JP4401415B2 - Electronic bulletin board providing device, message posting method, posted message search method, and electronic bulletin board providing program - Google Patents

Description

The present invention is child BBS providing apparatus electrostatic defended the anonymity of the sender and recipient of the data, message posting process, post message retrieval method, and an electronic relates bulletin board providing program, in particular child BBS providing apparatus electrodeposition using onion routing techniques, The present invention relates to a message posting method, a posted message search method, and an electronic bulletin board providing program .

  Various information exchanges are actively performed through the Internet. In a technique generally used on the Internet, if a transmitted packet is analyzed, a receiver can be determined from the header of the packet and a packet route can be traced. As a result, there is a risk that the privacy of individual users of the Internet is infringed. For example, if the location (IP address or the like) of the terminal used by the poster is known from the content posted on the anonymous bulletin board, there is a risk of harassment by a malicious third party.

  Therefore, various techniques for protecting the anonymity of data senders and receivers on the Internet have been considered. In order to protect the anonymity of data transmission / reception, it is necessary to encrypt all data communication and not to leak the packet transmission path.

  In order to prevent the leakage of the packet transmission path, it is necessary to shut out the leakage of information such as the reception source and transfer destination of the packet during communication by utilizing a plurality of relay points (routers). As such a transmission path leakage prevention technique, a technique named “onion routing” is known (see, for example, Patent Document 1).

  In the method of onion routing, routing is performed by a robust and fixed router called an onion router. In the transmission terminal, a transmission path to the transmission partner is determined in advance, and information on the transmission path of the packet is encrypted using the public key of each onion router that relays the packet.

  The onion router that receives the packet decrypts the information on the transmission path with its own secret key. This decryption determines the next transfer destination of the packet, and the onion router transfers the packet to the next node (onion router or receiving terminal). In this manner, each onion router can maintain a concealed state except for the next transfer destination, and therefore cannot identify the final receiving terminal information. Further, when sending a packet in the onion router, it is possible to prevent the transmission source from leaking by not adding to the packet information related to the transmission path up to that point.

As described above, in onion routing, the route information to the destination in the data packet is multiplexed and stored, so that part of the route information is provided to each node that performs routing and those who perform skimming on the network. I can only refer to it.
US Pat. No. 6,266,704

  However, the conventional onion routing method is difficult to apply to an environment in which the node configuration changes dynamically. As an environment in which the node configuration dynamically changes, there is a P2P (Peer to Peer) network in particular.

In a P2P network, participation of a Peer node in the network or leaving the network is optional. For this reason, when communication is performed on the P2P network, the packet is transferred to the peer node of the transmission partner while performing P2P communication between the peer nodes participating at that time. When applying the technique of such onion routing for P2P environment, the following problems that Ji live.
・ Fixed routers and fixed routes cannot be determined in advance.
-It is difficult to dynamically cope with node configuration changes during routing.

  For this reason, in order to perform anonymous communication in an unstable network such as a P2P network, route discovery must be performed dynamically and anonymously to cope with node configuration changes during routing.

The present invention has been made in view of such a point, and an electronic bulletin board providing device , a message posting method, a posted message search method, and the like, in which messages can be exchanged anonymously between a contributor and a viewer of the post, and The purpose is to provide an electronic bulletin board providing program .

To solve the above SL problems, the electronic bulletin board provided apparatus for performing message exchange anonymously over the network, the message to be posted on the bulletin board, the first return of a first transmission route which has followed from author source Registration means for registering the content of the data packet in a database upon receiving a posted data packet addressed to itself including anonymous route information and a first adjacent node identifier that is identification information of an adjacent node on the first transmission route; A search condition for the message, second return anonymous route information indicating a second transmission route traced from a sender of the searcher, a second adjacent node identifier which is identification information of an adjacent node on the second transmission route, And receiving a search data packet addressed to itself including the transmission source public key for reply data encryption, Search means for searching the database, encryption means for encrypting the message detected by the search means, the first return anonymous route information, and the first adjacent node identifier with the source public key; Packet generating means for generating encrypted data and a response data packet including the second return anonymous route information; and transmitting means for transmitting the response data packet to the node indicated by the second adjacent node identifier; , An electronic bulletin board providing device is provided.

  As a result, the poster's message is notified to the searcher of another country name while the poster on the electronic bulletin board remains anonymous.

In the present invention, when a search for a message posted to an electronic bulletin board via an anonymous route is performed, the anonymous route information to the sender of the poster is added to the message and sent to the searcher. A searcher can respond to an anonymous poster via an anonymous route.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the outline of the invention applied to the embodiment will be described, and then the specific contents of the embodiment will be described.

[Summary of Invention]
FIG. 1 is a conceptual diagram of the invention applied to the embodiment. Communication according to the present invention is performed between the transmission node 1, the relay node 2, and the reception node 3. As will be described later, there are generally a plurality of relay nodes 2.

  Upon receiving the route search request specifying the destination by the destination identifier, the sending node 1 encrypts the own node identifier, which is its own identification information, in a format that only itself can be decrypted to obtain reply anonymous route information (step S1). ). In order to perform encryption only by itself, for example, encryption is performed with a public key (encryption key) corresponding to a secret key (decryption key) possessed only by the transmission node 1.

  Next, the transmission node 1 generates a route search packet including an arbitrarily generated anonymous identifier, destination identifier, reply anonymous route information, and a transmission source public key for reply data encryption (step S2). The anonymous identifier is used for associating the transmitted route search packet with the returned route notification packet. The destination identifier is information for specifying the destination receiving node 3. The destination identifier may be information published in advance. The transmission source public key is an encryption key for encrypting information when another node passes information such as its own node identifier to the transmission node 1. A secret key (decryption key) corresponding to the transmission source public key is stored in advance in the transmission node 1.

Finally, the transmission node 1 transmits a route search packet by broadcast (step S3).
When the relay node 2 receives the route search packet, the relay node 2 encrypts the return anonymous route information and the adjacent node identifier in a format that can only be decrypted by itself (step S4). The adjacent node identifier is an identifier of a node adjacent to the relay node 2 in the route search packet transmission route. If the route search packet is directly sent from the transmission node 1, the node identifier of the transmission node 1 is the adjacent node identifier. In the encryption process, for example, encryption is performed with a public key (encryption key) corresponding to a secret key (decryption key) possessed by the relay node 2. Since the reply anonymous route information has already been encrypted at the transmission node or other relay node interposed during transmission, it is encrypted in multiples by the encryption in step S4. Moreover, by encrypting including the adjacent node identifier, the node identifier of the adjacent node can be recognized when the information is decrypted.

  Next, the relay node 2 adds its own node identifier, which is its own identification information, to the route search packet (step S5). Finally, the relay node 2 transmits a route search packet by broadcast (step S6). When a third party analyzes the transmitted route search packet, it can be recognized that the packet has been transmitted from the relay node 2, but the previous transfer route cannot be known.

  When receiving the route search packet including the destination identifier indicating that the packet is addressed to the receiving node 3, the receiving node 3 discloses the node identifier as its own identification information and the receiving node disclosure for encrypting the information addressed to the receiving node 3. The key is encrypted with the source public key to obtain route information (step S7). The transmission source public key can be acquired from the route search packet. Since the pair of the node identifier and the receiving node public key is encrypted with the transmission source public key, only the transmission node 1 can refer to these pieces of information.

  Next, the receiving node 3 designates the route notification destination by the anonymous identifier of the transmitting node 1, and generates a route notification packet including reply anonymous route information, route information, and a transmission source public key (step S8). Finally, the receiving node 3 transmits a route notification packet to the node indicated by the adjacent node identifier (step S9). As a result, a route notification packet including the node identifier of the receiving node 3 and the public key is returned through a route according to the return anonymous route information.

  When the relay node 2 receives the route notification packet, the relay node 2 encrypts the own node identifier, which is its own identification information, and the relay node public key for encrypting the information addressed to the own node with the transmission source public key, and adds it to the route information. (Step S10). In this way, by adding a pair of the node identifier and public key of each relay node to the route information, the anonymous route can be notified to the transmitting node. When adding a pair of a node identifier and a public key to the route information, it is added according to a predetermined rule so that the order of adding information can be determined. For example, new information is added before the original information in the route information. Thereby, in the transmission node 1, the arrangement | sequence of each node on an anonymous route can be recognized.

  Next, the relay node 2 decodes the reply anonymous route information to obtain the next node identifier (adjacent node identifier in the route search packet) indicating the next transmission destination node, and the decoded data The route notification packet is set as the reply anonymous route information (step S11). Finally, the relay node 2 transmits a route notification packet to the node indicated by the next node identifier (step S12). Thereby, the route notification packet in which the node identifier of the relay node 2 and the public key are added to the route information is transferred to the route according to the return anonymous route information.

  Upon receiving the route notification packet, the sending node 1 decrypts the route information with the source private key corresponding to the source public key (step S13). Then, the transmission node 1 stores the set of the identifier and public key of each node on the route to the destination obtained by the decryption in the recording device while maintaining the arrangement (step S14). By referring to the stored information, the anonymous route to the receiving node 3 can be recognized. In addition, if the public key of each node is used, only the next node on the anonymous route can be notified to each node on the route.

  In this manner, the anonymity of the data sender / receiver can be protected, and the data transmission / reception route can be dynamically searched for highly anonymous data communication. In addition, even if the node configuration is changed at the time of routing, the certainty of data transmission can be improved by transmitting data via another anonymous route detected earlier.

  The function of anonymous communication as described above can be applied to a P2P network. That is, since each node can search for an anonymous route as appropriate, even if the network configuration changes dynamically, data communication can be performed while the source is concealed by the anonymous route.

By the way, the transmission source anonymous identifier and the transmission source public key included in the route search packet can be appropriately changed. For example, each time a route search packet is transmitted, a different anonymous identifier and a different source public key can be used. By not fixing the transmission source public key, the anonymity of the transmission source can be improved. That is, if the anonymous identifier and the public key are always fixed to the sender, the following problem occurs.
1. When a plurality of unencrypted messages (postings on a bulletin board, etc.) having the same anonymous identifier are collected, there is a possibility that the sender can be specified from the contents.
2. Even in an encrypted message, (for example door was, if you read the reply to post an anonymous message board post's) was the person who solved the encryption there is a possibility that you can identify the caller from the contents.

  Therefore, by not fixing the anonymous identifier and public key of the same sender between messages, the node that searches the anonymous bulletin board, the skimming on the network, or the recipient of the reply message specifies the sender of the message. Can be prevented. That is, the unlinkability between messages can be improved by managing the anonymous identifier of the node and the public key. If this is used for an electronic bulletin board, an anonymous bulletin board function that protects the anonymity of the sender and receiver of data can be realized. Note that unlinkability indicates that it cannot be determined that two types of processing have been performed by the same user.

[Embodiment of the Invention]
A specific example for realizing the above functions will be described below as an embodiment of the present invention. In the following embodiments, the present invention is applied to a P2P network, and an anonymous communication function is realized by a P2P onion proxy and a P2P onion router. A route search according to the P2P onion route discovery protocol is performed by the P2P onion proxy of each P2P onion node. Further, P2P onion routing is performed by the P2P onion router of each P2P onion node, and P2P onion route information is detected.

  Here, the P2P onion route discovery protocol is a protocol for discovering the P2P onion route to the receiving side P2P onion node. The P2P onion proxy is a functional unit that governs the P2P onion route discovery protocol of the P2P onion node. The P2P onion route is route information that is encrypted multiple times and can cope with a node configuration change. The P2P onion router is a functional unit that controls P2P onion routing processing according to the P2P onion route information in the P2P onion node.

  FIG. 2 is a conceptual diagram of an anonymous communication network. In the present embodiment, the P2P onion node 100 participates in the anonymous communication network 10 including the P2P onion nodes 200, 300, 410, 420, 430, 440, and 450. Here, the node name of the P2P onion node 100 is “A”, the node name of the P2P onion node 200 is “B”, the node name of the P2P onion node 410 is “C”, and the node name of the P2P onion node 420 is “D”. , The node name of the P2P onion node 430 is “E”, the node name of the P2P onion node 440 is “F”, the node name of the P2P onion node 450 is “G”, and the node name of the P2P onion node 300 is “X”. .

The P2P onion node 100 participates in the anonymous communication network 10 by performing P2P communication connection with the P2P onion node 200.
The P2P onion node 200 has established a P2P communication connection with the other P2P onion nodes 410, 420, 440, and 450. The P2P onion node 410 further establishes a P2P communication connection with the P2P onion node 430. Similarly, the P2P onion node 420 establishes a P2P communication connection with the P2P onion node 430. The P2P onion node 430 further establishes a P2P communication connection with the P2P onion node 300.

As described above, in the P2P network, a communication network is established by a chain of P2P connections between a large number of P2P onion nodes.
FIG. 3 is a diagram illustrating a hardware configuration example of the P2P onion node used in the embodiment of the present invention. The entire P2P onion node 100 is controlled by a CPU (Central Processing Unit) 101. A random access memory (RAM) 102, a hard disk drive (HDD) 103, a graphic processing device 104, an input interface 105, and a communication interface 106 are connected to the CPU 101 via a bus 107.

  The RAM 102 temporarily stores at least part of an OS (Operating System) program and application programs to be executed by the CPU 101. The RAM 102 stores various data necessary for processing by the CPU 101. The HDD 103 stores an OS and application programs.

  A monitor 11 is connected to the graphic processing device 104. The graphic processing device 104 displays an image on the screen of the monitor 11 in accordance with a command from the CPU 101. A keyboard 12 and a mouse 13 are connected to the input interface 105. The input interface 105 transmits a signal transmitted from the keyboard 12 or the mouse 13 to the CPU 101 via the bus 107.

The communication interface 106 transmits / receives data to / from other P2P onion nodes 200.
With the hardware configuration as described above, the processing functions of the present embodiment can be realized. Although FIG. 3 shows an example of the hardware configuration of the P2P onion node 100, other P2P onion nodes 200, 300, 410, 420, 430, 440, and 450 can be realized with the same hardware configuration. .

By the way, each P2P onion node according to the present embodiment is roughly divided into an anonymous communication infrastructure connection authentication function, an anonymous route discovery function, and an anonymous communication function.
The anonymous communication infrastructure connection authentication function is an authentication request function for itself to participate in the anonymous communication network 10 and a function for authenticating the P2P onion node when another P2P onion node participates in the anonymous communication network 10. is there. By performing connection authentication for the P2P onion node participating in the anonymous communication network 10, it is possible to prevent anyone other than those who have been registered as members in advance from participating in the anonymous communication network 10.

The anonymous route discovery function is a function for searching for a transmission path to a transmission partner according to the P2P onion route discovery protocol.
The anonymous communication function is a function for performing anonymous communication through the discovered route.

  FIG. 4 is a block diagram showing a schematic functional configuration of the P2P onion node. The P2P onion node 100 includes a P2P onion proxy 110, a P2P onion router 120, and a plurality of applications 131 and 132. The P2P onion proxy 110 has an anonymous communication infrastructure connection authentication function and an anonymous route discovery function. The P2P onion router 120 has an anonymous communication function. The applications 131 and 132 transmit and receive messages in response to operation inputs from the user. In the example of FIG. 4, the application 131 transmits a message and the application 132 receives a message.

  The P2P onion node 200 has a P2P onion proxy 210 and a P2P onion router 220. The P2P onion proxy 210 has an anonymous communication infrastructure connection authentication function and an anonymous route discovery function. The P2P onion router 220 has an anonymous communication function.

  For example, when a connection request to the anonymous communication network 10 is issued from the applications 131 and 132 between the P2P onion nodes 100 and 200 having such a functional configuration, the P2P onion proxy 110 of the P2P onion node 100 and the P2P onion node 200 Mutual authentication of the connection is performed by the anonymous communication infrastructure connection authentication function with the P2P onion proxy 210 operating in cooperation.

  When the application 131 receives a message transmission request from the user, a search and acquisition request for a P2P onion route is issued to the P2P onion proxy 110. Then, the route search process is performed by the anonymous route discovery function between the P2P onion proxy 110 of the P2P onion node 100 and the P2P onion proxy 210 of the P2P onion node 200 operating in accordance with the P2P onion route discovery protocol. When the route search is completed, a message transmission request is issued from the application 131 to the P2P onion router 120. Then, the anonymous communication function between the P2P onion router 120 of the P2P onion node 100 and the P2P onion router 220 of the P2P onion node 200 operates in cooperation to perform onion routing, and a message is transmitted by a data packet.

  Further, when a message from another P2P onion node to the P2P onion node 100 is sent by onion routing, the message is passed from the P2P onion router 120 to the application 132.

  Next, functions of each P2P onion node for realizing the embodiment of the present invention will be described in detail. Each P2P onion node may be a packet sender (transmission peer), a packet receiver (reception peer), or a packet routing router (relay peer). . Therefore, each P2P onion node needs to have functions as a transmission peer, a reception peer, and a relay peer.

  FIG. 5 is a block diagram showing a functional configuration of the P2P onion node. The P2P onion node 100 includes a P2P onion proxy 110, a P2P onion router 120, an application 131, a membership card information holding unit 141, a fixed key holding unit 142, an anonymous route information holding unit 143, a temporary key generation unit 151, and an anonymous ID generation unit. 152.

The P2P onion proxy 110 includes an anonymous communication connection unit 111, an anonymous route search request unit 112, a route search request relay unit 113, and a route search request response unit 114.
The anonymous communication connection unit 111 executes an anonymous communication board connection authentication process. Specifically, when the anonymous communication connection unit 111 receives a connection request to the anonymous board from the application 131, the anonymous communication connection unit 111 acquires the membership card information from the membership card information holding unit 141, and the fixed public key 142a from the fixed key holding unit 142. To get. Then, the anonymous communication connection unit 111 performs connection authentication with other connectable P2P onion nodes using the membership card information and the fixed public key 142a. The anonymous communication connection unit 111 also performs connection authentication using the membership card information and the fixed public key 142a even when a connection authentication request is received from another P2P onion node.

  The anonymous route search request unit 112 realizes a route search request transmission function in the P2P onion route discovery protocol. Specifically, when the anonymous route search request unit 112 receives the P2P onion route search request from the application 131, the anonymous route search request unit 112 acquires the fixed public key 142 a from the fixed key holding unit 142, and the temporary public key and the temporary key from the temporary key generation unit 151. Receive a private key. Further, the anonymous route search request unit 112 acquires an anonymous ID from the anonymous ID generation unit 152. And the anonymous route search request | requirement part 112 produces | generates the route search packet containing the acquired key information, anonymous ID, own node ID, etc., and transmits with broadband. The node ID is set in the route search packet in a state encrypted with the public key.

  The route search request relay unit 113 implements a route search request relay function in the P2P onion route discovery protocol. Specifically, when a route search packet is received from another P2P onion node, the route search request relay unit 113 acquires the fixed public key 142 a from the fixed key holding unit 142. Next, the route search request relay unit 113 encrypts the information in the return onion (route stack: indicating the transmission path up to that point) in the route search packet with its own fixed public key 142a. After that, the route search request relay unit 113 adds its own node ID to the encrypted information to make a new return onion. Then, the route search request relay unit 113 transfers the route search packet with the updated route stack to other P2P onion nodes (excluding the source of the route search packet).

  The route search request response unit 114 implements a response function to a route search request in the P2P onion route discovery protocol. Specifically, the route search request response unit 114 generates a route notification packet for the P2P onion node when the route search request response unit 114 is designated as a search target node in the route search packet sent from another P2P onion node. . When responding, the route search request response unit 114 acquires the fixed public key 142 a from the fixed key holding unit 142. Then, the route search request response unit 114 uses the temporary public key of the route search packet transmission source to encrypt its node ID and the fixed public key 142a and include them in the route notification packet. The route notification packet is transmitted via the anonymous data transmission unit 121 of the P2P onion router 120.

The P2P onion router 120 includes an anonymous data transmission unit 121, an anonymous data relay unit 122, and an anonymous data reception unit 123.
The anonymous data transmission unit 121 realizes a function of transmitting an anonymous communication data packet in the anonymous communication function. Specifically, the anonymous data transmission unit 121 generates and transmits a data packet for anonymous communication in response to a request from the application 131 or the like. The data packet includes a destination onion indicating an anonymous route. The destination onion is obtained by encrypting information on the next transmission destination of each P2P onion node using the public key of each P2P onion node on the anonymous route.

  The anonymous data relay unit 122 realizes a data packet relay function for anonymous communication in the anonymous communication function. Specifically, the anonymous data relay unit 122 decrypts the destination onion in the data packet with its own secret key, and confirms the next transmission destination. Then, the anonymous data relay unit 122 transfers the data packet to the next transmission destination.

  The anonymous data receiving unit 123 realizes a function of receiving data packets for anonymous communication in the anonymous communication function. Specifically, if the anonymous ID of the transmission destination of the data packet is its own ID, the anonymous data receiving unit 123 recognizes that the data packet is addressed to itself, and notifies the application 131 of the data (in the payload) Data). In addition, when the received packet addressed to itself is a route notification packet, the anonymous data receiving unit 123 recognizes the anonymous route from the content and stores it in the anonymous route information holding unit 143.

The application 131 executes various processes using anonymous communication in accordance with a user operation input or the like.
The membership card information holding unit 141 is information passed to a user who has performed a predetermined procedure for participating in the anonymous communication network 10. Only the P2P onion node having the membership card information can participate in the anonymous communication network 10.

  The fixed key holding unit 142 stores key information prepared in advance. The key information is a fixed public key 142a and a fixed secret key 142b. The encrypted data encrypted with the fixed public key 142a can be decrypted only with the fixed secret key 142b. Note that the fixed public key 142a and the fixed secret key 142b can be supplied as part of the membership card information.

The anonymous route information holding unit 143 stores the searched anonymous route information.
The temporary key generation unit 151 generates a temporary key in response to a request from the anonymous route search request unit 112 or the like. The temporary key is a set of a temporary public key and a temporary secret key.

  The anonymous ID generation unit 152 generates an anonymous ID in response to a request from the anonymous route search request unit 112 or the like. Anonymous ID is identification information set individually for each series of anonymous communication (anonymous route search and anonymous communication using the anonymous route).

  The P2P onion node 100 configured as described above realizes the anonymous communication infrastructure connection authentication function, the anonymous route discovery function, and the anonymous communication function according to the present embodiment. FIG. 5 shows the functional components of the P2P onion node 100, but the other P2P onion nodes 200, 300, 410, 420, 430, 440, and 450 have similar functions.

[Anonymous communication infrastructure connection authentication function]
First, the anonymous communication infrastructure connection authentication function will be described.
FIG. 6 is a diagram illustrating an anonymous communication infrastructure connection authentication function. The anonymous communication infrastructure connection authentication function is such that a certain P2P onion node (P2P onion node 100 in the example of FIG. 6) joins the anonymous communication network 10 with another P2P onion node (P2P onion node in the example of FIG. 6). 200). Note that the P2P onion node 200 that is the connection destination is referred to as a first connection node when viewed from the P2P onion node 100. Here, it is assumed that the P2P onion node 100 knows from the beginning the IP address and port number of the first connection node to be connected. For example, it is assumed that an arbitrarily connectable P2P onion node (a P2P onion node that can be a first connection node) is disclosed in advance.

  RSA encryption is used for encryption methods such as the P2P onion route used in the anonymous communication network 10. It is assumed that each P2P onion node already has an RSA encryption public key, its certificate (public key certificate), a private key, and the like. This public key certificate is used as a membership card for this anonymous communication infrastructure, and is used for authentication for a node to participate in this anonymous communication infrastructure. The public key certificate is stored in the membership card information holding unit 141.

  Here, with reference to FIG. 6, the processing procedure of the anonymous communication infrastructure connection authentication function when the P2P onion node 100 joins the anonymous communication network 10 with the P2P onion node 200 as the first connection node will be described. At this time, the anonymous communication infrastructure connection authentication function is executed between the anonymous communication connection unit 111 in the P2P onion proxy 110 of the P2P onion node 100 and the anonymous communication connection unit 211 in the P2P onion proxy 210 of the P2P onion node 200. Is done.

  [First Processing] The anonymous communication connection unit 111 in the P2P onion node 100 determines the first connection node. Here, the first connection node is an adjacent P2P onion node 200, and there may be a plurality of cases. The IP address or the like of a node that can be designated as the first connection node can be stored in advance in the membership card information holding unit 141. In addition, the user can directly input the IP address of the first connection node or the like through the GUI.

  [Second Processing] The P2P onion proxy (anonymous communication connection unit 111 in the P2P onion proxy 110) of the newly participating node (P2P onion node 100) starts connecting to the first connection node (P2P onion node 200). , Give his fixed public key 142a and membership card 141a.

  [Third Process] The P2P onion proxy (anonymous communication connection unit 211 in the P2P onion proxy 210) of the connected first connection node (P2P onion node 200) also has its own fixed public key 242a and membership card 241a. Pass to the participating node (P2P onion node 100).

  [Fourth Processing] The membership card is confirmed at both the new participating node (P2P onion node 100) and the first connection node (P2P onion node 200). Stop communication if there is a problem such as expiration.

  [Fifth Process] New encrypted nodes (P2P onion node 100) and first connection node (P2P onion node 200) exchange data encrypted with each other's fixed public key. Then, both nodes decrypt the received data and return it to the other party. Each P2P onion node 100, 200 determines that it is an anonymous P2P network-based service use qualification holder if the data transmitted to the other party is correctly decoded and returned. Thereafter, the P2P onion node 100 can participate in the anonymous communication network 10 via the P2P onion node 200. That is, the P2P onion node 100 becomes a node on the anonymous communication infrastructure. As a result, an anonymous communication network 10 as shown in FIG. 2 is formed.

[Anonymous route discovery function]
Next, the anonymous route discovery function will be described using an anonymous route search example when data is transmitted from the P2P onion node 100 to the P2P onion node 300.

  FIG. 7 is a diagram illustrating an anonymous route discovery function. The anonymous route discovery function uses the P2P onion route discovery protocol to anonymously transmit route information from the transmission peer (P2P onion node 100 in the example of FIG. 7) to the reception peer (P2P onion node 300 in the example of FIG. 7). This is a function to collect P2P onion routes from collected route information. The route information includes an identifier and a public key of each Peer that configures a route to the receiving Peer. The P2P onion route discovery protocol constructs a P2P onion route in the following procedure. The anonymous route discovery function is realized by the P2P onion proxies 110, 210, and 310 and the P2P onion routers 120, 220, and 320 of the P2P onion nodes 100, 200, and 300, respectively. In particular, in the transmission Peer (P2P onion node 100), the anonymous route search request unit 112 of the P2P onion proxy 110 executes processing, and in the relay Peer (P2P onion node 200), the route search request relay unit 213 of the P2P onion proxy 210 performs processing. In the receiving Peer (P2P onion node 300), the route search request response unit 314 executes processing.

  In route search, the route search packet 20 is broadcasted from the transmission peer (P2P onion node 100), and the route notification packet 30 is returned from the reception peer (P2P onion node 300) that has received the route search packet 20. .

  FIG. 8 is a diagram illustrating a data structure example of a route search packet. The route search packet 20 includes a message flag 21, a destination (To) 22, a transmission source (From) 23, a destination onion 24, a return onion 25, and temporary key information 26 for reply encryption.

  The message flag 21 indicates the type of packet. In the case of the route search packet 20, information indicating that the packet is a route search broadcast transmission packet is set.

In the destination 22, the destination of the route search packet 20 is set. The destination is indicated by the identification information (public ID) of the received peer published in advance.
In the transmission source 23, the anonymous ID of the transmission peer is set.

The destination onion 24 is information indicating a route to the destination, but is blank in the route search packet 20.
In the return onion 25, a transmission path for returning the route notification packet 30 to the route search packet 20 is set by being encrypted in multiple.

The reply encryption temporary key information 26 is a transmission peer's temporary public key and an encrypted temporary secret key that are used when the route notification packet 30 is returned.
FIG. 9 is a diagram illustrating a data structure example of a route notification packet. The route notification packet 30 includes a message flag 31, a destination (To) 32, a transmission source (From) 33, a destination onion 34, a return onion 35, route information 36, and reply encryption temporary key information 37.

The message flag 31 indicates the type of packet. In the case of the route notification packet 30, information indicating that it is a route search reply packet is set.
In the destination 32, the destination of the route notification packet 30 is set. The destination is the anonymous ID of the transmission peer set in the transmission source 23 of the route search packet 20.

In the transmission source 33, a public ID (public ID) of the reception peer is set.
The destination onion 34 is information indicating a route to the destination. This is a copy of the return onion 25 of the route search packet 20 at the receiving Peer. However, in the destination onion 34, information indicating the past transmission path is deleted every time the packet is relayed.

The return onion 35 is blank in the route notification packet 30.
The route information 36 is information indicating a transmission route for anonymous communication. In the route information, the node ID and the fixed public key of each P2P onion node on the transmission route are set by being encrypted with the fixed public key of the transmission peer. The route information 36 also includes reply encryption temporary key information 26 for the route search packet 20.

In the reply encryption temporary key information 37, the contents of the reply encryption temporary key information 26 of the route search packet 20 are set as they are.
FIG. 10 is a sequence diagram illustrating a processing procedure of the anonymous route discovery function. In the following, the process illustrated in FIG. 10 will be described in order of step number.

  [Step S21] The anonymous route search request unit 112 of the transmission peer (P2P onion node 100) receives a message transmission request from the application 131. It is assumed that the user of the P2P onion node 100 knows in advance the node ID of the P2P onion node 300 that is the receiving peer.

  [Step S22] The anonymous route search request unit 112 generates the route search packet 20. The route search packet 20 includes the public ID of the reception peer, the anonymous ID of the transmission peer, the temporary key (temporary public key and temporary secret key) of the transmission peer, and the like. The public ID of the received Peer is acquired by the application 131 based on an operation input from the user. The anonymous ID of the transmission Peer is acquired from the anonymous ID generation unit 152. The node ID of the transmission Peer is acquired from the general communication function (communication protocol) of the P2P onion node 100. The temporary key of the transmission peer is acquired from the temporary key generation unit 151.

  The return onion 25 of the route search packet 20 is generated from the node ID of the transmission peer and the fixed public key. Specifically, the anonymous route search request unit 112 acquires the fixed public key 142 a from the fixed key holding unit 142. Next, the anonymous route search request unit 112 encrypts the node ID of the transmission Peer with the fixed public key 142a. Then, the anonymous route search request unit 112 sets a return onion 25 as a pair of the encrypted transmission Peer node ID and the unencrypted transmission Peer node ID. At this time, a return flag (in the present embodiment, a symbol “^”) is added to the node ID of the transmission peer that is not encrypted. The return flag indicates a route for returning to the transmission source.

  The reply encryption temporary key information 26 is generated from the temporary key of the transmission peer and the fixed public key 142a. Specifically, the anonymous route search request unit 112 encrypts the temporary private key of the transmission peer with the fixed public key 142a. Then, the anonymous route search request unit 112 sets a pair of the encrypted temporary secret key and the unencrypted temporary public key as the temporary key information 26 for reply encryption.

  [Step S23] The anonymous route search request unit 112 transmits a route search packet by broadcast. In this embodiment, since the node connected to the P2P onion node 100 is only the P2P onion node 200, the first stage is transferred only to the P2P onion node 200 (see FIG. 2).

  [Step S24] When receiving the route search packet 20, the route search request relay unit 213 of the relay Peer (P2P onion node 200) confirms the public ID of the received Peer set in the destination 22. If it is not the route search packet 20 addressed to itself, the process proceeds to step S25 for packet relay. Each P2P onion node holds its public ID in a memory or the like (for example, a membership card information holding unit) in advance.

  [Step S25] The route search request relay unit 213 updates the return onion. Specifically, the route search request relay unit 213 encrypts the return onion 25 in the received route search packet 20 with the fixed public key of the relay Peer. Then, the route search request relay unit 213 adds the node ID (with a return flag) of the relay Peer to the encrypted information, so that a new return onion 25 is obtained.

  [Step S26] The route search request relay unit 213 transmits the route search packet 20 by broadcast. In this embodiment, since four P2P onion nodes 410, 420, 440, and 450 are connected to the P2P onion node 200 in addition to the transmission Peer (P2P onion node 100), these four P2P onion nodes are connected. The route search packet 20 is transmitted to the nodes 410, 420, 440, and 450 (see FIG. 2).

  Thereafter, the route search packet 20 is relayed in each P2P onion node 410, 420, 440, 450, and finally reaches the reception peer (P2P onion node 300). The receiving Peer (P2P onion node 300) that has received the route search packet 20 performs the following processing.

  [Step S27] Upon receiving the route search packet 20, the route search request response unit 314 confirms the destination 22. If it is the route search packet 20 addressed to itself, the process proceeds to step S28 in order to respond.

  The confirmation function of the destination 22 of the route search packet 20 in each P2P onion node is a function shared by the route search request relay unit and the route search request response unit. That is, when the route search packet 20 is received, the confirmation function of the destination 22 operates. If it is addressed to itself, the confirmation result to that effect is transmitted to the route request response unit. Is transmitted to the route search request relay unit.

  [Step S <b> 28] The route search request response unit 314 generates a route notification packet 30. In addition to the information included in the route search packet 20, the route notification packet 30 includes the node ID and fixed public key of the received Peer.

  Specifically, the route search request response unit 314 sets the information of the transmission source 23 of the route search packet 20 to the 30 destinations 32 of the route notification packet. The route search request response unit 314 sets the information of the destination 22 of the route search packet 20 in the 30 transmission source 33 of the route notification packet. The route search request response unit 314 sets the information of the return onion 25 of the route search packet 20 to the 30 destination onions 34 of the route notification packet. The route search request response unit 314 uses the temporary public key of the transmission peer in the return encryption temporary key information 26 of the route search packet 20 to encrypt the pair of the node ID and the fixed public key of the reception peer, and Information 36 is set. Then, the route search request response unit 314 sets information of the return encryption temporary key information 26 of the route search packet 20 in the return encryption temporary key information 37 of the route notification packet.

The route search request response unit 314 passes the generated route notification packet 30 to the anonymous data transmission unit 321 in the P2P onion router 320 of the receiving peer, and requests anonymous communication.
[Step S29] The anonymous data transmission unit 321 determines the transmission destination of the route notification packet 30 based on the return onion 25 of the route search packet 20, and transmits the route notification packet 30 to the transmission destination. Specifically, the return onion 25 includes an unencrypted node ID (node ID of the adjacent P2P onion node) and encrypted information (route to reach the adjacent P2P onion node) Is included). Therefore, the anonymous data transmission unit 321 transmits the route notification packet 30 to the P2P onion node having a node ID that is not encrypted.

The route notification packet 30 is relayed at each P2P onion node. The relay process in the P2P onion node 200 is shown below.
[Step S30] The anonymous data relay unit 222 in the P2P onion router 220 of the relay peer (P2P onion node 200) confirms the destination. Each P2P onion node stores a list of anonymous IDs issued by itself, and determines whether the packet is addressed to itself by comparing the list of anonymous IDs with the destination of the packet. Can do. In the case of the route notification packet 30 addressed to another node, the anonymous data relay unit 222 proceeds with the process to step S31.

  [Step S31] The anonymous data relay unit 222 updates the destination onion 34 of the route notification packet 30. Specifically, the anonymous data relay unit 222 deletes its own node ID added to the destination onion 34 and decrypts the encrypted information using the fixed secret key. Then, the anonymous data relay unit 222 sets the decrypted information as a new destination onion 34.

  [Step S32] The anonymous data relay unit 222 updates the route information 36 of the route notification packet 30. Specifically, the anonymous data relay unit 222 encrypts its node ID and fixed public key with the temporary public key of the transmission peer and stacks it on the route information 36 (in this embodiment, the route information up to that point) After that, the encrypted information is additionally stored). As a result, information (node ID and fixed public key) regarding each P2P onion node on the transmission path is arranged in the route information 36 in the order along the path.

  [Step S33] The anonymous data relay unit 222 determines the transmission destination of the route notification packet 30 based on the destination onion 34, and transmits the route notification packet 30 to the transmission destination. Specifically, the destination onion 34 is encrypted with an unencrypted node ID (node ID of the adjacent P2P onion node) and encrypted information (route to reach the adjacent P2P onion node). Is also included). Therefore, the anonymous data relay unit 222 transmits the route notification packet 30 to the P2P onion node with the node ID that is not encrypted.

As a result, the route notification packet 30 is passed to the P2P onion node 100 which is the transmission peer. In the P2P onion node 100, the following processing is performed.
[Step S34] The anonymous data receiving unit 123 of the P2P onion router 120 of the transmission peer confirms the destination. In the case of the route notification packet 30 addressed to another node, the anonymous data relay unit 222 proceeds with the process to step S31.

  The confirmation function of the destination 32 of the route notification packet in each P2P onion node is a function shared by the anonymous data relay unit and the anonymous data receiving unit. That is, when the route notification packet 30 is actually received, the confirmation function of the destination 32 operates, and if it is addressed to itself, the confirmation result to that effect is transmitted to the anonymous data receiving unit. Is transmitted to the anonymous data relay unit.

  [Step S <b> 35] The anonymous data receiving unit 123 acquires anonymous route information from the route information 36 to the received Peer in the route notification packet 30, and stores it in the anonymous route information holding unit 143. Specifically, the anonymous data receiving unit 123 converts the encrypted information included in the reply encryption temporary key information 37 (the temporary secret key encrypted with the fixed public key 142a) into the fixed secret key 142b. To decrypt. Thereby, a temporary secret key can be acquired. The fixed secret key 142b can be acquired from the fixed key holding unit 142.

  Next, the anonymous data receiving unit 123 decrypts each information included in the route information 36 by using the acquired temporary secret key. As a result, a list of node IDs of the P2P onion nodes on the route to the receiving peer (arranged in order along the route) is obtained. The anonymous data receiving unit 123 stores the acquired list in the anonymous route information holding unit 143 as anonymous route information.

As described above, the search for the anonymous route is completed.
FIG. 11 is a diagram illustrating a transmission path of a route search packet. FIG. 11 shows a state in which the route search packet 20a output from the P2P onion node 100 that is the transmission peer is relayed while being changed in content, and reaches the P2P onion node 300 that is the reception peer.

  The P2P onion node 200 that has received the route search packet 20a output from the P2P onion node 100 generates route search packets 20b and 20e with its own information added to the return onion, and the P2P onion node 410, the P2P onion node 420, etc. Send to.

  The P2P onion node 410 generates a route search packet 20c in which its own information is added to the return onion, and transmits it to the P2P onion node 430. The P2P onion node 430 generates a route search packet 20d with its own information added to the return onion and transmits it to the P2P onion node 300.

  Similarly, the P2P onion node 420 generates a route search packet 20f with its own information added to the return onion, and transmits it to the P2P onion node 430. The P2P onion node 430 generates a route search packet 20g with its own information added to the return onion and transmits it to the P2P onion node 300.

  Thus, the two route search packets 20d and 20g arrive at the P2P onion node 300 that is the receiving peer. That is, the route search packet arrives at the receiving peer through various routes. Therefore, a plurality of route notification packets are also returned.

Here, the internal information of the route search packet transmitted via the P2P onion node 420 will be described in detail.
FIG. 12 is a diagram illustrating a state transition state of the route search packet. In the following description, when other information is shown in parentheses to the right of the key symbol, information obtained by encrypting the information in the parentheses with the key is shown.

  The route search packet 20a passed from the P2P onion node 100 to the P2P onion node 200 includes a message flag “route search broadcast”, a destination (To) “public ID of the node“ X ”, a transmission source (From) node“ A ”. Anonymous ID # 1 ”, destination onion (none), return onion“ ^ Aid + APk (Aid) ”, and temporary key information“ ATPk, APk (ATSk) ”for reply encryption are registered. “^” In the return onion is a return flag. Aid is the node ID of the node “A”. APk is a fixed public key of the node “A”. In the reply encryption temporary key information, ATPk indicates the temporary public key of the node “A”, and ATSk indicates the temporary secret key of the node “A”.

  In the route search packet 20e passed from the P2P onion node 200 to the P2P onion node 420, the return onion is changed to “^ Bid + BPk {^ Aid + APk (Aid)}”. Here, Bid in the return onion is the node ID of the node “B”, and BPk is the fixed public key of the node “B”. Thus, the transmission source is hidden by encrypting the information of the node “A” with the fixed public key of the node “B”.

  In the route search packet 20f passed from the P2P onion node 420 to the P2P onion node 430, the return onion is changed to ^ Did + DPk {^ Bid + BPk {^ Aid + APk (Aid)}}. Here, Did in the return onion is the node ID of the node “D”, and DPk is the fixed public key of the node “D”.

  In the route search packet 20g passed from the P2P onion node 430 to the P2P onion node 300, the return onion is changed to ^ Eid + EPk {^ Did + DPk {^ Bid + BPk {^ Aid + APk (Aid)}}}. Yes. Here, Eid in the return onion is the node ID of the node “E”, and EPk is the fixed public key of the node “E”.

  The P2P onion node 300 that has received the route search packet 20g can recognize that it is addressed to itself by the destination. However, it can be recognized only by the route sent from the P2P onion node 430 having the node name “E”.

Next, the transmission path of the route notification packet transmitted from the P2P onion node 300 will be described.
FIG. 13 is a diagram illustrating a transmission path of a route notification packet. FIG. 13 shows how the two route notification packets 30a and 30e output from the P2P onion node 300 that is the receiving peer are relayed while the contents are changed and reach the P2P onion node 100 that is the transmitting peer. Show.

  The P2P onion node 430 that has received the route notification packet 30a output from the P2P onion node 300 deletes its own information from the return onion, generates a route notification packet 30b with its information added to the route information, and generates P2P Transmit to the onion node 410. The P2P onion node 410 deletes its own information from the return onion, generates a route notification packet 30c with its information added to the route information, and transmits it to the P2P onion node 200. The P2P onion node 200 deletes its own information from the return onion, generates a route notification packet 30d with its own information added to the route information, and transmits it to the P2P onion node 100.

  Also, the P2P onion node 430 that has received the route notification packet 30e output from the P2P onion node 300 deletes its own information from the return onion, and generates a route notification packet 30f with its information added to the route information. , Transmit to the P2P onion node 420. The P2P onion node 420 deletes its own information from the return onion, generates a route notification packet 30g with its information added to the route information, and transmits it to the P2P onion node 200. The P2P onion node 200 deletes its own information from the return onion, generates a route notification packet 30h with its information added to the route information, and transmits it to the P2P onion node 100.

Thus, the two route notification packets 30d and 30h arrive at the P2P onion node 100 that is the transmission peer.
Here, the internal information of the route search packet transmitted via the P2P onion node 420 will be described in detail.

FIG. 14 is a diagram illustrating a state transition state of the route notification packet.
The route notification packet 30e passed from the P2P onion node 300 to the P2P onion node 430 includes a message flag “route search reply”, an address (To) “anonymous ID # 1” of the node “A”, and a source (From) node. “X” public ID ”, destination onion“ ^ Eid + EPk {^ Did + DPk {^ Bid + BPk {^ Aid + APk (Aid)}}} ”, return onion (none), route information“ ATPk (Xid , XPk) ”, reply encryption temporary key information“ ATPk, APk (ATSk) ”, where Xid in the route information is the node ID of the node“ X ”, and XPk is the node“ X ”. This is a fixed public key.

  In the route notification packet 30f passed from the P2P onion node 430 to the P2P onion node 420, the destination onion is changed to ^ Did + DPk {^ Bid + BPk {^ Aid + APk (Aid)}}. As described above, the P2P onion node 430 having the node name “E” deletes its own node ID from the destination onion and decrypts the remaining information with its own fixed secret key. Thereby, the transmission path of the route notification packet is concealed and only the next transfer destination (Did) can be recognized. Further, ATPk (Eid, EPk) is stacked in the route information.

  In the route notification packet 30g passed from the P2P onion node 420 to the P2P onion node 200, the destination onion is changed to ^ Bid + BPk {^ Aid + APk (Aid)}. In addition, ATPk (Did, DPk) is stacked in the route information.

  In the route notification packet 30h passed from the P2P onion node 200 to the P2P onion node 100, the destination onion is changed to ^ Aid + APk (Aid). In addition, ATPk (Bid, BPk) is stacked in the route information.

  The P2P onion node 100 that has received the route notification packet 30h can recognize that it is addressed to itself by the destination. Further, if the route information is decrypted with the temporary secret key, the transmission path (anonymous route) of anonymous communication can be recognized. As a result, the anonymous route information holding unit 143 stores one or more anonymous route information.

  FIG. 15 is a diagram illustrating an example of a data structure in the anonymous route information holding unit. FIG. 15 shows anonymous route information 143a and 143b stored based on the route notification packets 30d and 30h sent back through the two routes shown in FIG.

  In the anonymous route information 143a, “Bid → Cid → Eid → Xid” is set as route information. This indicates that the P2P onion node indicated by the node ID on the left side is closer to the P2P onion node that is the transmission peer. That is, the packet arrives at the P2P onion node 300 with the node ID “Xid” by transferring the packet from the left to the right of the node ID array indicated by the route information.

  The anonymous route information 143a registers the fixed public key “BPk, CPk, EPk, XPk” of each P2P onion node on the route. By using this fixed public key, it is possible to encrypt a packet for performing onion routing.

In the anonymous route information 143b, “Bid → Did → Eid → Xid” and fixed public keys “BPk, DPk, EPk, XPk” of each P2P onion node on the route are registered as route information.
[Anonymous communication function]
Next, the acquired anonymous communication function via the anonymous route will be described.

  FIG. 16 is a conceptual diagram showing an anonymous communication function. FIG. 16 shows an example in which the data packet 40 addressed to the P2P onion node 300 is transmitted from the P2P onion node 100 via the P2P onion node 200. At this time, in the P2P onion node 100 that is the transmission peer, the anonymous data transmission unit 121 executes processing, and in the P2P onion node 200 that is the relay peer, the anonymous data relay unit 222 executes processing, and the P2P onion node that is the reception peer In 300, the anonymous data receiving unit 323 executes the process.

  FIG. 17 is a diagram illustrating a data structure example of a data packet. The data packet 40 includes a message flag 41, a destination (To) 42, a transmission source (From) 43, a destination onion 44, a return & backtrack onion 45, and a payload 46.

The message flag 41 indicates the type of packet. In the case of the data packet 40, information indicating a data communication packet (normal packet) is set.
In the destination 42, the destination of the data packet 40 is set. The destination is the public ID of the receiving peer.

In the transmission source 43, the anonymous ID of the transmission peer is set. This anonymous ID is different from that used when searching for an anonymous route.
The destination onion 44 is information indicating a route to the destination. This is generated based on the anonymous route information acquired from the anonymous route information holding unit 143. The destination onion 44 is obtained by encrypting route information with the public key of each P2P onion node so that only the next node can be recognized at each P2P onion node on the anonymous route.

  The return & backtrack onion 45 is route information indicating a return route and a route when backtrack processing is performed. The backtrack process is a process for transmitting a packet via another route when communication on a planned route is not possible.

The payload 46 is actual data including data obtained by encrypting a message to be transferred with the fixed public key of the receiving peer.
Next, the processing procedure of the anonymous communication function will be described.

FIG. 18 is a sequence diagram illustrating a processing procedure of the anonymous communication function. In the following, the process illustrated in FIG. 18 will be described in order of step number.
[Step S41] The anonymous data transmission unit 121 in the P2P onion router 120 of the P2P onion node 100, which is a transmission peer, accepts a message transmission instruction from the application 131.

  [Step S42] The anonymous data transmission unit 121 selects an anonymous route from the anonymous route information holding unit 143 to the P2P onion node of the transmission partner. At this time, when there are a large number of anonymous routes, a predetermined number of anonymous routes are selected. For example, an anonymous route with a small number of nodes to be relayed is preferentially selected.

  [Step S43] The anonymous data transmission unit 121 generates the data packet 40. The data packet 40 includes information such as the public ID of the received Peer, its own anonymous ID, anonymous route information, message data, and its own temporary key (temporary public key and temporary secret key).

  Specifically, the anonymous data transmission unit 121 sets information indicating a data packet in the message flag 41. In the destination 42, the public ID of the P2P onion node 300 is set. An anonymous ID is set in the transmission source 43. The anonymous ID to be set is newly generated by the anonymous ID generation unit 152.

  In the destination onion 44, the anonymous route information selected from the anonymous route information holding unit 143 is set. At this time, the anonymous data transmission unit 121 sequentially selects the node IDs indicated by the anonymous route information in order from the closest destination node. The anonymous data transmission unit 121 encrypts the first selected node ID (destination node ID) with the fixed public key corresponding to the next selected node ID. Then, the anonymous data transmission unit 121 assigns sequentially selected node IDs to the previously encrypted data, and encrypts the whole with a fixed public key corresponding to the node ID selected next. Then, the anonymous data transmission unit 121 assigns the node ID selected last to the data encrypted immediately before, and the data of the destination onion 44 is generated. As a result, each node that relays the data packet can recognize only the next transmission destination by decrypting the destination onion 44 with its own fixed secret key.

  The return & backtrack onion 45 is set with its own node ID and data obtained by encrypting the node ID with the fixed public key 142a. In the payload 46, information obtained by encrypting predetermined information with the fixed public key of the receiving peer is set in addition to the message data passed from the application 131. The information to be encrypted is information obtained by encrypting the message header, own temporary public key, and own temporary secret key with a fixed public key. Note that the temporary public key and the temporary secret key at this time are newly generated by the temporary key generation unit 151.

[Step S44] The anonymous data transmitter 121 transmits the data packet according to the anonymous route. In this example, it is transmitted to the P2P onion node 200.
[Step S45] The anonymous data relay unit 222 in the P2P onion router 220 of the P2P onion node 200 receives the data packet 40 and confirms the destination 42. If it is addressed to another P2P onion node, the following processing is performed.

  [Step S46] The anonymous data relay unit 222 selects the next route. Specifically, the anonymous data relay unit 222 deletes its own node ID from the destination onion 44. Next, the anonymous data relay unit 222 decrypts the remaining information with its own fixed secret key. As a result, it becomes possible to refer to the set of the next transfer destination node ID and the anonymous route information. One next transfer destination is selected from one or more node IDs indicating the transfer destination. The unselected anonymous route information is used for backtrack processing.

  [Step S47] The anonymous data relay unit 222 updates the destination onion 44. Specifically, a set of the node ID selected in step S46 and the anonymous route corresponding to the node ID is set in the destination onion 44.

[Step S48] The anonymous data relay unit 222 updates the return & backtrack onion 45.
Specifically, the anonymous data relay unit 222 adds a set of the node ID and the anonymous route information not selected in Step S46 to the return & backtrack onion 45 of the data packet 40 for backtrack processing. Then, the anonymous data relay unit 222 encrypts the return & backtrack onion 45 with its own fixed public key and adds its own node ID to the return & backtrack onion 45.

When there is no anonymous route information for backtrack processing, the content of the encrypted information is only the return onion, so a return flag (^) is added to its own node ID.
[Step S49] The anonymous data relay unit 222 transmits the data packet 40. The transmission destination of the data packet 40 is an adjacent P2P onion node indicated by a node ID that can be referred to in the information of the destination onion 44.

  [Step S50] The anonymous data relay unit 222 determines whether the transmitted data packet 40 is correctly transmitted to the next node. If it is transmitted normally, the process is terminated. If the transmission fails, the process proceeds to step S51. If it is known that communication with the destination node is interrupted before the data packet 40 is transmitted, the process proceeds to step S51 without performing the transmission process of step S49.

  [Step S51] The anonymous data relay unit 222 determines whether there is another anonymous route information. When the return flag is set in the return & backtrack onion 45 of the data packet 40 that failed to be transmitted, there is no other anonymous route information (only one is anonymous in the destination onion 44 of the data packet 40 received in step S45). When route information is not included and the return flag is set in the return & backtrack onion 45 of the data packet 40). If there is another anonymous route information, the process proceeds to step S52. If there is no other anonymous route information, the process proceeds to step S55.

  [Step S52] The anonymous data relay unit 222 updates the destination onion 44 of the data packet 40. Specifically, the anonymous data relay unit 222 sets the data decrypted in step S51 as the destination onion 44.

  [Step S53] The anonymous data relay unit 222 updates the return & backtrack onion 45 of the data packet 40. Specifically, the anonymous data relay unit 222 nullifies the contents of the return & backtrack onion 45 of the data packet 40.

  [Step S54] The anonymous data relay unit 222 transmits the data packet 40. The transmission destination of the data packet 40 at this time is the P2P onion node indicated by the node ID that can be recognized by the return onion decoded in step S51.

[Step S55] When there is no other anonymous route information, the anonymous data relay unit 222 transmits the data packet to all the connection destinations recognized at that time by multicast.
[Step S56] When the data packet 40 reaches the P2P onion node 300 that is the receiving peer, the anonymous data receiving unit 323 in the P2P onion router 320 of the P2P onion node 300 confirms the destination. If it is the data packet 40 addressed to itself, the process proceeds to step S57.

[Step S57] The anonymous data receiving unit 323 decrypts the payload 46 with its own fixed secret key.
[Step S58] The anonymous data receiving unit 323 passes the decrypted message header, key information of the transmission peer (temporary public key and encrypted temporary secret key), and the message to the application.

In this way, the data packet 40 is transmitted to the receiving peer. The reply procedure from the reception peer is the same as the transmission procedure of the route notification packet 30.
FIG. 19 is a diagram illustrating a data packet transmission path. As shown in FIG. 19, the data packet 40a output from the P2P onion node 100 has a plurality of P2P onion nodes 200 and 410, which are relay peers, if the transmission route of the anonymous route discovered at the time of route search continues. , 430, the P2P onion node 300, which is the receiving peer, receives the change in content.

  The P2P onion node 200 that has received the data packet 40a transmits the data packet 40b in which the destination onion and the return & backtrack onion are updated to the P2P onion node 410. The P2P onion node 410 that has received the data packet 40b transmits the data packet 40c in which the destination onion and the return & backtrack onion are updated to the P2P onion node 430. The P2P onion node 430 that has received the data packet 40c transmits the data packet 40d in which the destination onion and the return & backtrack onion are updated to the P2P onion node 300.

  FIG. 20 is a diagram illustrating a state transition state of a data packet. The data packet 40a output from the P2P onion node 100 includes the message flag “normal”, the public ID of the destination (To) node “X”, the anonymous ID # 2 of the source (From) node “A”, the destination onion “Bid + BPk {Cid + CPk (Eid + EPk (Xid)), Did + DPk (Eid + EPk (Xid))}”, return & backtrack onion “^ Aid + APk (Aid)”, payload “XPk { Message header, ATPk, APk (ATSk), message data} ”are set.

  In the data packet 40b passed from the P2P onion node 200 to the P2P onion node 410, the destination onion is changed to “Cid + CPk (Eid + EPk (Xid))”, and the return & backtrack onion is “Bid + BPk {^ Aid + APk (Aid), Did + DPk (Eid + EPk (Xid))} ”.

  In the data packet 40c passed from the P2P onion node 410 to the P2P onion node 430, the destination onion is changed to “Eid + EPk (Xid)”, and the return & backtrack onion is “Cid + CPk {Bid + BPk {^ Aid + APk (Aid), Did + DPk (Eid + EPk (Xid))}} ”.

  In the data packet 40d passed from the P2P onion node 430 to the P2P onion node 300, the destination onion is changed to “Xid”, and the return & backtrack onion is “Eid + EPk {Cid + CPk {Bid + BPk {^ Aid + APk (Aid), Did + DPk (Eid + EPk (Xid))}}} ”.

  In this way, every time relay is performed, the encrypted information of the destination onion is decrypted once, and the next transfer destination can be recognized each time. The return & backtrack onion is encrypted every time it is relayed, and the node ID of the relayed P2P onion node is added.

  Here, consider a case where transmission of the data packet 40c from the P2P onion node 410 to the P2P onion node 430 fails. At that time, in the P2P onion node 410, backtrack processing is performed.

  FIG. 21 is a diagram illustrating a data packet transmission path in the backtrack processing. When transmission of the data packet 40c fails in the P2P onion node 410, the data packet 40e is transmitted from the P2P onion node 410 to the P2P onion node 200.

  The P2P onion node 200 transmits the data packet 40f to the P2P onion node 420 which is another route. The P2P onion node 420 transmits the data packet 40g to the P2P onion node 430. The P2P onion node 430 transmits a data packet 40h to the P2P onion node 300.

  FIG. 22 is a diagram illustrating a state transition state of a data packet at the time of backtrack transfer. The data packet 40e transmitted from the P2P onion node 410 includes the message flag “normal”, the public ID of the destination (To) node “X”, the anonymous ID # 2 of the source (From) node “A”, the destination onion “Bid + BPk {^ Aid + APk (Aid), Did + DPk (Eid + EPk (Xid))}”, return & backtrack onion “null”, payload “XPk {message header, ATPk, APk (ATSk), Message data} ”is set.

  In this example, the destination onion includes other anonymous route information and return anonymous route information. Therefore, the P2P onion node 200 sets another anonymous route information as the subsequent destination onion, and sets the return anonymous route information to the return & backtrack onion.

  In the data packet 40f passed from the P2P onion node 200 to the P2P onion node 420, the destination onion is changed to Did + DPk (Eid + EPk (Xid)) ”, and the return & backtrack onion is“ ^ Bid + BPk {^ Aid + APk (Aid)} ”. The return flag is set for the return & backtrack onion because the content is only the return anonymous route information.

  In the data packet 40g passed from the P2P onion node 420 to the P2P onion node 430, the destination onion is changed to “Eid + EPk (Xid)”, and the return & backtrack onion is “^ Cid + CPk {^ Bid + BPk {^ Aid + APk (Aid),}} ”.

  In the data packet 40h passed from the P2P onion node 430 to the P2P onion node 300, the destination onion is changed to “Xid”, and the return & backtrack onion is “^ Eid + EPk {^ Cid + CPk {^ Bid + BPk {^ Aid + APk (Aid)}}} ”.

  In this way, by the backtrack processing, even if the packet transfer through the initially selected anonymous route fails, the data packet can be delivered to the receiving peer via another anonymous route. Such backtrack processing is performed recursively. That is, when transmission by backtracking also fails, data packet backtracking is performed based on another anonymous route.

  Here, when transmission fails in all anonymous routes set as the destination onion of the data packet, the data packet is transferred by multicast. The presence / absence of an unsent anonymous route can be determined by the presence / absence of the return flag of the return & backtrack onion 45.

  For example, when transmission of the data packet 40g from the P2P onion node 420 to the P2P onion node 430 fails, the P2P onion node 420 determines whether or not there is a return flag of the data packet 40g and a return flag of the backtrack onion 45. If the return flag is set, there is no other anonymous route. Therefore, the P2P onion node 420 determines that multicast transmission is necessary.

  FIG. 23 is a diagram illustrating a transmission path of data packets in multicast. If transmission of the data packet 40g fails in the P2P onion node 430, the data packet 40i is transmitted from the P2P onion node 420 to the other P2P onion node 460 (node name “F”) connected at that time. If a path from the P2P onion node 460 to the P2P onion node 300 exists, the data packet is transmitted to the P2P onion node 300. Even in this case, the anonymity of the transmission peer and the reception peer is maintained.

  As described above, the reception peer can reply to the reception message while maintaining the anonymity of the transmission peer. Since the return path is held in the return & backtrack onion, the receiving peer can reply to the transmitting peer by using onion routing using the return onion (anonymous route information in which the return flag “^” is set). Onion routing at the time of reply is the same as transmission except that the reply P2P onion route has only one route. That is, when routing using the P2P onion route fails, the reply message is made to reach by the P2P multicast function. In this case, anonymity is secured.

[Example of application to anonymous bulletin board]
If the above anonymous communication network is applied to an electronic bulletin board, anonymous information exchange among an unspecified number of users can be performed safely.

  FIG. 24 is a diagram illustrating a configuration example of an anonymous communication network applied to an anonymous bulletin board. In the example of FIG. 24, a database (DB) 360 is connected to the P2P onion node 300 in the anonymous communication network 10 to construct a bulletin board system. This bulletin board system is a public DB that is open to the public. In this case, the public ID of the P2P onion node 300 is disclosed in magazines, Internet web pages, and the like.

  Thus, in the anonymous bulletin board function, an anonymous bulletin board (public DB) is mounted on the P2P onion node 300 on the anonymous communication network 10, and information posted on the anonymous bulletin board (public DB) from other P2P onion nodes is used. To do.

A P2P onion node using a bulletin board (public DB) mainly implements the following functions.
1. You can post on an anonymous bulletin board (public DB).
2. You can search for posted data on anonymous bulletin boards (public DB).
3. You can reply to information posted on an anonymous bulletin board (public DB).

  The bulletin board (public DB) is implemented as an application that operates on one P2P onion node 300 on the anonymous communication network 10. Each P2P onion node is provided with a function for notifying the bulletin board (public DB) node (P2P onion node 300) of messages for performing the above three functions via the anonymous communication network 10. The bulletin board (public DB) node (P2P onion node 300) implements a function of storing post data in response to a message notified via the anonymous communication network 10, searching for post data, and returning a search result.

The functions realized by the anonymous bulletin board are shown below.
1. Cannot detect who posted the post (Contributor's secrecy function).
2. The posted information is automatically deleted after a specified time.
3. Cannot detect who made the search (searcher's secret function).
4). It is possible to make a reservation so that even when there is no post data that is searched for when the search is made, notification is made when the post data of interest is posted later.
5). Search reservations are automatically canceled after a specified time.

  The DB 360 can be realized using, for example, XSR (XML Service Registry). XSR is an object database technology owned by Fujitsu Prime Soft Technology. The functions of this software are as follows.

-UP function: A function for saving an object.
An expiration date can be set for the retention period of the object. An expired object is automatically deleted from the XSR.

-LOOKUP function: You can search for the object you are looking for.
It has a function to reserve a search.
-RESPONSE function: Asynchronously notifies the user if there is information that matches the reserved search.

In addition, in order to improve the unlinkability between messages, the anonymous identifier and public key of Peer node are managed as follows.
1. An anonymous identifier is generated using a secret key and a random numerical value. Only you with the private key can be confirmed to be your identifier for the anonymous identifier.
2. Generate a temporary public / temporary private key pair. The temporary private key is encrypted with the public key of the membership card, and is added to the message as reply information together with the temporary public key. The replyer encrypts the reply message with the temporary public key and sends it back. The encrypted data returned can be decrypted only by the person who has the membership card private key.
3. To reveal the anonymity of the anonymous identifier in an emergency situation, bring the anonymous identifier (including the random number used for generation) to the certificate authority in the above “Anonymous Communication Infrastructure Connection Authentication Function” and register all the private keys An anonymous identifier is generated using a random number included in the anonymous identifier by brute force, and a matching secret key is specified.

By installing the anonymous bulletin board having the above configuration on the anonymous communication network 10, anonymous message exchange can be performed.
For example, the user can transmit the data packet 51 including the posted data to the P2P onion node 300 using the P2P onion node 100 and register the posted data in the DB 360. For example, the post data stored in the DB 360 can be searched by sending the data packet 52 including the search request to the P2P onion node 300 using the P2P onion node 420.

  The P2P onion node 300 searches the posted data in the DB 360 in response to the search request, and acquires the search result. Then, the P2P onion node 300 transmits the data packet 53 including the search result to the P2P onion node 420. As a result, the search result is passed to the P2P onion node 420.

  The search result includes anonymous route information (return onion) from the bulletin board node (P2P onion node 300) to the poster P2P onion node, a temporary public key for the poster P2P onion node, and the like. As a result, the P2P onion node that has output the search request can obtain anonymous route information to the poster's P2P onion node, and the message addressed to the poster can be decrypted only by the poster's P2P onion node. Can be encrypted.

  FIG. 25 is a diagram illustrating an example of a data packet including post data. The data packet 51a generated by the P2P onion node 100 includes a message flag “normal”, a public ID of the destination (To) node “X”, a sender (From) “anonymous ID # 3” of the node “A”, a destination Onion “Bid + BPk {Cid + CPk (Eid + EPk (Xid))}”, return & backtrack onion “^ Aid + APk (Aid)”, payload “XPk {message header, ATPk, APk (ATSk), message Data} ”is set. In this example, it is assumed that only one anonymous route information is set in the destination onion for the sake of simplicity.

  When such a data packet 51b arrives at the P2P onion node 300 without any failure during transmission, in the data packet 51b at that time, the destination onion is changed to “Xid”, and the return & backtrack onion Is changed to “Eid + EPk {Cid + CPk {Bid + BPk {^ Aid + APk (Aid)}}}”.

The P2P onion node 300 that has received such a data packet 51 a stores predetermined information in the DB 360.
FIG. 26 is a diagram illustrating an example of a data structure in the DB. In the DB 360, anonymous ID, return onion, reply encryption temporary key information, and message data items are registered in association with each other. For example, based on the data packet 51b, “anonymous ID # 3 of the node“ A ”” is registered in the item of anonymous ID, “Eid + EPk {Cid + CPk {Bid + BPk {^ Aid + APk (Aid)}}} ”is registered.“ ATPk, APk (ATSk) ”is registered in the temporary key information for reply encryption. In the message data item,“ Information such as posting request, upload date / time, and actual data is registered.

Thereafter, the data packet 52 including the search request is transmitted from the P2P onion node 420 to the P2P onion node 300.
FIG. 27 is a diagram illustrating an example of a data packet including a search request. The data packet 52a generated by the P2P onion node 420 includes the message flag “normal”, the public ID of the destination (To) “node” X, the source (From) “anonymous ID # 4” of the node “D”, the destination Onion “Eid + EPk (Xid)”, return & backtrack onion “^ Did + DPk (Did)”, payload “XPk {message header, DTPk, DPk (DTSk), message data}” are set.

  When such a data packet 52a arrives at the P2P onion node 300 without any failure during transmission, in the data packet 52b at that time, the destination onion is changed to “Xid”, and the return & backtrack onion Is changed to “Eid + EPk {^ Did + DPk (Did)}”. Here, the data in the payload is “message header, DPk (DTSk), DTPk, message data (search request, up date and time,...)”.

  The P2P onion node 300 that has received the data packet 52b searches the DB 360 in accordance with an instruction of a search request (a search keyword or the like is indicated). Here, it is assumed that post data posted by the data packet 51b is obtained as a search result. Then, the P2P onion node 300 transmits the data packet 53 including the search result to the P2P onion node 420.

  FIG. 28 is a diagram illustrating an example of a data packet including a search result. The data packet 53a generated by the P2P onion node 300 includes a message flag “request response”, a destination (To) “anonymous ID # 4” of the node “D”, and a transmission source (From) “public ID of the node“ X ””. , Destination onion “Eid + EPk {^ Did + DPk (Did)}”, return & backtrack onion “^ Xid + XPk (Xid)”, payload “XPk {message header, DTPk, DPk (DTSk), message data} "Is set.

  When such a data packet 53a arrives at the P2P onion node 300 without any failure during transmission, the destination onion is changed to “^ Did + DPk (Did)” in the data packet 53b at that time. , The return & backtrack onion is changed to “Eid + EPk {^ Xid + XPk (Xid)}”. Here, the data in the payload is “message header, DPk (DTSk), DTPk {node“ A ”anonymous ID # 3, message data (search request, up date / time,...)”, Eid + EPk {Cid + CPk { Bid + BPk {^ Aid + APk (Aid)}}}} ”. DPk (DTSk) is obtained by encrypting the temporary decryption key of the P2P onion node 420 with a fixed public key. The message data is a search result, and in this example, is the actual data included in the data packet 51a. “Eid + EPk {Cid + CPk {Bid + BPk {^ Aid + APk (Aid)}}}” is a return onion from the P2P onion node 300 to the P2P onion node 100. Also, the node “A” anonymous ID # 3, message data, and Eid + EPk {Cid + CPk {Bid + BPk {^ Aid + APk (Aid)}} (return onion) are the temporary public key of the P2P onion node 420 It is encrypted with (DTPk).

  By decrypting the encrypted data in the payload with the temporary secret key (DTSk) of the P2P onion node 420, the search result can be referred to. The user using the P2P onion node 420 confirms the content of the posted data by referring to the search result. When responding to the posted content, the user inputs a reply message to the P2P onion node 420 and then inputs a reply instruction.

Then, the P2P onion node 420 transmits a data packet including a reply message to the posted data to the P2P onion node 430.
FIG. 29 is a diagram illustrating an example of a data packet including a reply message. The data packet 61 generated by the P2P onion node 420 includes a message flag “reply”, a destination (To) “anonymous ID # 3” of the node “A”, a source “anonymous ID 5” of the node “D”, and a destination onion ”. Eid + EPk {^ Xid + XPk (Xid)}, Eid + EPk {Cid + CPk {Bid + BPk {^ Aid + APk (Aid)}}} ", return & backtrack onion" ^ Did + DPk (Did) “, Payload” message header, DTPk, DPk (DTSk), ATPk (reply message), APk (ATSk) ”are set.

  Here, the destination onion is obtained by connecting the return onion from the P2P onion node 420 to the P2P onion node 300 to the return onion from the P2P onion node 300 to the P2P onion node 100. Each P2P onion node serving as a relay Peer processes in order from the return onion connected in front. Thereby, the anonymous route information from the P2P onion node 420 to the P2P onion node 100 is set as the destination onion.

  “DTPk, DPk (DTSk)” in the payload is temporary key information for reply encryption, and is used for reply from the P2P onion node 100 to the P2P onion node 420. “ATPk (reply message)” indicates that the reply message addressed to the P2P onion node 100 is encrypted with the temporary public key of the P2P onion node 100.

  FIG. 30 is a diagram illustrating a transmission path of a data packet including reply contents. The data packet 61 transmitted from the P2P onion node 420 to the P2P onion node 430 is relayed while receiving the update of the destination onion and the return & backtrack onion. The P2P onion node 430 transmits the data packet 62 to the P2P onion node 300. The P2P onion node 300 transmits the data packet 63 to the P2P onion node 430. The P2P onion node 430 transmits the data packet 64 to the P2P onion node 410. The P2P onion node 410 transmits the data packet 65 to the P2P onion node 200. The P2P onion node 200 transmits the data packet 66 to the P2P onion node 100.

  In this way, anonymous communication between users via the bulletin board becomes possible. In addition, anonymous information can be exchanged among a large number of unspecified users by using a bulletin board to which the present invention is applied. Furthermore, since the node ID and temporary public key are disposable and different values are used for each predetermined procedure, the identity of the posters is concealed for multiple messages posted to the bulletin board by the same poster. be able to.

  By using such a system, even if personal information is exchanged, an individual corresponding to the information can be hidden from a malicious third party. Therefore, such an anonymous bulletin board technology can be applied to preventive medicine / healthcare service (HCS) using network technology. In order to realize the HCS business, the security for the highly sensitive data such as the physical condition and physiological data of the beneficiary is a very important factor. Therefore, when the anonymous bulletin board is applied to the HCS, the physiological data of the user can be registered in the P2P onion node 300 using the P2P onion node 100 while remaining anonymous. Then, doctors using other P2P onion nodes 420 can refer to the registered physiological data, and lifestyle advice and the like can be transmitted to the user anonymously.

  As described above, according to the embodiment of the present invention, before transmitting data, a route to a transmission partner is searched and information (public key of each node) for performing anonymous communication via the route is collected. To do. Therefore, anonymous communication is possible even when the network configuration is dynamically changed. As a result, in an unstable network system such as a P2P network system, when transmitting and receiving data, it is possible to dynamically search a transmission path and to protect the anonymity of the sender and receiver.

  In addition, the data packet for anonymous communication contains information on the anonymous route that is different from the anonymous route being transferred, so if transmission fails, the data is transmitted via another anonymous route. Can be made. This increases the certainty of data transmission.

  In addition, when data transmission via all anonymous routes included in the data packet fails, data transmission via other routes is attempted by multicast. Therefore, when there is another route that does not exist at the time of route search but exists at the time of data transmission, it becomes possible to transmit a packet to the destination P2P onion node via the route.

  Furthermore, in order to increase anonymity during communication, the public key notified to other P2P onion nodes is used as a temporary public key, and the temporary public key is used for each predetermined communication (for example, transmission of a request and response to the request). Since it was made again, even if the contents of the public key are monitored, it cannot be identified whether or not a plurality of packets are output from the same P2P onion node.

  Further, it is determined whether the packet is addressed to itself by the anonymous ID, and the anonymous ID is recreated for each predetermined communication (for example, transmission of request and response to the request). A P2P onion node cannot be identified.

  In the above explanation, the temporary private key of the sending peer encrypted with the fixed public key is included in the reply encryption temporary key information. This is a combination of the temporary public key and the temporary private key. Is a process for not managing by the sending peer.

  Further, the above processing functions can be realized by a computer. In this case, a program describing the processing contents of the functions that the P2P onion node should have is provided. By executing the program on a computer, the above processing functions are realized on the computer. The program describing the processing contents can be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include a magnetic recording device, an optical disk, a magneto-optical recording medium, and a semiconductor memory. Examples of the magnetic recording device include a hard disk device (HDD), a flexible disk (FD), and a magnetic tape. Examples of the optical disc include a DVD (Digital Versatile Disc), a DVD-RAM (Random Access Memory), a CD-ROM (Compact Disc Read Only Memory), and a CD-R (Recordable) / RW (ReWritable). Magneto-optical recording media include MO (Magneto-Optical disc).

  When distributing the program, for example, portable recording media such as a DVD and a CD-ROM in which the program is recorded are sold. It is also possible to store the program in a storage device of a server computer and transfer the program from the server computer to another computer via a network.

  The computer that executes the program stores, for example, the program recorded on the portable recording medium or the program transferred from the server computer in its own storage device. Then, the computer reads the program from its own storage device and executes processing according to the program. The computer can also read the program directly from the portable recording medium and execute processing according to the program. In addition, each time the program is transferred from the server computer, the computer can sequentially execute processing according to the received program.

(Additional remark 1) In the anonymous route search request | requirement method for performing the transmission route search process to a destination in the state which concealed the transmission source with a computer,
When receiving a route search request designating the destination by the destination identifier, the own node identifier that is the identification information of itself is encrypted in a format that can only be decrypted by the user to obtain the anonymous route information for reply,
An arbitrarily generated anonymous identifier, the destination identifier, the return anonymous route information, and a route search packet including a transmission source public key for reply data encryption,
Transmitting the route search packet by broadcast;
An anonymous route search request method characterized by the above.

  (Supplementary note 2) An anonymous route search request according to supplementary note 1, wherein a set of a fixed public key and a fixed secret key is prepared in advance, and the self-node identifier is encrypted using the fixed public key. Method.

  (Supplementary note 3) Each time the route search request is received, a pair of a temporary public key and a temporary secret key is generated, and the generated temporary public key is used as the transmission source public key for reply data encryption, The anonymous route search request method according to appendix 1.

  (Supplementary note 4) Anonymity according to supplementary note 3, wherein a set of a fixed public key and a fixed secret key is prepared in advance, and the temporary secret key is encrypted with the fixed public key and included in the route search packet. Route search request method.

(Supplementary Note 5) A route notification packet including route information obtained by encrypting a pair of a node identifier and a public key of each node on the route from the computer to the destination with the source public key as a response to the route search packet And decrypting the route information with the source private key corresponding to the source public key,
Storing a set of the node identifier and the public key obtained by decryption in a recording device;
The anonymous route search request method according to supplementary note 1, wherein:

(Supplementary Note 6) In an anonymous route search request relay method for relaying a transmission route search request with a transmission source hidden by a computer,
Anonymous identifier of the transmission source, a destination identifier for designating a search partner, anonymized return route information in which a transmission route from the transmission source to the computer is encrypted, and adjacent information that is identification information of an adjacent node on the transmission route Upon receiving a route search packet including a node identifier and a transmission source public key for reply data encryption, the reply anonymous route information and the adjacent node identifier are encrypted in a format that only one can decrypt,
Add own node identifier that is identification information of itself to the route search packet,
Transmitting the route search packet by broadcast;
An anonymous route search request relay method characterized by the above.

  (Supplementary note 7) The anonymous route search request relay method according to supplementary note 6, wherein transmission by the broadcast is performed on a transmission line other than the transmission line to which the route search packet is input.

(Appendix 8) In the anonymous data relay method for relaying anonymous communication via an anonymous route with a computer,
Destination anonymous route information in which the next node identifier indicating the next destination on the anonymous route and the anonymous route information from the next destination to the destination are encrypted with the public key of the computer, from the computer to the source When receiving a data packet including return anonymous route information indicating a transmission route and an adjacent node identifier which is identification information of an adjacent node on the transmission route, the destination anonymous route information is decrypted with a secret key corresponding to the public key. And determining the next node identifier and setting the decrypted data in the data packet as the new destination anonymous route information,
The return anonymous route information and the adjacent node identifier are encrypted with the public key as new return anonymous route information,
Adding the node identifier of the computer to the data packet;
Transmitting the data packet to the node indicated by the next node identifier;
An anonymous data relay method characterized by the above.

  (Supplementary Note 9) When a plurality of pairs of node identifiers of adjacent nodes and the anonymous route information are obtained by decoding the destination anonymous route information, one set is used as the new destination route information, and the other set is backtracked. An additional note characterized by encrypting with the public key together with the return anonymous route information as anonymous route information, and adding the own node identifier of the computer to the encrypted data as the new return anonymous route information 8. The anonymous data relay method according to 8.

  (Supplementary Note 10) If transmission of the data packet fails, the destination anonymous route information of the data packet is replaced with the return anonymous route information when the data packet is received, and the data is transmitted to the node that has transmitted the data packet. The anonymous data relay method according to appendix 8, wherein the packet is returned.

  (Supplementary Note 11) When the destination anonymous route information of the returned data packet is decoded, if the backtrack anonymous route information is included, the node identifier indicated by the backtrack anonymous route information is set as the next node identifier. The anonymous data relay method according to appendix 10, characterized in that:

  (Additional remark 12) When transmission of the data packet fails, if there is no other anonymous route information in any of the destination anonymous route information and the return anonymous route information, each node adjacent to the computer, The anonymous data relay method according to appendix 8, wherein the data packet is transmitted by multicast.

(Supplementary note 13) In an anonymous route search request response method for responding to a transmission route search request in which a transmission source is hidden by a destination computer,
Anonymous identifier of the transmission source, a destination identifier indicating a packet addressed to the computer, anonymized return route information in which a transmission route from the transmission source to the computer is encrypted, and identification information of adjacent nodes on the transmission route When a route search packet including a certain adjacent node identifier and a transmission source public key for reply data encryption is received, the own node identifier which is its own identification information, and a receiving node public key for encrypting information addressed to the own node, Is encrypted with the source public key as route information,
A route notification destination is specified by the anonymous identifier, and a route notification packet including the anonymous route information for reply, the route information, and the source public key is generated,
Sending the route advertisement packet to the node indicated by the adjacent node identifier;
An anonymous route search request response method characterized by the above.

(Supplementary Note 14) In the anonymous route search request program for hiding and searching for the transmission route to the destination,
On the computer,
When receiving a route search request designating the destination by the destination identifier, the own node identifier that is the identification information of itself is encrypted in a format that can only be decrypted by the user to obtain the anonymous route information for reply,
An arbitrarily generated anonymous identifier, the destination identifier, the return anonymous route information, and a route search packet including a transmission source public key for reply data encryption,
Transmitting the route search packet by broadcast;
An anonymous route search request program characterized by causing processing to be executed.

(Supplementary Note 15) In the anonymous route search request relay program for relaying the transmission route search request with the transmission source hidden,
On the computer,
Anonymous identifier of the transmission source, a destination identifier for designating a search partner, anonymized return route information in which a transmission route from the transmission source to the computer is encrypted, and adjacent information that is identification information of an adjacent node on the transmission route Upon receiving a route search packet including a node identifier and a transmission source public key for reply data encryption, the reply anonymous route information and the adjacent node identifier are encrypted in a format that only one can decrypt,
Add own node identifier that is identification information of itself to the route search packet,
Transmitting the route search packet by broadcast;
An anonymous route search request relay program characterized by causing processing to be executed.

(Supplementary Note 16) In the anonymous data relay program for relaying anonymous communication via the anonymous route,
On the computer,
Destination anonymous route information in which the next node identifier indicating the next destination on the anonymous route and the anonymous route information from the next destination to the destination are encrypted with the public key of the computer, from the computer to the source When receiving a data packet including return anonymous route information indicating a transmission route and an adjacent node identifier which is identification information of an adjacent node on the transmission route, the destination anonymous route information is decrypted with a secret key corresponding to the public key. And determining the next node identifier and setting the decrypted data in the data packet as the new destination anonymous route information,
The return anonymous route information and the adjacent node identifier are encrypted with the public key as new return anonymous route information,
Adding the node identifier of the computer to the data packet;
Transmitting the data packet to the node indicated by the next node identifier;
An anonymous data relay program characterized by executing processing.

(Supplementary Note 17) In an anonymous route search request response program for responding to a transmission route search request in which a transmission source is hidden by a destination computer,
On the computer,
Anonymous identifier of the transmission source, a destination identifier indicating a packet addressed to the computer, anonymized return route information in which a transmission route from the transmission source to the computer is encrypted, and identification information of adjacent nodes on the transmission route When a route search packet including a certain adjacent node identifier and a transmission source public key for reply data encryption is received, the own node identifier which is its own identification information, and a receiving node public key for encrypting information addressed to the own node, Is encrypted with the source public key as route information,
A route notification destination is specified by the anonymous identifier, and a route notification packet including the anonymous route information for reply, the route information, and the source public key is generated,
Sending the route advertisement packet to the node indicated by the adjacent node identifier;
An anonymous route search request response program characterized by causing processing to be executed.

(Supplementary note 18) In an anonymous route search requesting device for hiding a transmission source and searching a transmission route to a destination,
When receiving a route search request specifying the destination with the destination identifier, the reply anonymous route information is generated by encrypting the own node identifier, which is its own identification information, in a format that can only be decrypted by itself. Means,
Route search packet generating means for generating a route search packet including an arbitrarily generated anonymous identifier, the destination identifier, the return anonymous route information, and a transmission source public key for reply data encryption,
Transmitting means for transmitting the route search packet by broadcast;
An anonymous route search requesting device characterized by comprising:

(Supplementary note 19) In an anonymous route search request relay device for relaying a transmission route search request in which a transmission source is hidden,
Anonymous identifier of the transmission source, a destination identifier for designating a search partner, anonymized return route information in which a transmission route from the transmission source to the own device is encrypted, and an adjacent information which is identification information of an adjacent node on the transmission route When receiving a route search packet including a node identifier and a transmission source public key for reply data encryption, an encryption means for encrypting the reply anonymous route information and the adjacent node identifier in a format that only one can decrypt. When,
A self-node identifier adding means for adding a self-node identifier that is self-identification information to the route search packet;
Transmitting means for transmitting the route search packet by broadcast;
An anonymous route search request relay device comprising:

(Supplementary note 20) In an anonymous route search request response device for responding to a transmission route search request in which the transmission source is hidden,
Anonymous identifier of the transmission source, a destination identifier indicating a packet addressed to the own device, an anonymous route information for reply in which a transmission route from the transmission source to the own device is encrypted, and identification information of adjacent nodes on the transmission route When a route search packet including a certain adjacent node identifier and a transmission source public key for reply data encryption is received, the own node identifier which is its own identification information, and a receiving node public key for encrypting information addressed to the own node, Route information generating means for generating route information by encrypting with the transmission source public key;
A route notification packet generation means for generating a route notification packet including a route notification destination specified by the anonymous identifier, the anonymous route information for reply, the route information, and the transmission source public key;
Transmitting means for transmitting the route notification packet to the node indicated by the adjacent node identifier;
An anonymous route search request response device characterized by comprising:

(Supplementary Note 21) In an electronic bulletin board providing apparatus for performing anonymous message exchange on a network,
A message to be posted on the bulletin board, first return anonymous route information indicating the first transmission route traced from the sender of the poster, and a first adjacent node identifier which is identification information of an adjacent node on the first transmission route. A registration means for registering the content of the data packet in a database upon receipt of the posted data packet addressed to itself including:
A search condition for the message, second return anonymous route information indicating a second transmission route traced from a sender of the searcher, a second adjacent node identifier which is identification information of an adjacent node on the second transmission route, and Upon receiving a search data packet addressed to itself including a transmission source public key for reply data encryption, search means for searching the database according to the search condition;
Encryption means for encrypting the message detected by the search means, the first return anonymous route information, and the first adjacent node identifier with the source public key;
Packet generating means for generating a response data packet including the encrypted data and the second return route information;
Transmitting means for transmitting the response data packet to the node indicated by the second adjacent node identifier;
An electronic bulletin board providing apparatus, comprising:

(Supplementary Note 22) In a message posting method for posting a message on a computer to an electronic bulletin board for performing anonymous message exchange on a network,
Upon receipt of the message posting request, the computer's own node identifier is encrypted in a format that only one can decrypt, and the own node identifier is added to the encrypted data as return route information,
Destination anonymous route information in which a transmission route for performing anonymous communication with the server provided with the electronic bulletin board is defined, the return anonymous route information, a source public key for reply data encryption, and the message Generate data packets,
Transmitting the data packet to an adjacent node on the route indicated by the destination anonymous route information;
A message posting method characterized by that.

(Supplementary Note 23) In a posted message search method for searching a computer for messages posted on an electronic bulletin board for performing anonymous message exchange on a network,
Upon receiving the search conditions for the message, the computer's own node identifier is encrypted in a format that can only be decrypted by the computer, and the own node identifier is added to the encrypted data as return route information,
Destination anonymous route information in which a transmission route for performing anonymous communication with the server provided with the electronic bulletin board is defined, the return anonymous route information, a source public key for reply data encryption, and the search condition Generates a data packet containing
Transmitting the data packet to an adjacent node on the route indicated by the destination anonymous route information;
Post message search method characterized by this.

(Supplementary Note 24) In an electronic bulletin board providing program for providing an electronic bulletin board for performing anonymous message exchange on a network by a computer,
In the computer,
A message to be posted on the bulletin board, first return anonymous route information indicating the first transmission route traced from the sender of the poster, and a first adjacent node identifier which is identification information of an adjacent node on the first transmission route. Including the posted data packet addressed to itself, register the content of the data packet in the database,
A search condition for the message, second return anonymous route information indicating a second transmission route traced from a sender of the searcher, a second adjacent node identifier which is identification information of an adjacent node on the second transmission route, and When receiving a search data packet addressed to itself including a transmission source public key for reply data encryption, search the database according to the search condition,
The message detected by the search means, the first return anonymous route information, and the first adjacent node identifier are encrypted with the source public key,
Generating a response data packet including the encrypted data and the second return route information;
Transmitting the response data packet to the node indicated by the second adjacent node identifier;
An electronic bulletin board providing program characterized by causing processing to be executed.

It is a conceptual diagram of the invention applied to embodiment. It is a conceptual diagram of an anonymous communication network. It is a figure which shows the hardware structural example of the P2P onion node used for embodiment of this invention. It is a block diagram which shows schematic function structure of a P2P onion node. It is a block diagram which shows the function structure of a P2P onion node. It is a figure which shows an anonymous communication infrastructure connection authentication function. It is a figure which shows an anonymous route discovery function. It is a figure which shows the data structure example of a route search packet. It is a figure which shows the example of a data structure of a route notification packet. It is a sequence diagram which shows the process sequence of an anonymous route discovery function. It is a figure which shows the transmission path | route of a route search packet. It is a figure which shows the state transition state of a route search packet. It is a figure which shows the transmission path | route of a route notification packet. It is a figure which shows the state transition state of a route notification packet. It is a figure which shows the example of a data structure in an anonymous route information holding part. It is a conceptual diagram which shows an anonymous communication function. It is a figure which shows the data structure example of a data packet. It is a sequence diagram which shows the process sequence of an anonymous communication function. It is a figure which shows the transmission path | route of a data packet. It is a figure which shows the state transition state of a data packet. It is a figure which shows the transmission path | route of the data packet in a backtrack process. It is a figure which shows the state transition state of the data packet at the time of backtrack transfer. It is a figure which shows the transmission path | route of the data packet in a multicast. It is a figure which shows the structural example of the anonymous communication network applied to the anonymous bulletin board. It is a figure which shows the example of the data packet containing contribution data. It is a figure which shows the example of a data structure in DB. It is a figure which shows the example of the data packet containing a search request. It is a figure which shows the example of the data packet containing a search result. It is a figure which shows the example of the data packet containing a reply message. It is a figure which shows the transmission path | route of the data packet containing the reply content.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission node 2 Relay node 3 Reception node 10 Anonymous communication network 100, 200, 300, 410, 420, 430, 440, 450 P2P onion node 110, 210, 310 P2P onion proxy 120, 220, 320 P2P onion router

Claims (4)

In the electronic bulletin board providing device for performing anonymous message exchange on the network,
A message to be posted on the bulletin board, first return anonymous route information indicating the first transmission route traced from the sender of the poster, and a first adjacent node identifier which is identification information of an adjacent node on the first transmission route. A registration means for registering the content of the data packet in a database upon receipt of the posted data packet addressed to itself including:
A search condition for the message, second return anonymous route information indicating a second transmission route traced from a sender of the searcher, a second adjacent node identifier which is identification information of an adjacent node on the second transmission route, and Upon receiving a search data packet addressed to itself including a transmission source public key for reply data encryption, search means for searching the database according to the search condition;
Encryption means for encrypting the message detected by the search means, the first return anonymous route information, and the first adjacent node identifier with the source public key;
Packet generation means for generating response data packets including the encrypted data and the second return anonymous route information;
Transmitting means for transmitting the response data packet to the node indicated by the second adjacent node identifier;
An electronic bulletin board providing apparatus, comprising:   In a message posting method for posting a message on a computer to an electronic bulletin board for anonymous message exchange on the network,
  The computer is
  When the message posting request is received, the computer's own node identifier is encrypted in a format that can only be decrypted by itself, and the encrypted node data is added to the encrypted data as return anonymous route information.
  Destination anonymous route information in which a transmission route for performing anonymous communication with the server provided with the electronic bulletin board is defined, the return anonymous route information, a source public key for reply data encryption, and the message Generate data packets,
  Transmitting the data packet to an adjacent node on the route indicated by the destination anonymous route information;
  A message posting method characterized by that.   In a posted message search method for searching a computer for messages posted on an electronic bulletin board for performing anonymous message exchange on a network,
  The computer is
  Upon receiving the search conditions for the message, the computer's own node identifier is encrypted in a format that can only be decrypted by itself, and the encrypted node data is added to the encrypted data as return anonymous route information,
  Destination anonymous route information in which a transmission route for performing anonymous communication with the server provided with the electronic bulletin board is defined, the return anonymous route information, a source public key for reply data encryption, and the search condition Generates a data packet containing
  Transmitting the data packet to an adjacent node on the route indicated by the destination anonymous route information;
  Post message search method characterized by this.   In an electronic bulletin board providing program for providing an electronic bulletin board for performing anonymous message exchange on a network by a computer,
  In the computer,
  A message to be posted on the bulletin board, first return anonymous route information indicating the first transmission route traced from the sender of the poster, and a first adjacent node identifier which is identification information of an adjacent node on the first transmission route. Including the posted data packet addressed to itself, register the content of the data packet in the database,
  A search condition for the message, second return anonymous route information indicating a second transmission route traced from a sender of the searcher, a second adjacent node identifier which is identification information of an adjacent node on the second transmission route, and When receiving a search data packet addressed to itself including a transmission source public key for reply data encryption, search the database according to the search condition,
  The message detected by the search means, the first return anonymous route information, and the first adjacent node identifier are encrypted with the source public key,
  Generating a response data packet including the encrypted data and the second return anonymous route information;
  Transmitting the response data packet to the node indicated by the second adjacent node identifier;
  An electronic bulletin board providing program characterized by causing processing to be executed.

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