JP2003224563A - Signature verification system and method, signature verification program and computer readable recording medium having the program recorded thereon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a signature verification system and method capable of preventing the degradation of the response of a verified result and keeping the secrecy of data contents by sending only the hash value of a signature object data part and a signature data part without sending data with a signature and requesting verification. <P>SOLUTION: In a device for a client, the hash value is calculated for the signature object data part separated by analyzing the contents of the data with the signature (step S103) and a signature verification request application form including the signature data part and the hash value is sent to a signature verification server (step S105). In the signature verification server, the contents of the signature verification request application form from the device for the client are analyzed to acquire the hash value and the signature data part (step S109), the public key of a signing person is acquired on the basis of signing person information included in the signature data part and the validity of the signature data is verified by using the has value, the signature data and the public key of the signing person (step S113). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to safe and reliable EDI (electronic data exchange) on a computer network.
Signature verification system and method for verifying a digital signature required in digital signature communication using public key cryptography in order to realize EC or EC (electronic commerce), and more specifically, a signature from a client via a client device. The present invention relates to a signature verification system and method for verifying an electronic signature by a signature verification server in response to a verification request and returning the verification result to a client device, a signature verification program, and a computer-readable recording medium recording the program.

[0002]

2. Description of the Related Art Generally, a public key certificate of a signer is obtained in order to verify the validity of a given signature with respect to data to which a digital signature is attached (signed data).
After confirming its validity, it is necessary to verify the signature using the public key contained in the public key certificate. In order to confirm the validity of the signer's public key certificate, the CA (Certification Authorit
y: Certificate authority) is required to verify the route verification process to confirm whether it belongs to the CA under the certification of the CA that the verifier trusts, and whether the public key certificate of the CA on the route is revoked. However, if the number of CAs increases and the authentication configuration becomes complicated, the processing load of these also increases.

Therefore, a signature verification server for collectively performing the processing required for the validity verification of a complicated signature is prepared, and a general user (client) sends the signed data to the server to make a verification request. Then, the method that can easily obtain the verification result is, for example, IETF (The Internet Enginee).
Ring Task Force) DVCS (Data Validation)
and Certification Server Protocol: RFC3029).

In this system, as shown in FIG. 6, the client includes the signed data with the signature to be verified from the client device 10 in the application form and sends it to the verification server 20. After obtaining the signed data to be verified from the application form, enter the public key certificate of the signer required to verify the attached signature and the public key certificate of the CA on the route necessary for route verification processing. After obtaining and performing route verification processing, after confirming whether each public key certificate used for route verification processing is invalid, the signature is verified with the public key included in the public key certificate of the signer, and the result Will be included in the report and returned.

[0005]

In the conventional signature verification system described above, when requesting the verification server to verify the validity of the signature attached to the signed data, the signed server itself is included in the application form. To send to
When the data size of the signed data increases, the data transfer time and the like increase, and there is a problem that the response from the verification request to the return of the verification result becomes poor.

Further, conventionally, since signed data is sent to the verification server, there is a problem that the content of the data cannot be kept secret from the verification server.

The present invention has been made in view of the above,
The purpose is to prevent the deterioration of the response of the verification result and to check the data content by sending only the hash value and the signature data part for the signature target data part instead of sending the signed data itself. It is an object of the present invention to provide a signature verification system and method that enables confidentiality, a signature verification program, and a computer-readable recording medium that records the program.

[0008]

In order to achieve the above object, the present invention according to claim 1 verifies an electronic signature by a signature verification server in response to a signature verification request from a client via a client device and verifies the electronic signature. A signature verification system for returning a result to a client device, wherein the client device analyzes the content of signed data and separates a signature target data part and a signature data part including at least signature data generated by a signer. A signed data analysis unit, a signature target data hash unit that calculates a hash value for the separated signature target data unit, and a signature verification request application form including the signature data unit and the hash value are created. A method for sending a signature verification request application that sends the application to the signature verification server, and a report including the signature verification result from the signature verification server. In addition, the signature verification server has a signature verification result acquisition confirmation means for confirming the signature verification result, and the signature verification server accepts the signature verification request application sent from the client device and the signature verification request application acceptance means. A signature verification request application analysis means for analyzing the contents of the request application form and acquiring the hash value and the signature data part for the signature target data part, and the public key of the signer based on the signer information included in the signature data part. Signer public key acquisition means for acquiring, signature verification means for verifying the validity of the signature data using the hash value, the signature data included in the signature data part, and the public key of the signer; It is a gist to have a verification result report creation and transmission means for creating a report including a signature verification result and returning it to the client device.

According to the first aspect of the present invention, in the client device, the content of the signed data is analyzed and the hash value is calculated for the separated data portion to be signed, and the signature data portion and the hash value are calculated. The signature verification request application containing the signature verification request application is sent to the signature verification server, and the signature verification server analyzes the content of the signature verification request application from the client device, acquires the hash value and the signature data section, and acquires the signature data section. The public key of the signer is obtained based on the signer information included in, and the validity of the signature data is verified using the hash value, the signature data, and the public key of the signer, and the report including this signature verification result is issued. Return the data to the client device, and the client device receives the report from the signature verification server and confirms the signature verification result. There is no need to send things, enables signature verification request only the hash value and the signature data,
The transfer data and the data transfer time are reduced, and it is possible to prevent the deterioration of the response depending on the data size of the signed data and to conceal the data content from the signature verification server.

According to the second aspect of the present invention, a signature verification method in which a signature verification server verifies an electronic signature in response to a signature verification request from a client via the client apparatus and returns the verification result to the client apparatus. In the client device, the contents of the signed data are analyzed to separate the signature target data part and the signature data part including at least the signature data generated by the signer into the separated signature target data part. In contrast, a hash value is calculated, a signature verification request application including the signature data part and the hash value is created and sent to the signature verification server, and the signature verification server sends the signature verification request from the client device. The application is accepted, the content of the received signature verification request application is analyzed, and the hash value and signature data for the data part to be signed are analyzed. The public key of the signer based on the signer information included in the signature data part, and obtains the hash value, the signature data included in the signature data part, and the public key of the signer. The signature data is used to verify the legitimacy of the signature data, a report containing this signature verification result is created and returned to the client device, and the client device receives the report containing the signature verification result from the signature verification server. The main point is to confirm the signature verification result.

In the present invention according to claim 2, in the client device, the hash value is calculated for the signature target data part separated by analyzing the content of the signed data, and the signature data part and the hash value are calculated. The signature verification request application containing the signature verification request application is sent to the signature verification server, and the signature verification server analyzes the content of the signature verification request application from the client device, acquires the hash value and the signature data section, and acquires the signature data section. The public key of the signer is obtained based on the signer information included in, and the validity of the signature data is verified using the hash value, the signature data, and the public key of the signer, and the report including this signature verification result is issued. Return the data to the client device, and the client device receives the report from the signature verification server and confirms the signature verification result. There is no need to send things, enables signature verification request only the hash value and the signature data,
The transfer data and the data transfer time are reduced, and it is possible to prevent the deterioration of the response depending on the data size of the signed data and to conceal the data content from the signature verification server.

Further, the present invention according to claim 3 is a signature verification program for verifying an electronic signature in a signature verification server in response to a signature verification request from a client via a client device and returning the verification result to the client device. In the client device, the contents of the signed data are analyzed to separate the signature target data part and the signature data part including at least the signature data generated by the signer into the separated signature target data part. In contrast, a hash value is calculated, a signature verification request application including the signature data part and the hash value is created and sent to the signature verification server,
The report including the signature verification result is received from the signature verification server, the signature verification result is confirmed, the signature verification server accepts the signature verification request application sent from the client device, and the accepted signature verification request The content of the application is analyzed, the hash value and the signature data section for the signature target data section are acquired, the public key of the signer is acquired based on the signer information included in the signature data section, and the hash value and the signature data are acquired. Using the signature data included in the section and the public key of the signer, the validity of the signature data is verified, a report including this signature verification result is created, and returned to the client device. And

According to the third aspect of the present invention, in the client device, the content of the signed data is analyzed and a hash value is calculated for the separated signature target data part, and the signature data part and the hash value are calculated. The signature verification request application containing the signature verification request application is sent to the signature verification server, and the signature verification server analyzes the content of the signature verification request application from the client device, acquires the hash value and the signature data section, and acquires the signature data section. The public key of the signer is obtained based on the signer information included in, and the validity of the signature data is verified using the hash value, the signature data, and the public key of the signer, and the report including this signature verification result is issued. Return the data to the client device, and the client device receives the report from the signature verification server and confirms the signature verification result. There is no need to send things, enables signature verification request only the hash value and the signature data,
The transfer data and the data transfer time are reduced, and it is possible to prevent the deterioration of the response depending on the data size of the signed data and to conceal the data content from the signature verification server.

The present invention according to claim 4 is characterized in that the signature verification program according to claim 3 is recorded on a computer-readable recording medium.

In the present invention according to claim 4, since the signature verification program according to claim 3 is recorded in a computer-readable recording medium, using the recording medium, the distribution property thereof is improved. Can be increased.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a signature verification system according to an embodiment of the present invention. The signature verification system shown in the figure is used by a client who is a verification requester such as a general user, and is connected to a client device 1 that requests a signature verification and the client device 1 via a network 3 such as the Internet. The signature verification server 2 receives a signature verification request from the client via the client device 1, verifies the electronic signature by the request, and returns the verification result to the client device 1.

The client device 1 has a signed data analysis unit 11, a signature target data hash unit 12, a signature verification request application sending unit 13, and a signature verification result acquisition confirmation unit 14, and the signature verification server 2 , Signature verification request application acceptance means 21, signature verification request application analysis means 22, signer public key acquisition means 23, signature verification means 2
4 and the verification result report preparation and transmission means 25.

When the signed data analysis means 11 of the client device 1 reads the signed data, it analyzes the content of the signed data and a signature including the signature target data part and at least the signature data generated by the signer. Separate the data part. The signature target data part is a data part that is a target of the signer to generate an electronic signature (input to the signature function) in the signed data, and the signature data part is the signed data part. The data part that contains at least the signature data generated by the signer, and that is composed of the signer's information for verifying the signature (for example, the identification information of the signer's public key certificate). Is.

The signature target data hash means 12 calculates a hash value for the signature target data part separated by the signed data analysis means 11. The signature verification request application sending means 13 creates a signature verification request application including a signature data part separated by the signed data analysis means 11 and a hash value for the signature target data part calculated by the signature target data hash means 12, This application form is sent to the signature verification server 2 via the network 3. Further, the signature verification result acquisition confirming unit 14 receives the report including the signature verification result returned from the signature verification server 2 and confirms the signature verification result.

The signature verification request application acceptance means 21 of the signature verification server 2 accepts the signature verification request application sent from the client device 1. The signature verification request application form analyzing unit 22 analyzes the content of the signature verification request application form received from the client device 1, and acquires the hash value and the signature data part for the signature target data part. The signer public key acquisition unit 23 acquires the signer's public key based on the signer information included in the signature data section acquired by the signature verification request application analysis unit 22.

Further, the signature verification means 24 includes the hash value acquired by the signature verification request application analysis means 22, the signature data included in the signature data section, and the signer's public key acquisition means 23. The public key is used to verify the validity of the signature data. Verification result report preparation and transmission means 2
5 creates a report including the signature verification result from the signature verification means 24 and returns it to the client device 1.

Next, the operation of the signature verification system configured as described above will be described with reference to the flowchart shown in FIG. 2 and also with reference to FIGS. In addition,
3 to 5 illustrate the flow of processing related to the client device 1 and the signature verification server 2 in the flowchart shown in FIG. 2 by extracting the flow, and the function of each means for executing the extracted processing. Are shown in reference numerals 111 to 252 in association with each step, and the data flow is shown under the extracted and illustrated processing flow. In the data flow, each function has the same reference numeral 111 to 252. Is shown in FIG.

When the client, which is the verification requester, needs to verify the validity of the signature attached to the signed data, the client first executes the file reading function 111 (FIG. 3) of the signed data analysis means 11 of the client device 1. By using this, the signed data to be verified is read, the content of the read signed data is analyzed by the data analysis function 112 (FIG. 3) of the signed data analysis means 11, and the signed data portion and at least the signer The signature data part including the generated signature data is separated and taken out (step S1).
01). The file reading function is a function generally provided in a computer system and can be easily used.

The signed data is, for example, IETF.
CMS (Cryptographic Message Syntax: RFC
2630) etc., the formats such as the components and their arrangement are defined in advance and are generated according to the formats, and the signature target data part and the signature data part can be recognized based on the specified format. is there. Here, when the signed data includes a plurality of signatures, a plurality of signature data parts are acquired for one signature target data part. The file reading function is a function generally provided in a computer system and can be easily used.

Next, the client device 1 has the hash function 121 (FIG. 3) of the signature target data hash means 12.
Using, the hash value for the signature target data separated by the signed data analysis means 11 is calculated (step S
103). An algorithm for calculating the hash value is, for example, SHA-1 of the American National Standards Bureau, and a cryptographic library that implements the algorithm is widely provided. Therefore, the hash function can be easily used.

Using the data editing function 131 (FIG. 3) of the signature verification request application sending means 13, the client device 1 uses the signature data section separated by the signed data analysis means 11 and the signature target data hash means 12. A signature verification request application form including the calculated hash value is created, and the signature verification request application form is verified via the network 3 using the data transmission / reception function 132 (FIG. 3) of the signature verification request application sending means 13. Send to server 2 (step S1
05).

In addition to the above two pieces of information, the information to be included in the signature verification request application form and the information regarding the format of the application form such as the data arrangement method thereof are defined in advance between the client and the server. In addition to the above two pieces of information, examples of information candidates to be included in the application form include the user name of the client requesting the request and the signature of the client for the application form. The data editing function for handling data is a function that can be easily realized in a computer system, and the data transmission / reception function is a function generally provided in a computer system and can be easily used.

When the signature verification server 2 accepts the signature verification request application transmitted from the client device 1 by the data transmission / reception function 211 (FIG. 4) of the signature verification request application acceptance means 21 (step S107), this The content of the received signature verification request application is analyzed by the data analysis function 221 (FIG. 4) of the signature verification request application analysis unit 22, and the hash value and the signature data for the signature target data part included in the signature verification request application are analyzed. Get a copy (step S1)
09). The format of the signature verification request application is
Since the client device 1 and the signature verification server 2 have been defined in advance, it is possible to easily acquire the hash value and the signature data part based on the regulation.

When the signature verification server 2 acquires the hash value and the signature data part for the data part to be signed, the signer public key acquisition means 23 obtains the public key of the signer based on the signer information included in this signature data part. Get (Step S
111).

More specifically, the signature verification server 2 has a public key certificate acquisition function 231 of the signer public key acquisition means 23.
By using (FIG. 4), the signer's public key certificate and the CA on the path necessary for path verification for the signer's public key certificate
Also obtain the public key certificate of. Then, using the obtained public key certificate, the path verification for confirming that the trust path from the public key certificate of the signer to the public key certificate of the CA trusted by the signature verification server 2 is correct is signed. This is performed by the route verification function 232 (FIG. 4) of the public key acquisition unit 23. Further, the signature verification server 2 uses the public key certificate revocation confirmation function 233 (FIG. 4) of the signer public key acquisition means 23,
Confirm that each public key certificate used for route verification has not been revoked. When it is confirmed by these processes that the signer's public key certificate is authentic, the data analysis function 234 (FIG. 4) of the signer public key acquisition means 23 is used to identify the signer's public key certificate. Retrieve the public key from.

Here, as a method of acquiring the public key certificate in the public key certificate acquisition function 231 of the signer public key acquisition means 23, for example, the public key certificate itself necessary for the signature data part received from the client is used. If it is included, it is obtained from it, and if the signer's public key certificate identification information is included, L
There is a method of obtaining a public key certificate from a managed directory by using a directory access function such as DAP. These methods are already widely used techniques and can be easily used.

Further, the route verification processing in the route verification function 232 is performed by the X. As described in 509, the process of verifying the signature of the issuer (CA) given to the lower public key certificate in the trust path by the public key certificate of the upper CA is sequentially published. This is a process that is performed on the key certificate and that it finally reaches the verification by the public key certificate of the highest trusted CA.
Widely used in systems based on (Public Key Infrastructure). Next, in the public key certificate revocation confirmation processing in the public key certificate revocation confirmation function 233, a public key certificate revocation list (CRL: Certif) is used by using a directory access function such as LDAP.
There is a method to obtain an icate Revocation List) and confirm whether or not it is listed on the list. PKI (Public Key I)
Widely used in systems based on (nfrastructure). Regarding the last public key extraction by the data analysis function 234, the format of the public key certificate is X. Since it is regulated by 509, it is possible to easily take out the part of the public key data based on the regulation.

Next, the signature verification server 2 uses the signature verification function 241 (FIG. 4) of the signature verification means 24 to obtain the hash value acquired by the signature verification request application analysis means 22 and the signature data included in the signature data section, And the validity of the signature data is verified using the public key of the signer acquired by the signer public key acquisition means 23 (step S113). That is,
Performs signature verification processing using the hash value, signature data, and public key as input. Note that the signature data is generated by the hash value derived from the signature target data and the signer's private key, and when verifying this, the hash value derived from the signature target data and the signature data, and the signer's private key. The validity of the signature data can be verified by collecting the public keys. The signature verification function can be easily realized by public key cryptography.

When the signature verification server 2 verifies the signature data, the signature verification server 24 uses the data editing function 251 (FIG. 4) of the verification result report preparation and transmission module 25 to report the signature verification result by the signature verification module 24. Is generated, and this report is transmitted to the client device 1 of the client who is the applicant by the data transmission / reception function 252 (FIG. 4) (step S
115). In addition to the signature verification result, the information to be included in the report and the information about the format of the report such as the data arrangement method thereof are defined in advance between the client and the server. The information candidates included in the report include, for example, the operator name of the verification server, the signature of the verification server on the report, the verification date and time, and the like.

The client device 1 transmits the report including the signature verification result transmitted from the signature verification server 2 to the data transmission / reception function 141 of the signature verification result acquisition confirmation means 14.
When received by (FIG. 5), the content of the received report is analyzed by the data analysis function 142 of the signature verification result acquisition confirmation means 14.
(FIG. 5) analyzes and confirms the verification result (step S1)
17). Since the format of the report has been defined in advance between the client device 1 and the signature verification server 2, it is easy to obtain the signature verification result based on the specification.

As described above, when the signature verification server 2 is requested to verify the signature attached to the signed data, the client device 1 calculates the hash value for the data part to be signed, and the signed data itself is obtained. Since the signature verification request can be made only by transmitting the hash value and the signature data for the signature target data part without transmitting it to the signature verification server 2, it is possible to prevent the deterioration of the response and the data depending on the data size of the signed data. The contents can be kept secret from the signature verification server 2.

The processing procedure of the signature verification method of the above embodiment is recorded as a program in a recording medium such as a CD or FD and the recording medium is incorporated into a computer system or the program recorded in the recording medium is recorded. Of course, it is possible to function as a signature verification system that implements the signature verification method by downloading to a computer system via a communication line or installing from a recording medium and operating the computer system with the program. By using such a recording medium, it is possible to improve its distribution.

[0038]

As described above, according to the present invention,
The client device calculates a hash value for the signature target data part, sends a signature verification request application including the signature data part and the hash value to the signature verification server, and the signature verification server sends the hash value, the signature data, and the signature. Since the legitimacy of the signature data is verified using the public key of the person, there is no need to send the signed data itself as in the conventional case, and the signature verification request can be made using only the hash value and the signature data.
The transfer data and the data transfer time are reduced, and it is possible to prevent the deterioration of the response depending on the data size of the signed data and to conceal the data content from the signature verification server.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a signature verification system according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the signature verification system shown in FIG.

FIG. 3 is an explanatory diagram showing functions for processing of a part related to a client device in the flowchart shown in FIG. 2;

FIG. 4 is an explanatory diagram showing functions for processing of a portion related to the signature verification server in the flowchart shown in FIG.

FIG. 5 is an explanatory diagram showing the function of the last process of the part related to the client device in the flowchart shown in FIG. 2;

FIG. 6 is a diagram for explaining a conventional signature verification system.

[Explanation of symbols]

1 Client device 2 Signature verification server 11 Signed data analysis means 12 means for hashing data to be signed 13 Signature verification request application sending method 14 Signature verification result acquisition confirmation means 21 Signature verification request application acceptance means 22 Signature verification request application analysis method 23 Signer public key acquisition means 24 Signature verification means 25 Verification result report preparation and transmission means

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Claims (4)

[Claims] 1. A signature verification system for verifying an electronic signature by a signature verification server in response to a signature verification request from a client via a client device, and returning the verification result to the client device, wherein the client device comprises: A signed data analysis unit that analyzes the content of the signed data and separates the signature target data part and the signature data part including at least the signature data generated by the signer, and a hash value for the separated signature target data part. A signature target data hashing means for calculating a signature verification request application form including a signature data part and the hash value, and a signature verification request application sending means for sending the application to a signature verification server; It has a signature verification result acquisition confirmation means for receiving a report including the signature verification result from the server and confirming the signature verification result. The signature verification server analyzes the content of the signature verification request application, which receives the signature verification request application sent from the client device, and analyzes the content of the signature verification request application, and the hash value and the signature data for the data part to be signed. A signature verification request application analysis means for obtaining a copy part, a signer public key obtaining means for obtaining a public key of a signer based on signer information included in the signature data part, the hash value, included in the signature data part Signature verification means for verifying the legitimacy of the signature data using the signed signature data and the signer's public key, and a verification for creating a report including the signature verification result and returning it to the client device. A signature verification system comprising: a result report preparation and transmission means. 2. A signature verification method in which a signature verification server verifies an electronic signature in response to a signature verification request from a client via the client device and returns the verification result to the client device. Analyzing the content of the signed data, separating the signature target data part and the signature data part including at least the signature data generated by the signer, and calculating a hash value for the separated signature target data part, Create a signature verification request application including the signature data part and the hash value and send it to the signature verification server. The signature verification server accepts the signature verification request application sent from the client device, and accepts this. The content of the signature verification request application is analyzed, and the hash value and the signature data part for the signature target data part are acquired, and the signature The public key of the signer is acquired based on the signer information included in the data section, and the hash value, the signature data included in the signature data section, and the public key of the signer are used to verify the validity of the signature data. Authenticity, create a report containing this signature verification result, and return it to the client device.The client device receives the report containing the signature verification result from the signature verification server and confirms the signature verification result. A signature verification method characterized by: 3. A signature verification program for verifying an electronic signature in a signature verification server in response to a signature verification request from a client via a client device and returning the verification result to the client device. Analyzing the content of the signed data, separating the signature target data part and the signature data part including at least the signature data generated by the signer, and calculating a hash value for the separated signature target data part, Create a signature verification request application containing the signature data part and the hash value, send it to the signature verification server, receive a report containing the signature verification result from the signature verification server, check the signature verification result, and verify the signature verification server. Accepts the signature verification request application sent from the client device, and accepts the received signature verification request application. Content, obtains a hash value and a signature data portion for the signature target data portion, obtains the signer's public key based on the signer information included in the signature data portion, and includes the hash value and the signature data portion. A signature characterized by verifying the validity of the signature data using the signed signature data and the public key of the signer, creating a report including the signature verification result, and returning it to the client device. Verification program. 4. A computer-readable recording medium on which the signature verification program according to claim 3 is recorded.