Electronic signature device and electronic signature utilization system

Abstract

To provide a reliable electronic signature device, an electronic signature utilization system, and an electronic signature generation method.SOLUTION: An electronic signature device 20 includes a control unit and a storage unit used by the control unit, the control unit acquires biometric information D20 of a user U1 who performs electronic signature, generates a personal private key K21 and a personal public key K22 by one-way conversion from the acquired biometric information, generates electronic signature D21 by encrypting the verification information D11 generated by an electronic document issuing server 10 and stored in the storage unit by using the personal secret key, converts the generated electronic signature into a displayable code D22, and causes a predetermined medium 81 to display the code. As a result, the user's biometric information is used to encrypt the verification information and is not used as the verification information, such that the user's biometric information is not leaked from the verification information, thereby improving reliability.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electronic signature device, an electronic signature utilization system, and an electronic signature generation method. [Background technology]

[0002] In recent years, digitalization and cloud computing have progressed, with documents being digitized and stamps being eliminated. However, paper documents still play an important role in a situation known as the digital divide, where people who can use information and communications technology coexist with those who cannot.

[0003] On the other hand, biometric information is increasingly being used for identity authentication instead of basic authentication using a user ID and password (Patent Documents 1, 2, and 3).

[0004] In the technology described in Patent Document 1, the fingerprint information of the user who purchased the ticket is read by a compatible terminal to generate a hash value, which is then sent to the ticket center for storage. When the ticket is used, the fingerprint information of the user is read again to generate a hash value, which is then sent to the ticket center for verification.

[0005] In the technology described in Patent Document 2, the user's fingerprint information is encrypted with an event ID key obtained from the ticket issuing server to generate a two-dimensional code, and when the ticket is used, the user's fingerprint information is read again and compared with the fingerprint information restored from the two-dimensional code.

[0006] The technology described in Patent Document 3 realizes a biometric signature using a feature vector extracted from actual biometric information by converting vector X in a vector space having an arbitrary distance structure (Lp distance) into vector Y having an L∞ distance structure. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2006-24062 A [Patent Document 2] JP 2017-117301 A [Patent Document 3] Patent No. 6216567 Summary of the Invention [Problem to be solved by the invention]

[0008] Both Patent Documents 1 and 2 directly use a user's biometric information as information for identity authentication, and therefore cannot eliminate the possibility of the biometric information being leaked. Since biometric information is information that can identify a person's health condition, race, etc., and is information that remains unchanged throughout a person's life, there is a high risk if it is leaked to the outside. Therefore, when using biometric information for identity authentication, safety must be given top priority. On the other hand, if the processing cost (time required for processing) becomes too high when using biometric information for identity authentication, convenience decreases.

[0009] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a highly reliable electronic signature device, an electronic signature utilization system, and an electronic signature generation method. [Means for solving the problem]

[0010] In order to solve the above problems, an electronic signature device according to one aspect of the present invention has a control unit and a memory unit used by the control unit, and the control unit acquires biometric information of a user who will sign an electronic signature, generates a personal private key and a personal public key by performing one-way conversion from the acquired biometric information, generates an electronic signature by encrypting verification information generated by an electronic document issuing server and stored in the memory unit using the personal private key, converts the generated electronic signature into a displayable code, and displays the code on a specified medium. Effect of the Invention

[0011] According to the present invention, the biometric information of the user is used to encrypt the verification information, but is not used as the verification information. Therefore, the biometric information of the user will not be leaked from the verification information, and security is improved.

Brief Description of the Drawings

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Modes for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, as described below, personal authentication can be performed without going through the electronic document issuing server 10. In the electronic signature utilization system 1 according to this embodiment, when the user U1 causes the electronic document issuing server 10 to issue the electronic document D10, the electronic signature device 20 generates a pair of a personal secret key K21 and a personal public key K22 from the user's biometric information by one-way conversion. The electronic signature device 20 encrypts the verification information D11 containing the electronic document D10 with the personal secret key K21 to generate an electronic signature D21. The electronic signature D21 is converted into a two-dimensional code D22 and printed on a predetermined area of a predetermined medium 80 by the display output device 30. The signature verification device 40 reads and decodes the two-dimensional code D22 to extract the electronic signature D21. The signature verification device 40 reads the biometric information of the user U1 to generate a pair of a personal secret key and a personal public key, and decrypts the electronic signature D21 using the personal public key.

[0014] The electronic document D10 is, for example, a ticket, a medical examination ticket, a medical record, an examination ticket, an application form, a report, a residence certificate, a security, a check, a passport, a right document such as land, a contract, a receipt, a ticket, a commuter pass, a book, etc. Hereinafter, the ticket will be taken as an example of the electronic document D10 for explanation. The biometric information D20 is, for example, fingerprint information, vein information, iris information of the pupil, etc. Hereinafter, the finger vein information will be taken as an example of the biometric information D20 for explanation.

[0015] FIG. 1 is an overall configuration diagram of the electronic signature utilization system 1. The electronic signature utilization system 1 includes, for example, an electronic document issuing server 10, a signature device 20, and a signature verification device 40. A plurality of each of the signature device 20 and the signature verification device 40 may be provided. The hardware configuration and functional configuration of each device 10, 20, 40 will be described later.

[0016] When the user U1 purchases an electronic document D10 such as a ticket from the electronic document issuing server 10, the user U1 registers the biometric information D20 in the signature device 20. The signature device 20 acquires the biometric information D20 of the user U1 from a biometric information scanner 52 (see FIG. 3) that reads the biometric information and outputs it as digital data (S11).

[0017] The signature device 20 generates a personal private key K21 in a form that cannot be restored from the biometric information D20 by unidirectionally converting the biometric information D20 of the user U1 (S12), and generates a personal public key K22 from the personal private key K21 (S13). Unidirectional conversion is a process that uses a function in which the forward operation of converting the biometric information D20 into the personal private key K21 is easy, but the reverse operation of converting the personal private key K21 into the biometric information D20 is extremely difficult.

[0018] The electronic document issuing server 10 stores a server private key K11 and a server public key K12. In response to a request from the user U1 (specifically, in response to a request from the signature device 20 operated by the user U1), the electronic document issuing server 10 prepares an electronic document D10 (S14), and generates verification information D11 by encrypting the electronic document D10 with the server private key K11 (S15). The electronic document issuing server 10 transmits the verification information D11 to the signature device 20 (S16).

[0019] The signature device 20 obtains an electronic signature D21 by encrypting the verification information D11 obtained from the electronic document issuing server 10 with the personal private key K21 (S17). Since this electronic signature D21 is derived from the biometric information D20, it can also be called a biometric signature D21.

[0020] The signature device 20 obtains the server public key K12 from the electronic document issuing server 10, and generates a two-dimensional code D22 by adding the server public key K12 to the electronic signature D21 and encoding it (S18).

[0021] The signature device 20 transmits the generated two-dimensional code D22 to the printer 30 and causes the two-dimensional code D22 to be printed on the ticket paper 80 (S19). Thereby, a ticket 81 with the two-dimensional code D22 printed thereon is generated.

[0022] The printer 30 can also be called, for example, a "display output device". The ticket paper 80 is an example of a "predetermined medium". The ticket paper 80 only needs to be able to print the two-dimensional code D22, and it can be a thin plate such as plastic, ceramic, or metal in addition to ordinary paper. The two-dimensional code D22 is printed in the empty area of the ticket 81. The empty area of the ticket 81 is the area other than the main printing area where part or all of the data of the electronic document D10 is printed on both sides of the ticket 81. From the perspective of enhancing visibility during signature verification, it is preferable that the two-dimensional code D22 is printed in the empty area existing on the same surface as the main printing area. Nevertheless, the two-dimensional code D22 may be printed on the surface opposite to the main printing area.

[0023] The two-dimensional code D22 may be printed on an electronic medium as the "predetermined medium". The electronic medium is, for example, image data that can be displayed on the display screen of a tablet terminal or a portable information terminal (including a smartphone).

[0024] The user U1 goes to a predetermined place where tickets such as an event venue are used and presents the ticket 81. The ticket 81 is read by the two-dimensional code scanner 60 and sent as digital data to the signature verification device 40 (S20). When the predetermined medium is an electronic medium such as image data, the two-dimensional code scanner 60 may be configured as, for example, a digital camera.

[0025] The signature verification device 40 decodes the two-dimensional code D22 received from the scanner 60 (S21) and obtains the electronic signature D21 and the server public key K12. On the other hand, the signature verification device 40 obtains the biometric information D20 of the user U1 (S22), generates a personal private key K21 by one-way conversion of the obtained biometric information D20 (S23), and generates a personal public key K22 from the personal private key K21 (S24). Then, the signature verification device 40 uses the personal public key K22 to decrypt the electronic signature D21 obtained from the two-dimensional code D22 and obtains the verification information D11 (S25).

[0026] The fact that the electronic signature D21 obtained from the two-dimensional code D22 of the ticket 81 can be decrypted with the personal public key K22 based on the biometric information D20 newly obtained from the user U1 proves that the user U1 who created the electronic signature D21 with the signature device 20 and the user U1 who is being verified by the signature verification device 40 are the same person.

[0027] The signature verification device 40 acquires the electronic document D10 by decrypting the verification information D11 obtained from the two-dimensional code D22 using the server public key K12 obtained from the two-dimensional code D22 of the ticket 81 (S26).

[0028] The verifier U2 who checks the entrant at the event venue confirms the contents described in the electronic document D10 and guides the user U1 to the destination within the venue. The signature verification device 40 requests the electronic document issuing server 10 to verify the authenticity of the server public key K12 extracted from the two-dimensional code D22 of the ticket 81 at a predetermined timing (S27). Multiple methods can be considered as a method for determining whether the server public key K12 is genuine. Although details will be described later, in this embodiment, for example, the server public key K12 is verified by three methods. The first method is a method of separating the personal authentication and the verification of the server public key and verifying the server public key after the personal authentication. The second method is a method of accumulating the verification requests in a queue and requesting the electronic document issuing server 10 to verify the server public key at a timing different from the personal authentication. The third method is a method of downloading the server public key used for verification from the electronic document issuing server 10 to the signature verification device 40 in advance and verifying the server public key within the signature verification device 40. Any of these methods can reduce the load on the electronic document issuing server 10 regarding the verification of the electronic signature.

Example

[0029] The first embodiment will be described with reference to FIGS. 2 to 8. In this embodiment, the server public key is verified by the first method described above. The signature verification device 40A of the electronic signature utilization system 1A according to this embodiment executes the personal authentication based on the electronic signature D21 and the verification of the server public key K12 at different timings.

[0030] As shown in the overall configuration diagram of FIG. 2, the signature verification device 40A acquires the electronic signature D21 and the server public key K12 by decoding the two-dimensional code D22 of the ticket 81 (S21). On the other hand, the signature verification device 40 acquires the biometric information D20 from the user U1 (S22), and generates the personal secret key K21 and the personal public key K22 (S23, S24).

[0031] The signature verification device 40 decrypts the electronic signature D21 using the personal public key K22 obtained from the biometric information D20 of the user U1, and acquires the verification information D11. Thereby, the signature verification device 40 determines that the user U1 who wishes to verify the electronic signature D21 and the user U1 who created the electronic signature D21 using the signature device 20 are the same person.

[0032] Next, after completing the authentication of the user, the signature verification device 40 requests the electronic document issuance server 10 to verify the server public key K12 extracted from the two-dimensional code D22 of the ticket 81 (S27A). When the verification of the server public key K12 is completed, the signature verification device 40 determines that the electronic document D10 is a genuine document.

[0033] FIG. 3 shows a hardware configuration example of the electronic signature utilization system 1A. In the electronic signature utilization system 1A, an electronic document issuance server 10, a signature device 20, a printer 30, and a signature verification device 40 are connected via a communication path CN. The communication path CN may be a dedicated line or a communication network of a public line, or may be an internal bus of a computer.

[0034] The electronic document issuance server 10 is a computer including an arithmetic unit 110, a storage unit 120, and a communication unit 130. The control unit 100 is configured to include the arithmetic unit 110 and the storage unit 120. Details of the arithmetic unit 110 and the storage unit 120 will be described later.

[0035] The signature device 20 is also a computer including an arithmetic unit 210, a memory unit 220, and a communication unit 230. The control unit 200 is configured to include the arithmetic unit 210 and the memory unit 220. A biometric information scanner 52 is connected to the control unit 200 of the signature device 20. The printer 30 attached to the signature device 20 includes a control unit 300, a communication unit 330, and a printing mechanism unit (not shown). The printer 30 may be directly connected to the signature device 20.

[0036] The signature verification device 40 is also a computer including an arithmetic unit 410, a memory unit 420, and a communication unit 430. The control unit 400 is configured to include the arithmetic unit 410 and the memory unit 420. A biometric information scanner 54 and a two-dimensional code scanner 60 are connected to the control unit 200.

[0037] FIG. 4 is a modified example of the hardware configuration of the electronic signature utilization system 1A. In this modified example, instead of the printer 30, a portable information terminal 30A is used as a display output device for the two-dimensional code ticket 81. The portable information terminal 30A includes a control unit 300, a communication unit 330, and a display unit 350. The portable information terminal 30A is configured, for example, as a tablet-type terminal, a laptop-type terminal, a smartphone, or the like. The two-dimensional code ticket 81 is converted by the signature device 20 into electronic data (image data) that can be displayed on a digital device such as the portable information terminal 30A.

[0038] FIG. 5 is a functional configuration diagram of the electronic document issuing server 10. By reading and executing a predetermined computer program, the arithmetic unit 110 of the electronic document issuing server 10 realizes functions such as, for example, an electronic document issuing reception unit 111, an electronic document generation unit 112, a key pair generation unit 113, a verification information generation unit 114, a salt generation unit 115, an electronic document issuing unit 116, a personal public key registration reception unit 117, and a server public key verification request reception unit 118. Details of each function 111 to 118 will be described later.

[0039] The memory unit 120 stores, for example, an electronic document D10, a server private key K11, a server public key K12, electronic document verification information (hereinafter referred to as verification information) D11, a user ID D12, a group ID D13, a salt D14, and a personal public key K22. The user ID D12, the group ID D13, and the salt D14 are used in other embodiments described later.

[0040] The electronic document issuance reception unit 111 receives an electronic document issuance request from the electronic document issuance request unit 212 of the signature device 20 described later. The electronic document generation unit 112 generates an arbitrary electronic document D10 and stores it in the memory unit 120. It may also be configured to give the signature device 20 the function of creating the electronic document D10, and transmit the electronic document D10 created by the signature device 20 to the electronic document issuance server 10 and store it in the memory unit 120.

[0041] The key pair generation unit 113 generates a server private key K11 and a server public key K12 and stores them in the memory unit 120.

[0042] The verification information generation unit 114 reads the electronic document D10 and the server private key K11 from the memory unit 120, generates the verification information D11 by encrypting the electronic document D10 with the server private key K11, and stores the generated verification information D11 in the memory unit 120.

[0043] The salt generation unit 115 used in the embodiments described later generates a group ID D13 and a user ID D12, and generates an arbitrary random number array from a known algorithm. The salt generation unit 115 generates a salt D14 by concatenating the generated random number array, the group ID D13, and the user ID into a set. The salt generation unit 115 stores the generated salt D14, the group ID D13, and the user ID D12 in the memory unit 120. The salt generation unit 115 may generate the salt D14 using, for example, the MAC address of the communication unit 130 instead of the group ID D13 and the user ID.

[0044] The electronic document issuing unit 116 transmits the verification information D11 and the electronic document D10 to the electronic document issuing request unit 212 of the signature device 20. In the embodiments described later, the electronic document issuing unit 116 also transmits the salt D14 to the signature device 20.

[0045] The personal public key registration reception unit 117 receives the registration of the personal public key K22. The personal public key registration reception unit 117 receives a processing request from the public key registration request unit 218 of the signature device 20, and stores the received personal public key K22 in the storage unit 120.

[0046] The server public key verification request reception unit 118 receives a request for verifying the server public key K12. The server public key verification request reception unit 118 receives a processing request from the server public key verification request unit 417 of the signature verification device 40, and determines whether the received server public key K12 matches the server public key K12 read from the storage unit 120. The server public key verification request reception unit 118 transmits the verification result of the server public key to the server public key verification request unit 417 of the signature verification device 40.

[0047] The verification of the server public key may be performed by the electronic document issuing server 10 or by the signature verification device 40. In the latter case, the server public key verification request reception unit 118 may transmit the server private key K11 to the server public key verification request unit 417 of the signature verification device 40, and the server public key verification request unit 417 described later may confirm the match of the server private key K11.

[0048] The storage medium MM shown in FIG. 5 is, for example, a flash memory or a hard disk, and transmits and receives a computer program or data to and from the storage unit 120. It is also possible to transfer and install a computer program or the like stored in the storage medium MM to the storage unit, or to transfer and store a computer program or the like stored in the storage unit to the storage medium MM. The same applies to the storage media MM shown in FIGS. 6 and 7.

[0049] FIG. 6 is a functional configuration diagram of the signature device 20. By reading and executing a predetermined computer program, the arithmetic unit 210 of the signature device 20 realizes various functions such as, for example, a biological information acquisition unit 211, an electronic document issuance request unit 212, a key pair generation unit 213, an electronic signature generation unit 214, a signature encoding unit 215, a two-dimensional code synthesis unit 216, a printing rest unit 217, a public key registration request unit 218, an electronic document reissuance verification unit 219, and a data deletion unit 220. Details of each function 211 to 220 will be described later.

[0050] The storage unit 220 stores, for example, biological information D20, electronic document D10, verification information D11, salt D14, personal private key K21, personal public key K22, electronic signature D21, two-dimensional code D22, electronic document with two-dimensional code (here, a ticket) 81, and server public key K12.

[0051] The shock-resistant storage unit 240 is a storage unit that is difficult to read, falsify, and analyze data from the outside. The shock-resistant storage unit 240 stores a seed D23 used in the following embodiments.

[0052] The biological information acquisition unit 211 receives the biological information D20 read by the biological information scanner 52 from the biological information scanner 52 and stores it in the storage unit 220.

[0053] The electronic document issuance request unit 212 requests the electronic document issuance server 10 to issue the electronic document D10. The electronic document issuance request unit 212 receives the electronic document D10, verification information D11, server public key K12, and salt D14 from the electronic document issuance server 10. After verifying whether the server public key K12, the electronic document D10, and the verification information D11 are paired, the electronic document issuance request unit 212 stores them in the storage unit 220.

[0054] The key pair generation unit 213 generates a pair of asymmetric keys, i.e., a personal public key K22 and a personal secret key K21, from the seed D23, the biometric information D20, and the salt D14, and stores them in the storage unit 220. The electronic signature generation unit 214 generates an electronic signature D21 from the verification information D11 and the personal secret key K21, and stores it in the storage unit 220. The processing of the key pair generation unit 213 and the electronic signature generation unit 214 can use the method described in Patent Document 3.

[0055] The signature encoding unit 215 generates a two-dimensional code D22 from the server public key K12, the electronic document D10, the verification information D11, and the electronic signature D21, and stores it in the storage unit 220.

[0056] The two-dimensional code synthesis unit 216 generates an electronic document with a two-dimensional code 81 in which the two-dimensional code D22 is printed at a plurality of locations on the electronic document D10, and stores it in the storage unit 220.

[0057] The printing request unit 217 transmits the electronic document with a two-dimensional code 81 to the printer 30 and requests printing.

[0058] The public key registration request unit 218 transmits the personal public key K22 to the electronic document issuing server 101 and requests registration.

[0059] The electronic document reissue verification unit 219 acquires the personal public key K22 registered in the electronic document issuing server 10 from the electronic document issuing server 10, and determines whether the acquired personal public key K22 matches the personal public key K22 generated by the key pair generation unit 213.

[0060] The data deletion unit 220 deletes each piece of information stored in the storage unit 220, i.e., the biometric information D20, the electronic document D10, the verification information D11, the salt D14, the personal public key K22, the personal secret key K21, the electronic signature D21, the two-dimensional code D22, and the electronic document with a two-dimensional code 81, at a predetermined timing.

[0061] FIG. 7 is a functional configuration diagram of the signature verification device 40. By reading and executing a predetermined computer program, the arithmetic unit 410 of the signature verification device 40 realizes functions such as a biological information acquisition unit 411, a two-dimensional code reading unit 412, a two-dimensional code decoding unit 413, a key pair generation unit 414, an electronic signature verification unit 415, an electronic document verification unit 416, a server public key verification request unit 417, and a data deletion unit 418. Details of each function 411 to 418 will be described later.

[0062] The storage unit 420 stores, for example, biological information D20, two-dimensional code D22, server public key K12, salt D14, electronic signature D21, verification information D11, electronic document D10, and personal public key K22. The shock-resistant storage unit 440 stores a seed D23.

[0063] The biological information acquisition unit 411 receives biological information D20 from the biological information scanner 54 and stores it in the storage unit 420. The two-dimensional code reading unit 412 stores the two-dimensional code D22 received from the two-dimensional code scanner 60 in the storage unit 420.

[0064] The two-dimensional code decoding unit 413 generates a server public key K12, a salt D14, an electronic signature D21, verification information D11, and an electronic document D10 from the two-dimensional code D22 and stores them in the storage unit 420.

[0065] The key pair generation unit 414 generates a personal secret key K21 and a personal public key K22 from the seed D23, biological information D20, and salt D14, and stores the personal public key K22 in the storage unit 420. The electronic signature verification unit 415 verifies the electronic signature by decrypting the electronic signature D21 with the personal public key K22 to obtain verification information D11. In the key pair generation unit 414 and the electronic signature verification unit 415, the method described in Patent Document 3 can be used.

[0066] The electronic document verification unit 416 generates an electronic document D10 by decrypting the verification information D11 with the server public key K12 and verifies the electronic document.

[0067] The server public key verification request unit 417 requests verification (genuine or fake determination) of the server public key K12 by transmitting the server public key K12 generated by the key pair generation unit 414 to the electronic document issuance server 10.

[0068] The data deletion unit 418 deletes the biometric information D20, two-dimensional code D22, server public key K12, salt D14, electronic signature D21, verification information D11, electronic document D10, and personal public key 2438 in the storage unit 420.

[0069] Figure 8 is a flowchart showing an overview of the verification timing of the server public key. The signature verification device 40 authenticates the electronic document in step S100. An example of step S100 is shown in steps S21 to S26 of FIG. 2.

[0070] The signature verification device 40 determines whether the authentication of the electronic document has ended (S101). For example, the verifier U2 notifies the signature verification device 40 by a button operation or voice input that the authentication of the electronic document has ended. Alternatively, if the authentication process of the next electronic document is not started even after a certain waiting time has passed, it may be determined that the authentication of the electronic document has ended once.

[0071] When the authentication of the electronic document ends (S101: YES), the signature verification device 40 selects the server public key K12 that requests verification from the un-verified server public keys K12 accumulated in the authentication process of the electronic document up to that point, for the electronic document issuance server 10 (S103). It is also possible to select all of the un-verified server public keys K12, or a part of them.

[0072] The signature verification device 40 transmits the selected server public key K12 to the electronic document issuance server 10 and requests its verification (S104).

[0073] According to this embodiment configured as described above, a personal private key and a personal public key are generated from biometric information D20 by one-way conversion, and the verification information D11 acquired from the electronic document issuance server 10 is encrypted with the personal private key. Therefore, even if the verification information D11 is stolen by some means, the biometric information D20 cannot be restored from the verification information D11, and the risk of biometric information leakage can be suppressed. The verification information D11 does not include the biometric information D20, and since the personal private key K21 used for encrypting the verification information D11 is a key one-way converted from the biometric information D20, it is difficult for a third party to extract the user's biometric information D20 even if they analyze the verification information D11.

[0074] In this embodiment, the server public key K12 corresponding to the server private key K11 used for creating the verification information D11 is added to the electronic signature D21 to generate a two-dimensional code D22, which is printed on the ticket 81. Therefore, in this embodiment, a device such as an IC card is not required, and personal authentication can be performed with a relatively inexpensive ticket 81, reducing the cost of the electronic signature utilization system 1.

[0075] In this embodiment, since the processing of the electronic document issuance server 10 is not required during personal authentication by the signature verification device 40, the processing load on the electronic document issuance server 10 can be reduced. In this embodiment, personal authentication can be performed only by the signature verification device 40 without using the electronic document issuance server 10. That is, in this embodiment, it is not necessary to manage the personal public key generated by one-way conversion from biometric information in the electronic document issuance server 10 or an authentication server (not shown), and the configuration of the electronic signature utilization system 1A can be simplified.

[0076] In this embodiment, the personal authentication in the signature verification device 40 and the verification of the server public key K12 can be executed at different timings. Therefore, only the personal authentication can be processed quickly first, and then the server public key K12 can be verified later. Thus, for example, the admission process for attendees at an event venue can be performed promptly, improving usability.

[0077] In this embodiment, since the personal authentication is processed with priority and the verification of the server public key K12 can be postponed, for example, even in a place where the communication state between the signature verification device 40 and the electronic document issuing server 10 such as in a mountainous area or on the ocean is not stable, an electronic signature can be used.

Embodiment

[0078] The second embodiment will be described with reference to FIG. 9. In each of the following embodiments including this embodiment, the differences from the first embodiment will be mainly described. In the electronic signature utilization system 1B of this embodiment, a case where the electronic document issuing server 10 and the signature verification device 40B are always connected will be described. In this embodiment and the third embodiment described later, the configuration of printing the ticket 81 with a two-dimensional code is omitted.

[0079] The signature verification device 40B temporarily stores a verification request for requesting the electronic document issuing server 10 to verify the server public key K12 in the transfer queue 401. The verification requests stored in the transfer queue 401 are transmitted to the electronic document issuing server 10 according to the so-called first-in-first-out method (FIFO) (S27B).

[0080] This embodiment configured in this way also has the same operational effects as the first embodiment. Further, in this embodiment, the signature verification device 40 and the electronic document issuing server 10 are always connected, and the signature verification device 40 puts the verification request for the server public key K12 into the transfer queue 401 and then transmits it to the electronic document issuing server 10. Therefore, compared with the first embodiment, the overhead time for connecting the signature verification device 40 to the electronic document issuing server 10 can be shortened. Further, in this embodiment, even when the communication state between the signature verification device 40 and the electronic document issuing server 10 deteriorates temporarily due to a temporary network failure or the like, the verification request for the server public key is stored in the transfer queue 401, so the verification of the electronic signature can be continued.

Embodiment

[0081] The third embodiment will be described with reference to FIG. 10. In the electronic signature utilization system 1C of this embodiment, in order to verify the server public key K12 extracted from the two-dimensional code D22 of the ticket 81, the server public key K12 is downloaded in advance from the electronic document issuing server 10 to the signature verification device 40C. The signature verification device 40 verifies the server public key K12 obtained from the two-dimensional code D22 of the ticket 81 by using the server public key K12 downloaded in advance (S28C).

[0082] This embodiment configured as described above also has the same operational effects as the first embodiment. Furthermore, in this embodiment, since the server public key K12 is downloaded in advance from the electronic document issuing server 10 to the signature verification device 40, the signature verification device 40 can verify the electronic signature without communicating with the electronic document issuing server 10. Therefore, for example, even in a place where it is difficult for the electronic document issuing server 10 and the signature verification device 40 to communicate, such as an underground event venue, the electronic signature can be used.

Embodiment

[0083] The fourth embodiment will be described with reference to FIG. 11. In the electronic signature utilization system 1D of this embodiment, a plurality of two-dimensional codes D22(1) to D22(3) are generated and printed in a dispersed manner in the margin area of the ticket 81.

[0084] FIG. 11 is an explanatory diagram focusing on the electronic document issuing server 10D and the signature device 20D in the electronic signature utilization system 1D.

[0085] The signature device 20D acquires the biometric information D20 of the user U1 from the scanner 52 a plurality of times (for example, 3 times). Codes D20(1) to D20(3) are attached to each biometric information. In this embodiment, two-dimensional codes D22(1) to D22(3) are respectively generated from these three pieces of biometric information D20(1) to D20(3).

[0086] The signature device 20D adds a seed D23 to each piece of biometric information D20(1) to D20(3) (S31) and generates personal private keys K21(1) to K21(3). The seed D23 is information that the signature device 20D and a signature verification device (not shown) have in common and is stored in a shock-resistant memory unit.

[0087] On the other hand, the electronic document issuing server 10D adds the user ID D12 and the group ID D13 to the electronic document D10 (S32) and generates salts D14(1) to D14(3) which are arrays of different predetermined byte counts from their values (S33). The signature device 20D acquires the salts D14(1) to D14(3) from the electronic document issuing server 10D and adds them to the personal private keys K21(1) to K21(3) (S34).

[0088] The group ID D13 is a unique value for each event or organization, for example. By adding the salts D14(1) to D14(3) including the group ID D13 to the personal private keys K21(1) to K21(3), the scope of use or the period of use of the electronic signatures D21(1) to D21(3) based on the biometric information D20(1) to D20(3) can be restricted.

[0089] The signature device 20D generates a plurality of electronic signatures D21(1) to D21(3) by encrypting the verification information D11 using a plurality of personal private keys K21(1) to K21(3) respectively (S17).

[0090] The signature device 20D generates a plurality of two-dimensional codes D22(1) to D22(3) by adding the server public key K12 to each of the plurality of electronic signatures D21(1) to D21(3) and encoding them (S18).

[0091] The plurality of two-dimensional codes D22(1) to D22(3) are printed in a dispersed manner in a plurality of blank areas of the ticket 81. The two-dimensional codes D22(1) to D22(3) may be printed at any three of the four corners on the front side of the ticket 81, or may be printed separately in the blank area on the front side and the blank area on the back side of the ticket 81. Alternatively, the two-dimensional codes D22(1) to D22(3) may be printed in the blank area on the front side and the blank area on the back side of the ticket 81, respectively.

[0092] The signature verification device 40 (not shown) shall consider the authentication as successful if the authentication of the user is successful with any one of the plurality of two-dimensional codes D22(1) to D22(3).

[0093] The present embodiment configured as described above also has the same operational effects as the first embodiment. Furthermore, according to the electronic signature utilization system 1D of the present embodiment, since different two-dimensional codes D22(1) to D22(3) are printed in a dispersed manner in the blank area of the ticket 81, even if the ticket 81 is bent or soiled, the possibility of correctly verifying the signature increases, improving the convenience for the user U1 and the verifier U2 of the electronic signature utilization system 1D.

[0094] In the present embodiment, since the salts D14(1) to D14(3) including the group ID D13 are added to the personal private keys K21(1) to K21(3), the expiration date and the usage range of the electronic signatures D21(1) to D21(3) can be controlled, improving the usability.

[0095] In the present embodiment, since the seeds D23 are added to the biometric information D20(1) to D20(3) and then the personal private keys K21(1) to K21(3) are generated by one-way conversion, the biometric information can be further protected.

[0096] The technique of using the seed D23 and / or the salt D14 described in the present embodiment for generating the personal private key K21 can be used in any of the first to third embodiments.

Embodiment

[0097] The fifth embodiment will be described with reference to FIG. 12. In this embodiment, a case where an electronic document issuing unit 10E, a signature unit 20E, (if possible) a display output unit 30E, and a signature verification unit 40E are integrated into one computer 70 is shown.

[0098] FIG. 12 is an overall configuration diagram of the electronic signature utilization system 1E of this embodiment. A biometric information scanner 50 and a two-dimensional code scanner 60 are connected to the computer 70. The computer 70 includes, for example, an arithmetic unit 710, a storage unit 720, and a user interface (UI in the figure) unit 730.

[0099] By the arithmetic unit 710 reading and executing a predetermined computer program (not shown) stored in the storage unit 720, the electronic document issuing unit 10E, the signature unit 20E, the display output unit 30E, and the signature verification unit 40E are realized. The electronic document issuing unit 10E corresponds to the electronic document issuing server 10. The signature unit 20E corresponds to the signature device 20. The display output unit 30E corresponds to a display output device 30 such as a printer. The signature verification unit 40E corresponds to the signature verification device 40.

[0100] The display output unit 30E may be configured as a peripheral device independent of the computer 70 and connected to the computer 70.

[0101] This embodiment configured in this way also has the same operational effects as the first embodiment. In the electronic signature utilization system 1E of this embodiment, since the electronic document issuing unit 10E, the signature unit 20E, the display output unit 30E, and the signature verification unit 40E are provided in the computer 70, the biometric information D20 used when creating the electronic signature and the biometric information D20 used when verifying the electronic signature can be obtained using the common biometric information scanner 50. As a result, since stable biometric information D20 can be used, the reliability of the electronic signature utilization system 1E can be further improved.

[0102] Note that the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, for a part of the configuration of each embodiment, addition, deletion, or replacement with other configurations is possible.

[0103] In addition, each of the above configurations may be configured such that part or all of them are configured by hardware or are realized by a program being executed by a processor. Also, the control lines and information lines show those considered necessary for explanation, and not necessarily all the control lines and information lines on the product are shown. In fact, it may be considered that almost all the configurations are interconnected.

[0104] The above-described embodiments disclose a computer program for causing a computer to function as an electronic signature device. That is, "a computer program for causing a computer to function as an electronic signature device, wherein the computer acquires biometric information of a user who performs an electronic signature, generates a personal private key and a personal public key by one-way conversion from the acquired biometric information, generates an electronic signature by encrypting verification information generated by an electronic document issuing server and stored in the storage unit using the personal private key, converts the generated electronic signature into a displayable code, and causes the converted code to be displayed on the predetermined medium."

Explanation of Reference Numerals

[0105] 1: Electronic signature utilization system, 10: Electronic document issuance server, 20: Signature device, 30: Printer, 40: Signature verification device, 60: Two-dimensional code scanner, 81: Electronic document with two-dimensional code (ticket), D10: Electronic document, D11: Electronic document verification information, D20: Biometric information, D21: Electronic signature, D22: Two-dimensional code, K11: Server private key, K12: Server public key, K21: Personal private key, K22: Personal public key

Claims

1. An electronic signature device, comprising a control unit and a storage unit used by the control unit, wherein the control unit acquires a plurality of biometric information of the user for whom the electronic signature is to be made, generates a plurality of personal private keys and personal public keys by adding different random numbers generated by an electronic document issuing server to the plurality of acquired biometric information and performing one-way conversion, generates a plurality of electronic signatures by encrypting the verification information generated by the electronic document issuing server and stored in the storage unit for each of the plurality of personal private keys, generates a displayable code from each of the plurality of generated electronic signatures, and distributes and displays the plurality of generated codes on a predetermined medium Electronic signature device.

2. When the plurality of codes displayed on the predetermined medium are read by a signature verification device for verifying the electronic signature, and when the signature verification device determines that any one of the plurality of electronic signatures obtained from the plurality of codes is genuine, the predetermined medium is determined to be genuine The electronic signature device according to claim 1.

3. An electronic signature utilization system, comprising an electronic signature device, an electronic document issuing server, and a signature verification device, wherein the electronic document issuing server issues verification information and supplies it to the electronic signature device, the electronic signature device acquires biometric information of the user for whom the electronic signature is to be made, generates a personal private key and a personal public key by performing one-way conversion from the acquired biometric information, generates an electronic signature by encrypting the verification information acquired from the electronic document issuing server using the personal private key, converts the generated electronic signature into a displayable code, and displays the code on a predetermined medium, the signature verification device generates a personal private key and a personal public key by performing one-way conversion from the biometric information acquired from the user, and decrypts the electronic signature acquired from the code displayed on the predetermined medium using the generated personal public key, furthermore, the electronic document issuing server generates the verification information by encrypting an electronic document with a server private key, and supplies a server public key corresponding to the server private key to the electronic signature device, the electronic signature device generates the code by adding the server public key received from the electronic document issuing server to the electronic signature, and displays the converted code on the predetermined medium, The signature verification device acquires the electronic signature and the server public key from the code displayed on the predetermined medium, and performs the authenticity determination of the electronic signature and the authenticity determination of the server public key acquired from the code at different timings. Furthermore, the electronic document issuing server supplies a plurality of different random numbers to the electronic signature device. The electronic signature device acquires a plurality of biometric information of the user who signs the electronic signature, generates a plurality of personal private keys and personal public keys by adding the different random numbers to the acquired plurality of biometric information and performing one-way conversion, generates a plurality of electronic signatures by encrypting the verification information for each of the plurality of personal private keys, generates a code that can be displayed from each of the generated plurality of electronic signatures, and causes the generated plurality of codes to be displayed on the predetermined medium. When the signature verification device determines that any one of the plurality of electronic signatures acquired from the plurality of codes displayed on the predetermined medium is genuine, the predetermined medium is determined to be genuine. Electronic signature utilization system.

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