stage, the member terminal submits one permission information share of its own terminal to the receiving terminal as an approval vote, and joins the new terminal to the community. A second stage of deciding whether to join,
In the second stage, when the member terminal is in favor, the permission is obtained by combining the one collected by the receiving terminal as a vote of approval from the member terminal and the one held by the receiving terminal. Providing an information share as a ticket for joining / subscribing to the community to the new terminal, and when the new terminal establishes the connection with the member terminal, all the permitted information shares acquired from the corresponding terminal A third step of attaching to a message for requesting establishment of the connection,
Alternatively, if the total number of terminals is 3 or more,
The receiving terminal asks all the member terminals whether or not the new terminal participates in or joins the community, and each of the member terminals uses the VSS distributed coding module based on the permission information generated independently. ((Total number of terminals), (total number of terminals)) (total number of terminals) pieces of the permission information share and one piece of permission information share verification information are generated, and (total number of terminals) pieces First, after the distribution of the permission information share verification information is distributed to all the other member terminals and the receiving terminal one by one (total number of terminals −1) of the permission information shares. Stage and
When all the member terminals agree in the first step, each of the member terminals agrees with the permission information share of (total number of terminals−2) obtained from all the other member terminals. As a second step to determine whether to join the new terminal to the community by submitting to the receiving terminal as
When all the member terminals are in favor in the second stage, the receiving terminal collects as a vote of favor from all the member terminals (total number of terminals−2) × (total number of terminals−1) Joining the community to the new terminal with the permission information share of (total number of terminals −1) × (total number of terminals −1) combined with (total number of terminals−1) of the receiving terminal Provided as a ticket for joining, and when the new terminal establishes the connection with each of the member terminals, attaches all the permission information shares acquired from the corresponding terminal to a message for requesting establishment of the connection The communication method according to any one of claims 15 to 17, wherein a third stage is performed. The first stage includes
In the case where each member terminal distributes the permission information share,
When the total number of terminals is two, the member terminal distributes one of the three permission information shares generated by the own terminal to the receiving terminal, and one of them is a vote for the own terminal, and the rest Manage the permission information share of one without leaking it to other terminals,
When the total number of terminals is three or more, each of the member terminals is distributed to other terminals out of (the total number of terminals-1) of the permitted information shares generated by the own terminal. 19. The communication method according to claim 18, wherein the remaining one of the permission information share and the permission information is managed without leaking to any other terminal. In the case where the member terminal submits the permission information share to the reception terminal, or in the case where the reception terminal provides the permission information share acquired from each of the member terminals to the new terminal,
The communication method according to claim 19, wherein the communication is performed by using the public key of the new terminal including the destination information of the own terminal to be encrypted and submitted by the public key cryptosystem encryption module. In the second stage,
When all the member terminals have submitted an approval vote to the receiving terminal, the receiving terminal generates the connection establishment information by the connection establishment information generation module, and the connection establishment information is generated by the VSS distributed coding module. Of the connection information shares of (total number of terminals) obtained by distributed encoding with threshold values ((total number of terminals), (total number of terminals)), (total number of terminals-1) is transmitted to all the member terminals. 21. Each one of them is provided one by one, and the remaining one connection establishment information share and the connection establishment information which is the original information are managed by the database without leaking outside. The communication method according to any one of the above. When the member terminal receives a message indicating the connection establishment request with the permission information share attached from the new terminal, the member terminal participates from all terminals belonging to the community other than the new terminal. In order to confirm whether or not the approval for the subscription is received, the permission information comparison module receives a request for comparison of the permission information from the control module;
When the total number of terminals is two, the two permission information shares attached to the connection establishment request message and one permission information share managed in the database of the own terminal are used. The permission information is restored by a VSS decryption module and compared with the permission information stored in the database of the terminal itself. If there is no difference, the time information included in the permission information is compared. Check whether the difference from the time information is greater than or equal to a predetermined value set in advance. If the difference is less than or equal to the predetermined value, further check whether the destination information is different from the new terminal. Otherwise, return a normal response to the control module,
When the total number of terminals is three or more, the own terminal has distributed among the permission information shares of (total number of terminals−1) × (total number of terminals−1) attached to the connection establishment request message. The VSS decryption module restores the permission information using the permission information share of (total number of terminals −1) and one permission information share managed in the database of the own terminal. A comparison is made as to whether there is a difference from the permission information stored in the database of the terminal. If there is no difference, the difference between the time information included in the permission information and the time information at the time of comparison is the predetermined information. If it is less than the predetermined value, it is further checked whether the destination information is different from the new terminal. If there is no difference, the remaining (the total number of terminals−2) × (Total number of terminals-1) pieces of the permission Whether or not the information share is illegal is confirmed using the permission information share verification information acquired at the time of distribution of the permission information share from the share verification module and the other member terminals. The communication method according to any one of claims 18 to 21, wherein a normal response is returned to the control module.   23. The communication method according to claim 22, further comprising permission information validity period setting means for arbitrarily setting the predetermined value indicating the validity period of the permission information. When the new terminal sends a message indicating the connection establishment request to each of the member terminals, and when the connection is normally established,
Each of the member terminals provides the connection establishment information share stored in the database by the own terminal, and the new terminal acquires (total number of terminals −1) of the connection establishments acquired from all of the member terminals. The connection establishment information comparison module provides the reception terminal including information sharing, and the connection terminal confirms whether or not the new terminal has established the connection with all the member terminals. The request for comparison of the connection establishment information is received from the control module, and the connection establishment information share (total number of terminals −1) acquired from the new terminal and the one managed by the database of the own terminal Connection establishment information restored using the connection establishment information share and the VSS decryption module; Compare with the connection establishment information managed in the database of its own terminal to check whether there is a difference. If there is no difference, the time information included in the connection establishment information and the time of comparison 24. The communication method according to claim 22, wherein whether or not a difference from information is equal to or greater than the predetermined value is checked, and if the difference is equal to or smaller than the predetermined value, a normal response is returned to the control module.   The communication method according to claim 24, further comprising connection establishment information validity period setting means for arbitrarily setting the predetermined value indicating the validity period of the connection establishment information. When the receiving terminal asks each member terminal to approve or reject the participation / subscription of the new terminal to the community, the new terminal that desires the invitation or participation / subscription is used as the member information as the member information. Let your device know,
If the total number of terminals is three or more, the destination information share obtained by distributedly encoding the destination information of the new terminal by the VSS distributed encoding module and the destination information share verification information are notified, The member terminals exchange the destination information share acquired from the receiving terminal with each other in order to obtain the original destination information. The destination information share verification information acquired from the receiving terminal and the share verification module 26. The communication method according to claim 18, wherein the original destination information is restored by the VSS decryption module after verifying fraud of all the destination information shares.   When the member terminal submits the permission information share as an approval vote, the share verification module checks whether each permission information share is illegal by the permission information share verification information. The communication method according to any one of claims 18 to 26. In the first stage,
Whether the receiving terminal can proceed to the second stage for the voting in response to a request for approval / disapproval for participation / subscription to the community of the new terminal notified from all the member terminals 28. The communication method according to claim 18, wherein the result of counting is notified, and the voting result is notified in the second stage. Communicates with a plurality of terminals or public key servers connected to the network, forms a community by establishing connections with the plurality of terminals, and public keys with respect to the public key server A communication program for acquiring a public key in response to an acquisition request,
Forming the community by a full mesh network formed by a full mesh connection between two or more of the terminals;
A request is made to invite a new terminal that does not belong to the community to the community, or a new terminal that does not belong to the community is requested to belong to the community. Configuring with any of the terminals to which it belongs;
Configuring a member terminal with a terminal belonging to the community other than the reception terminal;
When a new terminal joins / subscribes to the community by the permission information generation module, this information is the basis for creating voting information for determining whether to participate / subscribe, and the new terminal is the member terminal Permission information which is information for confirming whether or not the new terminal has obtained approval for the participation / subscription from the member terminal and the reception terminal of the community. Generating step;
Generating connection establishment information necessary for the reception terminal to confirm whether a new terminal has established the connection with the member terminal by a connection establishment information generation module;
The permission information generated independently by the member terminals by the VSS distributed coding module is distributedly coded by the verifiable secret sharing (k, n) threshold method (k ≦ n), and the n permission as voting information is obtained. An information share and one piece of permission information share verification information are generated, and connection establishment information is similarly distributedly encoded by the secret sharing method (k, n) threshold method (k ≦ n) to share n connection establishment information Similarly, when the total number of terminals participating / subscribing to the community is 3 or more, the destination information of the new terminal is distributed by the (k, n) threshold method (k ≦ n) of the verifiable secret sharing Encoding and generating n destination information shares and one destination information share verification information;
The VSS decryption module uses the secret sharing method or the verifiable secret sharing (k, n) threshold method to obtain original information by using k or more shares from n distributed coded shares. Steps to restore,
By using the permission information share verification information and the destination information share verification information by the share verification module, it is confirmed by VSS whether the permission information share, the connection establishment information share, and the destination information share are not illegal. Steps,
Generating a session key by a common key encryption method by the common key generation module;
Have
The permission information generated by the permission information generation module using the database, the permission information share generated using the VSS distributed encoding module and the permission information, the permission information share verification information, and the connection Connection establishment information generated by an establishment information generation module, the connection establishment information share generated using the VSS distributed encoding module and the connection establishment information, a session key generated by the common key generation module, The public key of the terminal other than the own terminal acquired by inquiring the public key server, the private key and public key of the own terminal, the destination information of the other terminal, the VSS distributed encoding module, and the destination information The destination information share to be generated by using the destination information share verification information; And a step to manage, and the terminal a complete list of all of the terminals participating, join the serial community,
When the new terminal requests establishment of the connection to each of the member terminals by the permission information comparison module, whether or not the new terminal has obtained the approval from other terminals belonging to the community in the member terminal. , The permission information share acquired from the new terminal, the permission information share managed by the database of the own terminal, and the permission information restored using the VSS decoding module, and the database of the own terminal Comparing and confirming permission information to be managed;
When the connection terminal receives access from the new terminal by the connection establishment information comparison module, the connection establishment information share acquired from the new terminal indicates whether the connection has been established with all the member terminals and Comparing the connection establishment information share managed by the database of the own terminal and the connection establishment information restored using the VSS decoding module with the connection establishment information managed by the database of the own terminal Step to confirm and
Encrypting information requested by the public key encryption method encryption module using a public key encryption method; and
Encrypting information requested to be encrypted by the common key encryption method using a common key encryption method; and
generating a digest of arbitrary information using a message digest function that is a kind of hash function in which conversion results of a plurality of pieces of information are difficult to be the same by a digest generation module;
Decrypting the information requested for decryption by the public key cryptosystem decryption module using the public key cryptosystem;
Decrypting the information requested for decryption by the common key encryption method decryption module using the common key encryption method;
Determination of whether or not to establish the connection by the intention input module, primary determination of approval / disapproval for participation / subscription of the new terminal to the community, and final determination of approval / disapproval for participation / subscription of the new terminal to the community Determining whether to join or join the community; and
When the message generation module generates a message having the requested content and attaches the information passed when the message generation request is made to the message, the electronic signature and encryption are applied to the message. Executing the attachment with the key encryption system encryption module, the common key encryption system module, and the digest generation module, while executing the attachment with the common key encryption system module when performing only the encryption. When,
The control module requests the permission information generation module to generate the permission information, requests the connection establishment information generation module to generate the connection establishment information, and transmits the permission information share, the permission information share verification information, Or requesting the VSS distributed encoding module to generate the connection establishment information share, the destination information share, and the destination information share verification information, and encrypting the permission information share with a public key. To the public key cryptosystem encryption module, request the public key cryptosystem decryption module to decrypt the encrypted permission information share, and request the intention input module to make the decision. The VSS decryption module to restore the destination information from the destination information share Requesting the permission information comparison module to compare the permission information, requesting the connection establishment information comparison module to compare the connection establishment information, and requesting the common key generation module to generate the session key, Requesting the share verification module to perform fraud check of permission information share or destination information share, inquiring and storing various information in the database, and requesting the message generation module to generate the message;
The message fraud determination module determines whether or not fraudulent activity has been performed during transmission / reception of the received message for all terminals from the digest included in the message and the content of the message. Comparing the digests generated by the generation module for differences;
When all messages are received by the message analysis module and the received message is digitally signed and encrypted, the public key encryption method decryption module, the common key encryption method decryption module, And when the database does not have the public key of the source terminal necessary for decrypting the message, the public key server obtains the public key through the control module. In order to check whether the message has been fraudulently requested after the decryption process, the digest generation module generates a digest from the obtained message content and digest, and the message content. The two digests may be The message content to the control module if there is no fraud, and if the message is only encrypted, the common key encryption method Decrypting the message by a decryption module and passing the content of the decrypted message to the control module;
The message processing module transmits the message generated by the message generation module to an external terminal or the public key server, and passes the message received from the external terminal or public key server to the message analysis module. When,
A communication program characterized by comprising: The permission information generation module includes:
30. The communication program according to claim 29, wherein the permission information is configured and generated by time information at the time of generation, the destination information of the new terminal, and an arbitrary random keyword. The connection establishment information generation module
The said connection establishment information is comprised and produced | generated by the time information at the time of production | generation, the said destination information of the said new terminal, and arbitrary random keywords, It produces | generates in any one of Claim 29 or 30 characterized by the above-mentioned. Communication program. When the total number of terminals is 2,
The reception terminal asks the member terminal whether or not the new terminal participates in or joins the community, and the member terminal uses the VSS distributed coding module based on the permission information generated independently in the case of approval. A first stage of generating three permission information shares, which are voting information, with a threshold (3, 3), and distributing one of them to the receiving terminal;
When the member terminal approves in the first stage, the member terminal submits one permission information share of its own terminal to the receiving terminal as an approval vote, and joins the new terminal to the community. A second stage of deciding whether to join,
In the second stage, when the member terminal is in favor, the permission is obtained by combining the one collected by the receiving terminal as a vote of approval from the member terminal and the one held by the receiving terminal. Providing an information share as a ticket for joining / subscribing to the community to the new terminal, and when the new terminal establishes the connection with the member terminal, all the permitted information shares acquired from the corresponding terminal A third step of attaching to a message for requesting establishment of the connection,
Alternatively, if the total number of terminals is 3 or more,
The receiving terminal asks all the member terminals whether or not the new terminal participates in or joins the community, and each of the member terminals uses the VSS distributed coding module based on the permission information generated independently. ((Total number of terminals), (total number of terminals)) (total number of terminals) pieces of the permission information share and one piece of permission information share verification information are generated, and (total number of terminals) pieces First, after the distribution of the permission information share verification information is distributed to all the other member terminals and the receiving terminal one by one (total number of terminals −1) of the permission information shares. Stage and
When all the member terminals agree in the first step, each of the member terminals agrees with the permission information share of (total number of terminals−2) obtained from all the other member terminals. As a second step to determine whether to join the new terminal to the community by submitting to the receiving terminal as
When all the member terminals are in favor in the second stage, the receiving terminal collects as a vote of favor from all the member terminals (total number of terminals−2) × (total number of terminals−1) Joining the community to the new terminal with the permission information share of (total number of terminals −1) × (total number of terminals −1) combined with (total number of terminals−1) of the receiving terminal Provided as a ticket for joining, and when the new terminal establishes the connection with each of the member terminals, attaches all the permission information shares acquired from the corresponding terminal to a message for requesting establishment of the connection 32. The communication program according to claim 29, wherein the communication program is a third stage. The first stage includes
In the case where each member terminal distributes the permission information share,
When the total number of terminals is two, the member terminal distributes one of the three permission information shares generated by the own terminal to the receiving terminal, and one of them is a vote for the own terminal, and the rest Manage the permission information share of one without leaking it to other terminals,
When the total number of terminals is three or more, each of the member terminals is distributed to other terminals out of (the total number of terminals-1) of the permitted information shares generated by the own terminal. The communication program according to claim 32, wherein the remaining one of the permission information share and the permission information is managed without leaking to any other terminal. In the case where the member terminal submits the permission information share to the reception terminal, or in the case where the reception terminal provides the permission information share acquired from each of the member terminals to the new terminal,
34. The communication program according to claim 33, wherein the communication program is encrypted and submitted by the public key cryptosystem encryption module using the public key of the new terminal including the destination information of the terminal itself. In the second stage,
When all the member terminals have submitted an approval vote to the receiving terminal, the receiving terminal generates the connection establishment information by the connection establishment information generation module, and the connection establishment information is generated by the VSS distributed coding module. Of the connection information shares of (total number of terminals) obtained by distributed encoding with threshold values ((total number of terminals), (total number of terminals)), (total number of terminals-1) is transmitted to all the member terminals. 35. The present invention provides each one by one, and manages the remaining one connection establishment information share and the connection establishment information that is the original information by the database without leaking outside. A communication program according to any of the above. When the new terminal transmits a message indicating the connection establishment request to each of the member terminals, and when the connection is normally established, the member terminals are all terminals to which the new terminal belongs to the community other than its own terminal. The permission information comparison module receives a request for comparison of the permission information from the control module in order to confirm whether or not it is approved for participation / subscription from
When the total number of terminals is two, the two permission information shares attached to the connection establishment request message and one permission information share managed in the database of the own terminal are used. The permission information is restored by a VSS decryption module and compared with the permission information stored in the database of the terminal itself. If there is no difference, the time information included in the permission information is compared. Check whether the difference from the time information is greater than or equal to a predetermined value set in advance. If the difference is less than or equal to the predetermined value, further check whether the destination information is different from the new terminal. Otherwise, return a normal response to the control module,
When the total number of terminals is three or more, the own terminal has distributed among the permission information shares of (total number of terminals−1) × (total number of terminals−1) attached to the connection establishment request message. The VSS decryption module restores the permission information using the permission information share of (total number of terminals −1) and one permission information share managed in the database of the own terminal. A comparison is made as to whether there is a difference from the permission information stored in the database of the terminal. If there is no difference, the difference between the time information included in the permission information and the time information at the time of comparison is the predetermined information. If it is less than the predetermined value, it is further checked whether the destination information is different from the new terminal. If there is no difference, the remaining (the total number of terminals−2) × (Total number of terminals-1) pieces of the permission Whether or not the information share is illegal is confirmed using the permission information share verification information acquired at the time of distribution of the permission information share from the share verification module and the other member terminals. 36. The communication program according to claim 32, wherein a normal response is returned to the control module.   The communication program according to claim 36, further comprising permission information validity period setting means for arbitrarily setting the predetermined value indicating the validity period of the permission information. When the new terminal sends a message indicating the connection establishment request to all the member terminals, and when the connection is successfully established,
Each of the member terminals provides the connection establishment information share stored in the database by the own terminal, and the new terminal acquires (total number of terminals −1) of the connection establishments acquired from all of the member terminals. The connection establishment information comparison module provides the reception terminal including information sharing, and the connection terminal confirms whether or not the new terminal has established the connection with all the member terminals. The request for comparison of the connection establishment information is received from the control module, and the connection establishment information share (total number of terminals −1) acquired from the new terminal and the one managed by the database of the own terminal Connection establishment information restored using the connection establishment information share and the VSS decryption module; Compare with the connection establishment information managed in the database of its own terminal to check whether there is a difference. If there is no difference, the time information included in the connection establishment information and the time of comparison 38. The communication program according to claim 36, wherein a check is made as to whether or not a difference from the information is greater than or equal to the predetermined value, and if the difference is not greater than the predetermined value, a normal response is returned to the control module.   The communication program according to claim 38, further comprising connection establishment information validity period setting means for arbitrarily setting the predetermined value indicating the validity period of the connection establishment information. When the receiving terminal asks each member terminal to approve or reject the participation / subscription of the new terminal to the community, the new terminal that desires the invitation or participation / subscription is used as the member information as the member information. Let your device know,
If the total number of terminals is three or more, the destination information share obtained by distributedly encoding the destination information of the new terminal by the VSS distributed encoding module and the destination information share verification information are notified, The member terminals exchange the destination information share acquired from the receiving terminal with each other in order to obtain the original destination information. The destination information share verification information acquired from the receiving terminal and the share verification module 40. The communication program according to claim 32, wherein the original destination information is restored by the VSS decryption module after verifying fraud of all the destination information shares.   When the member terminal submits the permission information share as an approval vote, the share verification module checks whether each permission information share is illegal by the permission information share verification information. The communication program according to any one of claims 32 to 40. In the first stage,
Whether the receiving terminal can proceed to the second stage for the voting in response to a request for approval / disapproval for participation / subscription to the community of the new terminal notified from all the member terminals 42. The communication program according to any one of claims 32 to 41, wherein the communication result is notified, and the voting result is notified in the second stage.

Images