JP5665593B2 - Existence proof system, existence proof method and program - Google Patents

Description

  The present invention relates to an existence certification system, an existence certification method, and a program for certifying that two or more mobile phones exist at the same place at the same time.

  Proof of existence means proving that an object (or a person) was present at the same place at a certain time. For example, a person can prove to a third party that he / she has participated in a meeting, or a third person can prove that he / she has been stored in a certain location when there is equipment. The technique regarding is also disclosed (for example, refer nonpatent literature 1).

Ari Juels, “Yoking-Proofs for RFID Tags,” Proceedings of the First International Workshop on Pervasive Computing and Communication Security, IE4.

  However, in the conventional technology, each terminal is independent, and it is impossible to prove existence by grouping a plurality of terminals. Further, it is impossible to prove the York-proofs for RFID disclosed in Non-Patent Document 1 to a third party, and a problem of safety has been pointed out.

  Accordingly, the present invention has been made in view of the above-described problems, and a presence proof system and a presence proof method for safely certifying to a third party that two or more mobile phones existed at the same place at the same time. And to provide a program.

  The present invention proposes the following matters in order to solve the above problems. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.

  (1) The present invention provides a plurality of user terminals (for example, equivalent to the first user terminal 200 and the second user terminal 300 in FIG. 1) and a mediator terminal (for example, equivalent to the mediator terminal 100 in FIG. 1). And a presence proof system in which the plurality of user terminals are grouped and the mediator terminal performs presence proof of the plurality of user terminals.

  According to this invention, a plurality of user terminals are grouped, and the intermediary terminal performs existence proof of the plurality of user terminals. Therefore, it can be proved to a third party that a plurality of user terminals were in the same place at a certain time.

  (2) The present invention is a presence certification system including a first user terminal, a second user terminal, and an intermediary terminal, wherein the mediator terminal sends an existence certification request to the first user terminal. First transmission means (e.g., corresponding to the first transmission unit 110 in FIG. 2), and the first user terminal combines the acquired first time information and its own terminal ID. First electronic signature generating means (for example, corresponding to the first electronic signature generating unit 210 in FIG. 3) for generating an electronic signature calculated using its own private key, and the acquired first time Second transmission means (for example, the second transmission in FIG. 3) returns the information obtained by combining the information and its own terminal ID and the electronic signature created by the first electronic signature creation means to the mediator terminal. Corresponding to the transmission unit 220), and the mediator terminal Comprising a first transfer means (for example, corresponding to the first transfer unit 120 in FIG. 2) for transferring information received from the user terminal to the second user terminal. A second electronic signature creating means (for example, corresponding to the second electronic signature creating unit 320 in FIG. 4) for creating an electronic signature calculated using the private key for these pieces of information, and the mediator terminal The information received from, information obtained by combining the acquired time information and the terminal ID of the second user terminal, and the electronic signature created by the second electronic signature creating means are returned to the mediator terminal. Transmission means (e.g., corresponding to the third transmission unit 330 in FIG. 4), and the mediator terminal transfers information received from the second user terminal to the first user terminal. 2 transfer means (for example, the second transfer unit in FIG. 2) 40), and the first user terminal creates a third electronic signature creating means (for example, the third electronic signature in FIG. 3) for creating a digital signature calculated using its own private key for the received information. ), Information received from the mediator terminal, information obtained by combining the acquired second time information and the terminal ID, and an electronic signature created by the third electronic signature creation means A fourth transmission means (e.g., corresponding to the fourth transmission unit 250 in FIG. 3), and the mediator terminal receives the information received from the first user terminal. There has been proposed a presence proof system characterized by comprising first presence proof information storage means (for example, corresponding to the presence proof information storage unit 160 in FIG. 2) for storing as presence proof information.

  According to this invention, the 1st transmission means of an intermediary terminal sends a presence certification request to a 1st user terminal. The first electronic signature creating means of the first user terminal creates an electronic signature calculated using its own secret key for information obtained by combining the acquired first time information and its own terminal ID. The second transmission means of the first user terminal uses the acquired first time information and its own terminal ID as combined with the electronic signature created by the first electronic signature creation means as an intermediary terminal. Send back. The first transfer means of the mediator terminal transfers the information received from the first user terminal to the second user terminal. The second electronic signature creating means of the second user terminal creates an electronic signature calculated for the received information using its own private key. The third transmission means of the second user terminal includes information received from the mediator terminal, information obtained by combining the time information acquired by the second user terminal and the terminal ID of the second user terminal, The electronic signature created by the electronic signature creating means is returned to the mediator terminal. The second transfer means of the mediator terminal transfers the information received from the second user terminal to the first user terminal. The third electronic signature creating means of the first user terminal creates an electronic signature calculated for the received information using its own private key. The fourth transmission means of the first user terminal includes information received from the mediator terminal, information obtained by combining the second time information acquired by the first user terminal and the terminal ID, and a third electronic signature creation The electronic signature created by the means is returned to the mediator terminal. The first presence certificate information storage means of the mediator terminal stores information received from the first user terminal as presence certificate information. Therefore, it can be safely proved to a third party that the first user terminal and the second user terminal were in the same place at the same time. In addition, since the first user terminal and the second user terminal can perform a proof of existence by performing processing of attaching an electronic signature to information sent from the mediator terminal and returning it, a simple method can be used. Proof of existence can be made.

  (3) According to the present invention, in the presence proof system of (2), a third user terminal (e.g., equivalent to the third user terminal 500 in FIG. 6) is used as the first user terminal and the second user terminal. In the case of joining, the mediator terminal transmits the presence certificate information received from the first user terminal to the third user terminal by fifth transmission means (for example, to the fifth transmission unit 111 in FIG. 7). The third user terminal creates an electronic signature calculated using its own secret key for the information received from the mediator terminal and the information obtained by combining the acquired time information and the terminal ID. 4th electronic signature preparation means (for example, equivalent to the 4th electronic signature preparation part 520 of FIG. 9), information received from the mediator terminal, acquired time information and terminal ID, and the fourth Returns the electronic signature created by the electronic signature creation means Sixth transmission means (e.g., corresponding to the sixth transmission unit 530 in FIG. 9), and the mediator terminal receives the information received from the third user terminal in the first user terminal. A third transfer means for transferring (e.g., corresponding to the third transfer unit 121 in FIG. 7), and the first user terminal receives the received information, the acquired third time information, and a terminal ID; A fifth electronic signature creating means (e.g., corresponding to the fifth electronic signature creating unit 241 in FIG. 8) for creating an electronic signature calculated using its own private key for the information combined with Seventh transmission means for returning information, information obtained by combining the acquired third time information and the terminal ID, and an electronic signature created by the fifth electronic signature creation means to the mediator terminal (for example, FIG. 8 equivalent to the seventh transmission unit 251), and the mediator The terminal is provided with a second presence certificate information storage unit (for example, corresponding to the presence certificate information storage unit 161 in FIG. 7) that stores the information received from the first user terminal as the presence certificate information. The existence proof system is proposed.

  According to this invention, the fifth transmission means of the mediator terminal transmits the presence certificate information received from the first user terminal to the third user terminal. The fourth electronic signature creating means of the third user terminal generates an electronic signature calculated using its own private key for the information received from the mediator terminal and the information obtained by combining the acquired time information and the terminal ID. create. The sixth transmission means of the third user terminal returns the information received from the mediator terminal, the acquired time information, the terminal ID, and the electronic signature created by the fourth electronic signature creation means. The third transfer means of the mediator terminal transfers information received from the third user terminal to the first user terminal. The fifth electronic signature generating means of the first user terminal generates an electronic signature calculated using its own private key for the received information and the information obtained by combining the acquired third time information and the terminal ID. create. The seventh transmission means of the first user terminal intermediaries the received information, the information obtained by combining the acquired third time information and the terminal ID, and the electronic signature created by the fifth electronic signature creation means. Reply to the device. The second presence certificate information storage means of the mediator terminal stores the information received from the first user terminal as presence certificate information. Therefore, even when the number of terminals that perform existence proof increases, it is possible to perform existence proof for a new group including a new terminal. In addition, the third user terminal performs an electronic signature with its own private key on information digitally signed by the first user terminal and the second user terminal, and the first user terminal or the second user terminal is assigned to this information. Since the existence proof can be performed by the process of returning with the electronic signature attached, the presence proof can be performed by a simple method.

  (4) According to the present invention, in the presence certification system according to (2) or (3), the mediator terminal verifies the first time information, the second time information, and the base station information (for example, An existence proof system characterized by having a verification unit 130 in FIG. 2 is proposed.

  According to this invention, the verification means of the mediator terminal verifies the first time information, the second time information, the third time information, and the base station information. Therefore, a transfer attack by an unauthorized third party can be prevented by performing the above verification.

  (5) The present invention includes a certification authority server (for example, equivalent to the certification authority server 400 of FIG. 1) for the presence certification system of (2) to (4), and the certification authority server uses a public key authentication infrastructure. Thus, a presence proof system characterized by verifying the electronic signature is proposed.

  According to the present invention, the certificate authority server is provided, and the certificate authority server verifies the electronic signature using the public key authentication infrastructure. Therefore, it is possible to accurately verify the identity of the electronic signature and the presence or absence of falsification of the contents.

  (6) According to the present invention, in the presence certification system of (2) or (3), the intermediary terminal combines the presence certification information, its own ID, and acquired time information, and the information 6th electronic signature preparation means (for example, equivalent to the electronic signature creation part 170 of FIG. 2) for creating an electronic signature calculated using its own private key, and electronic signature storage means for storing the created electronic signature (For example, corresponding to the electronic signature storage unit 190 in FIG. 2) is proposed.

  According to the present invention, the sixth electronic signature creating means of the mediator terminal uses the combination of the presence certification information, its own ID, and the acquired time information, and its own private key for these information. Create a calculated electronic signature. The electronic signature storage means stores the created electronic signature. Therefore, it is possible to store the electronic signature as evidence of existence while ensuring confidentiality and reliability.

  (7) According to the present invention, in the presence certification system of (6), the mediator terminal publishes an electronic signature stored in the electronic signature storage unit (for example, the electronic signature publishing unit 180 in FIG. 2). The existence proof system characterized by having

  According to the present invention, the electronic signature publication unit of the mediator terminal publishes the electronic signature stored in the electronic signature storage unit. Therefore, it is possible to verify evidence of existence proof by a third party while ensuring confidentiality and reliability.

  (8) The present invention is an existence proof method in an existence proof system comprising a first user terminal, a second user terminal, and an intermediary terminal, wherein the intermediary terminal sends an existence proof request to the first proof request. For the first step (e.g., corresponding to step S101 in FIG. 5) sent to the user terminal and the information obtained by combining the first time information acquired by the first user terminal with its own terminal ID. A second step of creating an electronic signature calculated using its own private key (for example, corresponding to step S102 in FIG. 5), and the first user terminal obtains the acquired first time information and the A third step (for example, corresponding to step S103 in FIG. 5) of returning the information obtained by combining its own terminal ID and the created electronic signature to the mediator terminal; From the user terminal A fourth step (for example, corresponding to step S104 in FIG. 5) for transferring the received information to the second user terminal, and the second user terminal has received its own private key for the received information. A fifth step (for example, corresponding to step S105 in FIG. 5) for creating an electronic signature calculated using the information, information received from the mediator terminal, acquired time information, and the terminal of the second user terminal A sixth step (for example, corresponding to step S106 in FIG. 5) for returning the combined information of the ID and the created electronic signature to the mediator terminal, and the mediator terminal from the second user terminal A seventh step (for example, corresponding to step S107 in FIG. 5) for transferring the received information to the first user terminal, and the first user terminal uses its own secret key for the received information. The An eighth step of creating the calculated electronic signature (for example, corresponding to step S108 in FIG. 5), information received by the first user terminal from the mediator terminal, and acquired second time information; A ninth step (for example, corresponding to step S109 in FIG. 5) for returning the combined information of the terminal ID and the created electronic signature to the mediator terminal, and the mediator terminal from the first user terminal A tenth proof method characterized by comprising a tenth step (for example, corresponding to step S110 in FIG. 5) for storing received information as existence proof information is proposed.

  According to this invention, the mediator terminal sends a presence certificate request to the first user terminal. The first user terminal creates an electronic signature calculated using its own private key for information obtained by combining the acquired first time information and its own terminal ID, and the acquired first time information and Information that combines its own terminal ID and the created electronic signature are returned to the mediator terminal. The mediator terminal transfers information received from the first user terminal to the second user terminal. The second user terminal creates an electronic signature calculated for the received information using its own secret key, and receives the information received from the mediator terminal, the time information acquired by the second user terminal, The information obtained by combining the terminal IDs of the two user terminals and the created electronic signature are returned to the mediator terminal. The mediator terminal transfers information received from the second user terminal to the first user terminal. The first user terminal creates an electronic signature calculated using its own secret key for the received information, and receives the information received from the mediator terminal, the second time information acquired by the first user terminal, The information obtained by combining the terminal ID and the created electronic signature are returned to the mediator terminal. Then, the mediator terminal stores the information received from the first user terminal as presence certification information. Therefore, it can be safely proved to a third party that the first user terminal and the second user terminal were in the same place at the same time. In addition, since the first user terminal and the second user terminal can perform a proof of existence by performing processing of attaching an electronic signature to information sent from the mediator terminal and returning it, a simple method can be used. Proof of existence can be made.

  (9) The present invention relates to the presence certification method according to (8), wherein when the third user terminal joins the first user terminal and the second user terminal, the mediator terminal An eleventh step (for example, corresponding to step S201 in FIG. 10) of transmitting presence certification information received from the terminal to the third user terminal, and information received from the intermediary terminal by the third user terminal A twelfth step (for example, corresponding to step S202 of FIG. 10) for creating an electronic signature calculated using its own private key for information obtained by combining the acquired time information and the terminal ID; 13th step (for example, corresponding to step S203 of FIG. 10) in which the user terminal of the user returns the information received from the broker terminal, the acquired time information and the terminal ID, and the created electronic signature, A 14th step (for example, corresponding to step S204 of FIG. 10) in which the mediator terminal transfers information received from the third user terminal to the first user terminal, and the first user terminal, A fifteenth step (for example, step S205 in FIG. 10) for creating an electronic signature calculated using the private key for the received information and the information obtained by combining the acquired third time information and the terminal ID. And the first user terminal sends back the received information, information obtained by combining the acquired third time information and the terminal ID, and the created electronic signature to the intermediary terminal. Step (for example, corresponding to step S206 in FIG. 10) and a seventeenth step (for example, FIG. 10) in which the mediator terminal stores the information received from the first user terminal as presence certification information 0 corresponds) to step S207 of proposes the existence proof method characterized by comprising a.

  According to this invention, the mediator terminal transmits the presence certificate information received from the first user terminal to the third user terminal. The third user terminal creates an electronic signature calculated using its own private key for the information received from the mediator terminal and the information obtained by combining the acquired time information and the terminal ID, and receives the information from the mediator terminal Information, the acquired time information, the terminal ID, and the created electronic signature are returned. The mediator terminal transfers information received from the third user terminal to the first user terminal. The first user terminal creates an electronic signature calculated using its own secret key for the received information and the information obtained by combining the acquired third time information and the terminal ID. The first user terminal returns the received information, information obtained by combining the acquired third time information and the terminal ID, and the created electronic signature to the mediator terminal. The intermediary terminal stores the information received from the first user terminal as presence certification information. Therefore, even when the number of terminals that perform existence proof increases, it is possible to perform existence proof for a new group including a new terminal. In addition, the third user terminal performs an electronic signature with its own private key on information digitally signed by the first user terminal and the second user terminal, and the first user terminal or the second user terminal is assigned to this information. Since the existence proof can be obtained by the process of returning with the electronic signature attached, the existence proof can be obtained by a simple method.

  (10) The present invention is a program for causing a computer to execute a presence certification method in a presence certification system comprising a first user terminal, a second user terminal, and an intermediary terminal, wherein the mediator terminal comprises: A first step of sending a presence certificate request to the first user terminal (e.g., corresponding to step S101 in FIG. 5), the first user terminal obtains the first time information and its own terminal A second step (for example, corresponding to step S102 in FIG. 5) for creating an electronic signature calculated using its own private key for the information combined with the ID, and the first user terminal A third step (for example, corresponding to step S103 in FIG. 5) for returning the information obtained by combining the first time information and its own terminal ID and the created electronic signature to the mediator terminal; A fourth step (for example, corresponding to step S104 in FIG. 5) in which the mediator terminal transfers the information received from the first user terminal to the second user terminal; and the second user terminal , A fifth step (for example, corresponding to step S105 in FIG. 5) for creating an electronic signature calculated using the private key for the received information, information received from the mediator terminal, A sixth step (for example, corresponding to step S106 in FIG. 5) of returning information obtained by combining the acquired time information and the terminal ID of the second user terminal and the created electronic signature to the mediator terminal; A seventh step (for example, corresponding to step S107 in FIG. 5) in which the mediator terminal transfers information received from the second user terminal to the first user terminal; and the first user terminal And an eighth step (for example, corresponding to step S108 in FIG. 5) of creating an electronic signature calculated using the private key for the received information, and the first user terminal is the mediator terminal 9th step (for example, corresponding to step S109 in FIG. 5), the information obtained by combining the received second time information and the terminal ID, and the created electronic signature to the mediator terminal A program for causing the computer to execute a tenth step (for example, corresponding to step S110 in FIG. 5) in which the intermediary terminal stores information received from the first user terminal as presence certification information. is suggesting.

  According to this invention, the mediator terminal sends a presence certificate request to the first user terminal. The first user terminal creates an electronic signature calculated using its own private key for information obtained by combining the acquired first time information and its own terminal ID, and the acquired first time information and Information that combines its own terminal ID and the created electronic signature are returned to the mediator terminal. The mediator terminal transfers information received from the first user terminal to the second user terminal. The second user terminal creates an electronic signature calculated for the received information using its own secret key, and receives the information received from the mediator terminal, the time information acquired by the second user terminal, The information obtained by combining the terminal IDs of the two user terminals and the created electronic signature are returned to the mediator terminal. The mediator terminal transfers information received from the second user terminal to the first user terminal. The first user terminal creates an electronic signature calculated using its own secret key for the received information, and receives the information received from the mediator terminal, the second time information acquired by the first user terminal, The information obtained by combining the terminal ID and the created electronic signature are returned to the mediator terminal. Then, the mediator terminal stores the information received from the first user terminal as presence certification information. Therefore, it can be safely proved to a third party that the first user terminal and the second user terminal were in the same place at the same time. In addition, since the first user terminal and the second user terminal can perform a proof of existence by performing processing of attaching an electronic signature to information sent from the mediator terminal and returning it, a simple method can be used. Proof of existence can be made.

  (11) The present invention relates to the program of (10), wherein when the third user terminal joins the first user terminal and the second user terminal, the mediator terminal is connected to the first user terminal. An eleventh step (for example, corresponding to step S201 in FIG. 10) for transmitting the received presence certification information to the third user terminal; and information received by the third user terminal from the mediator terminal; A twelfth step (e.g., corresponding to step S202 in FIG. 10) for creating an electronic signature calculated by using its own private key for information obtained by combining the acquired time information and the terminal ID; and the third user A thirteenth step (for example, corresponding to step S203 in FIG. 10) in which the terminal returns the information received from the broker terminal, the acquired time information, the terminal ID, and the created electronic signature; The intermediary terminal transfers the information received from the third user terminal to the first user terminal in a fourteenth step (e.g., corresponding to step S204 in FIG. 10), and the first user terminal A fifteenth step (for example, the step of FIG. 10) of creating an electronic signature calculated using its own private key for the received information and the information obtained by combining the acquired third time information and the terminal ID And the first user terminal sends back the received information, information obtained by combining the acquired third time information and the terminal ID, and the created electronic signature to the mediator terminal. 16 steps (for example, corresponding to step S206 in FIG. 10), and a 17th step (for example, the mediator terminal stores the information received from the first user terminal as presence certification information) 10 and corresponds) to step S207 of proposes a program for causing the computer to execute.

  According to this invention, the mediator terminal transmits the presence certificate information received from the first user terminal to the third user terminal. The third user terminal creates an electronic signature calculated using its own private key for the information received from the mediator terminal and the information obtained by combining the acquired time information and the terminal ID, and receives the information from the mediator terminal Information, the acquired time information, the terminal ID, and the created electronic signature are returned. The mediator terminal transfers information received from the third user terminal to the first user terminal. The first user terminal creates an electronic signature calculated using its own secret key for the received information and the information obtained by combining the acquired third time information and the terminal ID. The first user terminal returns the received information, information obtained by combining the acquired third time information and the terminal ID, and the created electronic signature to the mediator terminal. The intermediary terminal stores the information received from the first user terminal as presence certification information. Therefore, even when the number of terminals that perform existence proof increases, it is possible to perform existence proof for a new group including a new terminal. In addition, the third user terminal performs an electronic signature with its own private key on information digitally signed by the first user terminal and the second user terminal, and the first user terminal or the second user terminal is assigned to this information. Since the existence proof can be obtained by the process of returning with the electronic signature attached, the existence proof can be obtained by a simple method.

  According to the present invention, there is an effect that it is possible to safely prove to a third party that two or more mobile phones exist at the same place at the same time. In addition, the user terminal can perform the existence proof by performing a process of attaching and returning an electronic signature to the transmitted information with its own private key, so that the existence proof can be performed by a simple method. effective.

It is a figure which shows the structure of the presence certification | presentation system which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the mediator terminal which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the 1st user terminal which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the 2nd user terminal which concerns on the 1st Embodiment of this invention. It is a figure which shows the process of the presence certification system which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the presence certification system which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the mediator terminal which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the 1st user terminal which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the 3rd user terminal which concerns on the 2nd Embodiment of this invention. It is a figure which shows the process of the presence certification system which concerns on the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Note that the constituent elements in the present embodiment can be appropriately replaced with existing constituent elements and the like, and various variations including combinations with other existing constituent elements are possible. Therefore, the description of the present embodiment does not limit the contents of the invention described in the claims.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS.

<Configuration of existence proof system>
As shown in FIG. 1, the presence certification system according to the present embodiment includes an intermediary terminal 100, a first user terminal 200, a second user terminal 300, and a certificate authority server 400. In the present embodiment, in order to facilitate understanding, a case will be described in which two terminals, the first user terminal 200 and the second user terminal 300, request an existence certificate. There is no limitation on the number of user terminals for which

  Here, the mediator terminal 100 is a terminal possessed by a reliable mediator, and the first user terminal 200 and the second user terminal 300 form one group and are held by a user who requests a presence certificate. Terminal. Further, the certificate authority server 400 verifies the electronic signature using a public key authentication infrastructure.

<Configuration of broker terminal>
As shown in FIG. 2, the mediator terminal 100 according to the present embodiment includes a first transmission unit 110, a first transfer unit 120, a verification unit 130, a second transfer unit 140, The receiving unit 150 includes an existence certificate information storage unit 160, an electronic signature creation unit 170, an electronic signature disclosure unit 180, and an electronic signature storage unit 190.

  The first transmission unit 110 sends a presence certificate request to the first user terminal 200. The first transfer unit 120 transfers information received from the first user terminal 200 to the second user terminal 300. Before the first transfer unit 120 and the second transfer unit 140 transfer information to the second user terminal 300, the verification unit 130 includes the first time information included in the information, the second time information, Verify time information and base station information.

  The second transfer unit 140 transfers information received from the second user terminal 300 to the first user terminal 200. The first receiving unit 150 includes information transferred from the second transfer unit 140, information obtained by combining the second time information acquired by the first user terminal 200 and the terminal ID, and the first user terminal 200. The third electronic signature creating means receives the electronic signature created.

  The presence certificate information storage unit 160 stores the information received from the first user terminal 200 by the first reception unit 150 as the presence certificate information. The electronic signature creation unit 170 creates an electronic signature calculated using its own private key for information obtained by combining the presence certification information, its own terminal ID, and the acquired time information. The electronic signature publication unit 180 publishes the electronic signature created by the electronic signature creation unit 170 and the information obtained by combining the presence certificate information, the terminal ID of the terminal, and the acquired time information. The electronic signature storage unit 190 stores presence certificate information, its own terminal ID, information obtained by combining the acquired time information, and the electronic signature created by the electronic signature creation unit 170.

<Configuration of first user terminal>
As shown in FIG. 3, the first user terminal 200 according to the present embodiment includes a first electronic signature creation unit 210, a second transmission unit 220, a second reception unit 230, and a third electronic device. The signature generation unit 240 and the fourth transmission unit 250 are configured.

  The first electronic signature creation unit 210 creates an electronic signature calculated using its own private key for information obtained by combining the acquired first time information and its own terminal ID. The second transmission unit 220 returns information obtained by combining the acquired first time information and its own terminal ID and the electronic signature created by the first electronic signature creation unit 210 to the mediator terminal 100.

  The second receiving unit 230 includes information obtained by combining the first time information acquired by the first user terminal 200 and its own terminal ID, the electronic signature generated by the first electronic signature generating unit 210, the first The time information acquired by the second user terminal 300 and the information obtained by combining the terminal ID of the second user terminal 300 and the electronic signature created by the second electronic signature creation unit of the second user terminal 300 are received.

  The third electronic signature creation unit 240 creates an electronic signature calculated using its own private key for the information received by the second reception unit 230. The fourth transmission unit 250 returns the information received by the second reception unit 230 and the electronic signature created by the third electronic signature creation unit 240 to the mediator terminal 100.

<Configuration of second user terminal>
As shown in FIG. 4, the second user terminal 300 according to the present embodiment includes a third receiving unit 310, a second electronic signature creation unit 320, and a third transmission unit 330. .

  The third reception unit 310 includes information obtained by combining the first time information acquired by the first user terminal 200 and the terminal ID of the first user terminal 200, and the first electronic information of the first user terminal 200. The electronic signature created by the signature creation unit is received. The second electronic signature creating unit 320 creates an electronic signature calculated using its own private key for these pieces of information received by the third receiving unit 310.

  Information received by the third receiving unit 310, information obtained by combining the time information acquired by the second user terminal and the terminal ID of the second user terminal, and the electronic created by the second electronic signature creating unit 320 The signature is returned to the mediator terminal 100.

<Processing of existence proof system>
The process of the presence certification system according to the present embodiment will be described with reference to FIG.

  First, the mediator terminal 100 sends a presence certificate request to the first user terminal 200 (step S101). The first user terminal creates an electronic signature calculated using its own secret key for information obtained by combining the acquired first time information and its own terminal ID (step S102). The information obtained by combining the time information 1 and its own terminal ID and the created electronic signature are returned to the mediator terminal 100 (step S103).

  The broker terminal 100 transfers the information received from the first user terminal 200 to the second user terminal 300 (step S104). The second user terminal creates an electronic signature calculated using its own private key for the received information (step S105), and receives the information received from the mediator terminal 100, the acquired time information, and the second information. The information obtained by combining the terminal IDs of the user terminals and the created electronic signature are returned to the mediator terminal 100 (step S106).

  The mediator terminal 100 transfers the information received from the second user terminal 300 to the first user terminal 200 (step S107). The first user terminal 200 creates an electronic signature calculated using its own private key for the received information (step S108), the information received from the mediator terminal 100, the acquired second time information, The information obtained by combining the terminal ID and the created electronic signature are returned to the mediator terminal 100 (step S109). Then, the mediator terminal 100 stores the information received from the first user terminal 200 as presence certification information (step S110).

  As described above, according to this embodiment, it is possible to safely prove to the third party that the first user terminal and the second user terminal were in the same place at the same time. In addition, since the first user terminal and the second user terminal can perform a proof of existence by performing processing of attaching an electronic signature to information sent from the mediator terminal and returning it, a simple method can be used. Proof of existence can be made.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to FIGS.

<Configuration of existence proof system>
As shown in FIG. 6, the presence certification system according to the present embodiment includes an intermediary terminal 100, a first user terminal 200, a second user terminal 300, a certificate authority server 400, and a third user terminal. 500. That is, in the present embodiment, in the first embodiment, the third user terminal 500 is newly added to the group of the first user terminal 200 and the second user terminal 300 for which the existence proof has been made, and the existence proof. Is related to In addition, it is possible to increase the number of user terminals in the group by repeatedly executing the processing shown below. Further, in the present embodiment, the presence proof is performed using the first user terminal 200, but the presence proof may be performed using the second user terminal 300.

<Configuration of broker terminal>
As illustrated in FIG. 7, the mediator terminal 100 according to the present embodiment includes a fifth transmission unit 111, a third transfer unit 121, a fourth reception unit 151, and a presence certificate information storage unit 161. It is configured.

  The fifth transmission unit 111 transmits the presence certificate information received from the first user terminal 200 to the third user terminal 500. The third transfer unit 121 includes, in the first user terminal, presence certificate information, time information and terminal ID acquired by the third user terminal 500, and a fourth electronic signature creation unit of the third user terminal 500. Transfer the electronic signature created by. The presence certificate information storage unit 161 includes presence certificate information, time information and a terminal ID acquired by the third user terminal 500, an electronic signature created by the fourth electronic signature creation unit of the third user terminal 500, The information obtained by combining the third time information acquired by the first user terminal 200 and the terminal ID and the electronic signature created by the fifth electronic signature creation unit of the first user terminal 200 are stored as existence certification information. To do.

<Configuration of first user terminal>
As illustrated in FIG. 8, the first user terminal 200 according to the present embodiment includes a fourth reception unit 231, a fifth electronic signature creation unit 241, and a seventh transmission unit 251. .

  The fourth receiving unit 231 receives the presence certification information, the time information acquired by the third user terminal 500, the terminal ID, and the electronic signature generated by the fourth electronic signature generating unit of the third user terminal 500. Receive. The fifth electronic signature creation unit 241 creates an electronic signature calculated using its own private key for the information received by the fourth reception unit 231 and the information obtained by combining the acquired time information and the terminal ID. . The seventh transmission unit 251 returns the electronic signature created by the fifth electronic signature creation unit 241 to the mediator terminal 100.

<Configuration of third user terminal>
As shown in FIG. 9, the third user terminal 500 according to the present embodiment includes a fifth reception unit 510, a fourth electronic signature creation unit 520, and a sixth transmission unit 530. .

  The fifth reception unit 510 receives the presence certificate information received from the first user terminal 200. The fourth electronic signature creating unit 520 creates an electronic signature calculated using its own private key for the information received from the fifth receiving unit 510 and the information obtained by combining the acquired time information and the terminal ID. . The sixth transmission unit 530 returns the information received from the fifth reception unit 510, the acquired time information, the terminal ID, and the electronic signature created by the fourth electronic signature creation unit 520.

<Processing of existence proof system>
The process of the presence certification system according to the present embodiment will be described with reference to FIG.

  First, the mediator terminal 100 transmits the presence certificate information received from the first user terminal 200 to the third user terminal 500 (step S201). The third user terminal 500 creates an electronic signature calculated by using its own secret key for the information received from the mediator terminal 100 and the information obtained by combining the acquired time information and the terminal ID (step S202). The information received from the mediator terminal 100, the acquired time information, the terminal ID, and the created electronic signature are returned (step S203).

  The mediator terminal 100 transfers the information received from the third user terminal 500 to the first user terminal 200 (step S204). The first user terminal 200 creates an electronic signature calculated using its own private key for the received information and the information obtained by combining the acquired third time information and the terminal ID (step S205). The received information, information obtained by combining the acquired third time information and the terminal ID, and the created electronic signature are returned to the mediator terminal 100 (step S206). Then, the mediator terminal 100 stores the information received from the first user terminal 200 as presence certification information (step S207).

  As described above, according to the present embodiment, even when the number of terminals that perform existence verification increases, it is possible to perform existence verification for a new group including a new terminal. In addition, the third user terminal performs an electronic signature with its own private key on information digitally signed by the first user terminal and the second user terminal, and the first user terminal or the second user terminal is assigned to this information. Since the existence proof can be obtained by the process of returning with the electronic signature attached, the existence proof can be obtained by a simple method.

  The existence proof system of the present invention can be realized by recording the processing of the existence proof system on a computer-readable recording medium, reading the program recorded on the recording medium into the existence proof system, and executing it. . The computer system here includes an OS and hardware such as peripheral devices.

  Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW (World Wide Web) system is used. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  The embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiments, and includes designs and the like that do not depart from the gist of the present invention.

100; mediator terminal 110; first transmission unit 111; fifth transmission unit 120; first transfer unit 121; third transfer unit 130; verification unit 140; second transfer unit 150; first reception Unit 151; fourth receiving unit 160; presence certificate information storage unit 161; presence certificate information storage unit 170; electronic signature creation unit 180; electronic signature disclosure unit 190; electronic signature storage unit 200; first user terminal 210; 1st electronic signature creation part 220; 2nd transmission part 230; 2nd reception part 231; 4th reception part 240; 3rd electronic signature creation part 241; 5th electronic signature creation part 250; 4th 7th transmission unit 300; 2nd user terminal 310; 3rd reception unit 320; 2nd electronic signature creation unit 330; 3rd transmission unit 400; CA station server 500; 3rd user Terminal 510; fifth Receiving unit 520; fourth digital signature creation section 530; transmitting portion of the sixth

Claims (7)

An existence proof system comprising a first user terminal, a second user terminal, and an intermediary terminal,
The intermediary terminal is
First transmission means for sending a presence certificate request to the first user terminal;
The first user terminal is
First electronic signature creation means for creating an electronic signature calculated using its own private key for information obtained by combining the acquired first time information and its own terminal ID;
Second transmission means for returning information obtained by combining the acquired first time information and its own terminal ID and the electronic signature created by the first electronic signature creation means to the mediator terminal;
With
The intermediary terminal is
Comprising first transfer means for transferring information received from the first user terminal to the second user terminal;
The second user terminal is
Electronic information calculated by using the private key for the information obtained by combining the acquired first time information and the terminal ID of the first user terminal, and the electronic signature created by the first electronic signature creating means A second electronic signature creation means for creating a signature;
Information obtained by combining the first time information received by the first user terminal received from the mediator terminal and the terminal ID of the first user terminal, an electronic signature created by the first electronic signature, and an acquired time Information that combines information and the terminal ID of the second user terminal, and third transmitting means for returning the electronic signature created by the second electronic signature creating means to the mediator terminal;
With
The intermediary terminal comprises second transfer means for transferring information received from the second user terminal to the first user terminal;
The first user terminal is
Third electronic signature creation means for creating an electronic signature calculated using the private key of the received information;
The information received from the mediator terminal, the information obtained by combining the acquired second time information and the terminal ID, and the electronic signature created by the third electronic signature creation means are returned to the mediator terminal. Means for sending
With
The intermediary terminal comprises first presence certificate information storage means for storing the information received from the fourth transmission means as presence certificate information;
When a third user terminal joins the first user terminal and the second user terminal,
The intermediary terminal is
As the fourth the information and presence certification information the electronic signature received from the transmitting means of the first user terminal comprises a fifth transmission means for transmitting to said third user terminal,
The third user terminal is
A fourth electronic signature creating means for creating an electronic signature calculated using its own private key for information obtained by combining the information received from the mediator terminal and the acquired time information and the terminal ID;
Information received from the intermediary terminal; acquired time information; terminal ID; and sixth transmission means for returning an electronic signature created by the fourth electronic signature creation means;
With
The intermediary terminal is
Comprising a third transfer means for transferring the information received from the third user terminal to the first user terminal;
The first user terminal is
First, an electronic signature calculated using its own private key is created for the information transferred from the third transfer means of the intermediary terminal and the information obtained by combining the acquired third time information and the terminal ID. 5 electronic signature creation means;
The information transferred from the third transfer means of the intermediary terminal, the information obtained by combining the acquired third time information and the terminal ID, and the electronic signature created by the fifth electronic signature creation means are used as the intermediary. A seventh transmission means for replying to the person terminal;
With
The intermediary terminal is
A presence proof system comprising: second presence certificate information storage means for storing information transmitted from the seventh transmission means of the first user terminal as presence certificate information. The intermediary terminal comprises verification means for verifying the first time information, second time information, third time information, and base station information of the first user terminal. The existence proof system according to claim 2 or claim 1 . An authentication station server, the intermediary terminal, existence proof system according to claim 1 or claim 2 wherein the authentication station server using public key authentication infrastructure, characterized by verifying the electronic signature. A sixth electronic signature in which the intermediary terminal creates information obtained by combining the presence certification information, its own ID and the acquired time information, and an electronic signature calculated using the private key for the information; Creating means;
Electronic signature storage means for storing the created electronic signature;
The presence proof system according to claim 1 , further comprising: 5. The presence certification system according to claim 4 , wherein the intermediary terminal includes an electronic signature publishing unit that publishes an electronic signature stored in the electronic signature storage unit. An existence proof method in an existence proof system comprising a first user terminal, a second user terminal, and an intermediary terminal,
A first step in which the intermediary terminal sends a presence certificate request to the first user terminal;
A second step in which the first user terminal creates an electronic signature calculated using its own private key for information obtained by combining the acquired first time information and its own terminal ID;
A third step in which the first user terminal returns information obtained by combining the acquired first time information and its own terminal ID and the created electronic signature to the mediator terminal;
A fourth step in which the mediator terminal transfers information received from the first user terminal to the second user terminal;
The second user terminal uses its own secret key for the information obtained by combining the acquired first time information and the terminal ID of the first user terminal, and the electronic signature created in the second step. A fifth step of creating an electronic signature calculated using:
Information obtained by combining the first time information received by the first user terminal received from the mediator terminal and the terminal ID of the first user terminal, an electronic signature created by the first electronic signature, and an acquired time A sixth step of returning the information obtained by combining the information and the terminal ID of the second user terminal and the electronic signature created by the second electronic signature creating means to the mediator terminal;
A seventh step in which the mediator terminal transfers information received from the second user terminal to the first user terminal;
An eighth step in which the first user terminal creates an electronic signature calculated using its own private key for the received information;
The intermediary terminal includes information received by the first user terminal from the intermediary terminal, information obtained by combining the acquired second time information and the terminal ID, and the electronic signature created in the second step. A ninth step to reply to
A tenth step in which the intermediary terminal stores the received information as presence certification information transmitted and received by the first user terminal in the ninth step;
When a third user terminal joins the first user terminal and the second user terminal,
The intermediary terminal, as the ninth Existence information the information and the electronic signature received in step of the first user terminal, an eleventh step of transmitting to the third user terminal,
A twelfth step in which the third user terminal creates an electronic signature calculated by using its own private key for information obtained by combining the information received from the mediator terminal, the acquired time information and the terminal ID; When,
A thirteenth step in which the third user terminal returns the information received from the broker terminal, the acquired time information and terminal ID, and the electronic signature created in the twelfth step;
A 14th step in which the mediator terminal transfers information received from the third user terminal to the first user terminal;
The first user terminal uses its own secret key for the information transferred in the fourteenth step from the intermediary terminal and the information obtained by combining the acquired third time information and the terminal ID. A fifteenth step of creating a calculated electronic signature;
The first user terminal receives the information transferred in the fourteenth step from the broker terminal, the information obtained by combining the acquired third time information and the terminal ID, and the created electronic signature with the broker. A sixteenth step of replying to the terminal;
A seventeenth step in which the intermediary terminal stores the information transmitted in the sixteenth step as presence certification information;
An existence proving method characterized by comprising: A program for causing a computer to execute a presence proof method in a presence proof system comprising a first user terminal, a second user terminal, and an intermediary terminal,
A first step in which the intermediary terminal sends a presence certificate request to the first user terminal;
A second step in which the first user terminal creates an electronic signature calculated using its own private key for information obtained by combining the acquired first time information and its own terminal ID;
A third step in which the first user terminal returns information obtained by combining the acquired first time information and its own terminal ID and the created electronic signature to the mediator terminal;
A fourth step in which the mediator terminal transfers information received from the first user terminal to the second user terminal;
The second user terminal uses its own secret key for the information obtained by combining the acquired first time information and the terminal ID of the first user terminal, and the electronic signature created in the second step. A fifth step of creating an electronic signature calculated using:
Information obtained by combining the first time information received by the first user terminal received from the mediator terminal and the terminal ID of the first user terminal, an electronic signature created by the first electronic signature, and an acquired time A sixth step of returning the information obtained by combining the information and the terminal ID of the second user terminal and the electronic signature created by the second electronic signature creating means to the mediator terminal;
A seventh step in which the mediator terminal transfers information received from the second user terminal to the first user terminal;
An eighth step in which the first user terminal creates an electronic signature calculated using its own private key for the received information;
The intermediary terminal includes information received by the first user terminal from the intermediary terminal, information obtained by combining the acquired second time information and the terminal ID, and the electronic signature created in the second step. A ninth step to reply to
A tenth step in which the intermediary terminal stores the received information as presence certification information transmitted and received by the first user terminal in the ninth step;
When a third user terminal joins the first user terminal and the second user terminal,
The intermediary terminal, as the ninth Existence information the information and the electronic signature received in step of the first user terminal, an eleventh step of transmitting to the third user terminal,
A twelfth step in which the third user terminal creates an electronic signature calculated by using its own private key for information obtained by combining the information received from the mediator terminal, the acquired time information and the terminal ID; When,
A thirteenth step in which the third user terminal returns the information received from the broker terminal, the acquired time information and terminal ID, and the electronic signature created in the twelfth step;
A 14th step in which the mediator terminal transfers information received from the third user terminal to the first user terminal;
The first user terminal uses its own secret key for the information transferred in the fourteenth step from the intermediary terminal and the information obtained by combining the acquired third time information and the terminal ID. A fifteenth step of creating a calculated electronic signature;
The first user terminal receives the information transferred in the fourteenth step from the broker terminal, the information obtained by combining the acquired third time information and the terminal ID, and the created electronic signature with the broker. A sixteenth step of replying to the terminal;
A seventeenth step in which the intermediary terminal stores the information transmitted in the sixteenth step as presence certification information;
A program that causes a computer to execute.

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