JP2006107247A - Time stamping service system, time stamp information verification server apparatus and computer software - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method that certifies that time stamp information was valid even after the valid period of a public key certificate included in the time stamp information has passed or after an encryption algorithm or a key has been compromised. <P>SOLUTION: A system comprises a client 100, a time stamp information issuing apparatus 102, a certification authority 104 and a verification server 110. The server 110 has means for accepting a message requesting the verification of time stamp information from the client 100 and verifying the time stamp information, means for searching saved verification records if the first verification fails, means for verifying data authentication data in a verification record of the time stamp information showing previous verification, and means for sending the second verification result as a verification response message if the second verification passes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a time stamp technology that guarantees the existence time of electronic data and the integrity of data after that, and more particularly to a technology that verifies the validity of time stamp information.

  With the increase of electronic data due to the advancement of an advanced information and communication network society, it has become important to ensure the originality of electronic data that is relatively easily altered compared to paper documents. Under such circumstances, time stamp technology and time stamp service for proving the existence time of electronic data and the presence or absence of falsification of the data are attracting attention. The time stamp service is a service provided by a reliable third party organization called TSA (Time Stamping Authority). The service user transmits a message digest value, which is a characteristic amount unique to the electronic data to be time stamped, to the TSA. The TSA creates a time stamp token in which the message digest value and the time information referred from the reliable time source are linked by the cryptographic technique, and returns it to the user. By verifying the received time stamp token (time stamp information) and the electronic data, the user can check the existence time of the electronic data and whether or not the electronic data has been tampered with (see, for example, Non-Patent Document 3).

  The method of verifying time stamp information depends on the method of creating time stamp information (see, for example, Non-Patent Document 1, Non-Patent Document 4, and Non-Patent Document 5). For example, when the time stamp information is a digital signature, the time stamp information is verified by verifying the digital signature. If the time stamp information is created by the link token method, the TSA that can verify the validity of the link information included in the time stamp information is accessed, and the validity of the time stamp information is verified. There is a need.

  Some time stamp techniques using a digital signature are based on the PKI technique (for example, Non-Patent Document 2) (for example, Patent Document 1, Non-Patent Document 1, and Non-Patent Document 4). . The TSA public key certificate issued by the certificate authority includes a public key used for verifying the digital signature included in the TSA subject name and time stamp information. When verifying the time stamp, first, the validity of the public key certificate of the TSA is confirmed. In this confirmation, verification of the expiration date of the public key certificate, verification of the revocation status of the public key certificate, verification of the digital signature of the certificate authority assigned to the public key certificate, and the like are performed. Only when the validity is confirmed, the digital signature of the time stamp is verified using this key. If it is determined that the public key certificate is not valid, the verification of the time stamp information fails.

As a countermeasure after the expiration date of the public key certificate, there is also a method of re-assigning a new digital signature using a different cryptographic algorithm or key information while the digital signature is valid (for example, non-patent literature) 6). Here, RFC 3161 compliant time stamps called archive time stamps are used as signature documents and verification information (public key certificate information and certificate revocation list information) before the encryption algorithm or key used in the signature document is compromised. The digital signature data called long-term signature format is created. Further, before the encryption algorithm or key used in this archive time stamp is weakened, a further archive time stamp is applied to the signature document, the verification information, and the previous archive time stamp.
JP 2003-524348 A (pages 33-34, FIG. 8) JP 2001-331104 A JP 2001-331105 A C. Adams, 3 others, RFC 3161, InternetX.509 Public Key Infrastructure Time-Stamp Protocol (TSP), [online], August 2001, [searched July 8, 2004], Internet <URL: http : //www.ietf.org/rfc/rfc3161.txt> Carlyle Adams + Steve Lloyd, translated by Yuichi Suzuki, “PKI Public Key Infrastructure Concepts, Standards, Deployment” Pearson Education Publishing, July 15, 2000, p. 41-52 ISO / IEC 18014-1, "Information technology- Security techniques-Time-stamping services-Part 1: Framework", October 1, 2002 ISO / IEC 18014-2, "Information technology- Security techniques-Time-stamping services-Part 2: Mechanisms producing independent tokens", December 15, 2002 ISO / IEC 18014-3, "Information technology- Security techniques-Time-stamping services-Part 3: Mechanisms producing linked tokens", February 9, 2004 D. Pinkas, 2 others, RFC 3126, RFC-3126 Electronic Signature Formats for long term electronic signatures, [online], September 2001, [searched July 8, 2004], Internet <URL: http: / /www.ietf.org/rfc/rfc3126.txt>

  When verifying time stamp information using a digital signature based on the conventional PKI technology, it was necessary to first verify the TSA public key certificate. At this time, if it is determined that the public key certificate is not valid, the verification fails, and the existence time of the electronic data subject to the time stamp and the presence / absence of alteration cannot be verified. For example, after the expiration date of the public key certificate has passed, the certificate authority does not guarantee the association between the TSA subject name and the public key described in the public key certificate, and the revocation status ( (Certificate revocation list information) is not managed or disclosed. Therefore, even if the digital signature was valid at the time of signing, there was a problem that the reliability of the signature would be greatly lost if the expiration date of the public key certificate passed. In addition, the electronic signature based on the long-term signature format has a problem that the data size increases each time the time stamp is applied, and the re-signature operation is relatively troublesome. Therefore, an improved time stamp information verification technique is desired.

  The present invention has been devised in order to solve the above-described problems, and the encryption algorithm or key used for the time stamp information is compromised after the expiration date of the public key certificate included in the time stamp information. A time stamp information verification server device and a time stamp information verification method for proving that time stamp information has been valid in the past are provided.

  The present invention also provides a time stamp information verification server device and a time stamp information verification method that guarantee the authenticity of time stamp information over a long period of time without increasing the data size of the time stamp information.

  In one aspect, the present invention provides one or more client devices, one or more time stamp information issuing devices, one or more certificate authority devices, and one or more time stamp information verification servers connected to each other via a communication network. When a time stamp information verification server device that verifies the validity of time stamp information in a time stamp service system configured from the device receives a message requesting verification of time stamp information from a client device, the time stamp information in the message When the information is verified and the verification is successful, a verification result is created, a verification record is created, and data authentication information for the verification record is created, and the authentication data and the verification record are stored. It is sent to the client device as a message. If the verification fails, the stored verification record is searched, and if the time stamp information has been determined to have been verified before, the corresponding verification record is identified and the data authentication data of the verification record is verified. If the verification is successful, a verification result including the past verification result is created, the verification record is created, and data authentication information for the verification record is created, and the authentication data and the verification record are stored. As a verification response message.

  According to the present invention, even if the time stamp information has expired, if the time stamp information has been validated while being valid, the time stamp information can be obtained by using a verification record with improved reliability. The validity of the time stamp information based on the past verification result can be claimed without increasing the data size of the information.

The best mode for carrying out the present invention will be described.
Hereinafter, embodiments of a time stamp service system and a time stamp information verification server device according to the present invention will be described in detail with reference to the drawings.

  Example 1 will be described. FIG. 1 shows a time stamp service system configuration of the present embodiment. The time stamp service system includes a plurality of client devices 100, one or more time stamp information issuing devices 102, one or more certificate authority devices 104, one or more time stamp information verification server systems 110, and these devices and systems. The communication network 150 is connected.

  The client device 100 is a client device that issues a request to the time stamp information issuing device 102 in order to obtain time stamp information for electronic data such as contracts and applications, or audit log data such as communication logs and system logs. is there. Further, the client device 100 requests the time stamp information verification server system 110 to perform verification in order to confirm the validity of the time stamp information.

  The time stamp information issuing device 102 is a device that receives a request from the client device 100 and issues time stamp information. Each of these time stamp information issuing devices may implement a unique time stamp method. This apparatus also provides a time stamp information verification function depending on the time stamp method used. For example, the time stamp information issuing device 102-B that creates time stamp information of the link token method provides a function of verifying the time stamp information of the created link token method.

  The certificate authority device 104 is a highly reliable service device used when verifying a digital signature using the PKI technology. Specifically, it comprises certificate authority means for issuing a public key certificate, repository means for publishing a public key certificate revocation list, and OCSP responder means for responding to the validity of the public key certificate. The certificate authority device 104 provides a service to the time stamp information verification server system 110 as needed.

  The time stamp information verification server system 110 includes one or more time stamp information verification front server devices 114, one or more certificate verification server devices 116, a network device 112, and a local network 152 to which these devices are connected. The The time stamp information verification server system 110 is connected to the communication network 150 via the network device 112.

  When receiving the time stamp information request message transmitted from the client device, the time stamp information verification front server device 114 delegates the validity check of the public key certificate included in the time stamp information to the certificate verification server device 116. When the certificate verification server device 116 accesses the certificate authority device 104 and confirms the validity of the public key certificate, the certificate verification server device 116 returns the result to the time stamp information verification front server device 114. The time stamp information verification front server device 114 verifies the digital signature included in the time stamp information using the public key included in the public key certificate whose validity is confirmed. The verification procedure will be described later.

  Example 2 will be described with reference to FIG. The present embodiment is different from the first embodiment in that the time stamp information verification server system is implemented by one apparatus. The time stamp information verification server apparatus 210 includes processing means such as a time stamp information verification request accepting unit 212, a time stamp information verification unit 214, and a time stamp information verification record management unit 216. The time stamp information verification server device 210 stores security data 218 and verification record management data 220. Have.

  The time stamp information verification request reception unit 212 receives a time stamp information verification request transmitted from the client device 100. The time stamp information verification unit 214 confirms the validity of the public key certificate included in the time stamp information and verifies the digital signature included in the time stamp. The time stamp information verification record management unit 216 performs data management such as creation of a record of time stamp information verification processing executed by the time stamp information verification unit 214 and storage in the verification record management data 220.

  The security data 218 stores public key certificate data, private key data owned by the time stamp information verification server device 210, and self-signed certificate data of the certificate authority device 104. Further, the security data 218 may store information (for example, a revocation list of a public key certificate) acquired by using the service of the certificate authority device 104.

  The time stamp information verification server device 210 is preferably a computer including a network connection device that allows a large number of simultaneous accesses and has high-speed processing capability. Specifically, it is realized by a workstation having a large computer or a plurality of central processing units.

  Further, since the time stamp information verification server apparatus 210 provides a time stamp information verification service to the client apparatus 100, high reliability is required. Therefore, it is preferable that the platform system that operates the time stamp information verification processing program has security measures. Specifically, it is desirable that the OS be provided with measures to prevent unauthorized access to the file system and cracking acts via the network. Furthermore, it is desirable that important data from the viewpoint of security, such as public key certificate data and private key data, is managed on tamper-resistant hardware.

  It is assumed that the time stamp information issuing device 102 and the certificate authority device 104 also adopt a platform equivalent to the time stamp information verification server device 210.

  The client device 100 is a general-purpose personal computer having a central processing unit, an input device such as a keyboard and a mouse, a storage device such as a hard disk and a RAM, an output device such as a CRT display, a liquid crystal display and a printer, and a network device for communication. Can be realized. Of course, the computer is not limited to a personal computer, and any computer having an input device, an output device, and a communication device for a user may be used.

  The communication network 150 can be realized by a communication network such as a wired network such as a public network, the Internet, or an ISDN network, or a wireless network using a mobile communication base station or a communication artificial satellite.

  In the time stamp service system, when communicating between devices via the communication network 150, measures may be taken to prevent device impersonation, tampering with communication data, wiretapping of communication data, and the like. This can be realized by using SSL (Secure Sockets Layer) communication technology.

  Each function and each processing unit of each of the above devices is realized by executing a program stored in the storage device by each central processing unit. In addition, each program may be stored in advance in each storage device, and if necessary, propagates over a communication network or a communication network that is a removable storage medium or communication medium that can be used by the device. It may be introduced from another device via a carrier wave.

  FIG. 3 is an example of a flowchart showing a procedure in which the time stamp information verification server device 110 verifies the time stamp information. The second embodiment will be described, but the same applies to the first embodiment. First, the time stamp information verification server device 210 receives a time stamp information verification request message from the client device 100 (step 302).

  The time stamp information verification request message includes at least time stamp information data described later. Moreover, the electronic data itself corresponding to this time stamp information may be included.

  Further, the electronic data corresponding to the time stamp information data may be integrally encoded in a known format format. For example, the electronic data corresponding to the time stamp information may be encoded in a data format unique to the application program or an XML (Extensible Markup Language) format. Information regarding these encoding methods can be indicated in a communication protocol between the client apparatus 100 and the time stamp information verification server apparatus 210. For example, information indicating an encoding format can be included in a content header of HTTP (Hyper Text Transfer Protocol).

The time stamp information verification server device 210 executes verification processing based on the received verification request message (step 304). Examples of verification contents are as follows. The validity of the time stamp information is determined by executing these verification processes.
(1) The validity of the public key certificate included in the time stamp information is confirmed using the revocation list of the public key certificate stored in the security data 218 or the service of the certificate authority device 104.
(2) The digital signature of the time stamp information is verified using the public key included in the public key certificate whose validity has been confirmed.
(3) If other signed data is included, verification is performed in the same manner as described above.
(4) When electronic data corresponding to the time stamp information is included in the time stamp information verification request message, a message digest value of the electronic data is obtained using the corresponding hash function, and this value is included in the time stamp information. Confirm that it is the same as the message digest value.

  The verification contents are not limited to these, and verification items for confirming the reliability of the time stamp information may be added. For example, in order to confirm the reliability of the time information included in the time stamp information, it is possible to confirm the consistency between data items included in the time stamp information or to perform confirmation or verification with reference to reliable external data. Good. Further, the encryption algorithm used for the time stamp information and the security of the key may be confirmed. Further, the time stamp information verification server apparatus 210 can use the result of verification performed by another time stamp information verification server apparatus 210 as a verification result.

  In step 306, if the verification in step 304 is successful (time stamp information is valid), a verification result of the time stamp information is created (step 308). Thereafter, a verification record indicating a verification process record is created and data authentication information for the verification record is created (steps 310 and 312). Finally, the verification record and the data authentication information are stored, and the verification result is returned to the client device 100 (steps 314 and 316).

  In step 306, if the verification in step 304 fails (time stamp information is not valid), the stored verification record is searched (step 320). If it is determined in step 322 that the verification has been performed in the past, the corresponding verification record is specified, and thereafter, the data authentication information associated with the verification record is authenticated (second verification) to verify the authenticity of the verification record. Confirm (step 324). When the authenticity of the verification record is confirmed and the authentication is successful, a verification result of time stamp information including a past verification result is created (step 308). At this time, at least the oldest past verification result is included. Thereafter, a verification record indicating a verification process record is created (step 310) and data authentication information for the verification record is created (step 312). Finally, the verification record and data authentication information are stored (step 314), and the verification result is returned to the client device 100 (step 316).

  If it is determined in step 322 that there is no past verification record, a verification result of time stamp information not including the past verification result is created (step 308). Thereafter, a verification record indicating a verification process record is created (step 310) and data authentication information for the verification record is created (step 312). Finally, the verification record and data authentication information are stored (step 314), and the verification result is returned to the client device 100 (step 316).

  FIG. 4 is an example of time stamp information. The time stamp information 400 includes the following data items. A time stamp identifier field 402 for uniquely identifying time stamp information, a message digest value field 404 of electronic data to be time stamped, and a time information field 406 derived by referring to time information trusted at the time of time stamp creation , A TSA name, a TSA public key certificate, a TSA attribute certificate, an electronic data subject to time stamp, and an authentication information field 410. The authentication information field 410 stores a digital signature for data authentication of a data item group existing above the authentication information field. In order to guarantee long-term data authentication, a digital signature method ("hysteresis signature") using history information disclosed in Patent Document 2, Patent Document 3, and the like may be used. Furthermore, for convenience, a hash function may be used for data authentication.

  FIG. 5 is an example of a verification record. The verification record 500 includes a verification record identifier field 502 for uniquely identifying the verification record, a time stamp information field 504 for storing an entity of time stamp information (for example, binary data of time stamp information), and a public key certificate at the time of verification. A public key certificate validity check information field 506 for storing information such as a certificate revocation list and an OCSP response necessary for checking the validity of the certificate, a verification time field 508 indicating the time when the verification process was performed, and a time The verification result information field 510 stores the verification result of the stamp information.

  FIG. 6 is a table example of the verification record management data 220. The verification record management table 600 has the following four columns. The verification record data column 602 stores binary data of the verification record data 500. The data authentication data column 604 stores data authentication data for the verification record. The time stamp unique information 606 stores information for uniquely identifying the time stamp. For example, a time stamp information identifier 402, a DN (Distinguished Name) of the time stamp issuer, a unique serial number of the time stamp, and a message digest value of the time stamp information are stored. Verification record registration date and time / column 608 indicates the date and time when the created verification record was registered as the verification record data 220.

  FIG. 7 is an example of a verification result screen 700 displayed on the display of the client device 100 that has received the verification result information returned by the time stamp information verification server device 210. The verification result screen 700 includes a plurality of display items. The time information field 702 displays time information included in the time stamp information. A value converted into a national time in consideration of UTC (Universal Coordinate Time) or time zone is displayed. The message digest value field 704 displays the message digest value of the electronic data to be time stamp included in the time stamp information. The verification time field 706 indicates the verification processing execution time of the time stamp information verification server device. The verification result field 708 indicates the time stamp information verification result at the above verification time. In this example, since it is determined that the expiration date of the TSA public key certificate has passed, it is claimed that the time stamp verification result is NG (No Good), that is, the time stamp information is not valid. The past verification time field 710 of the verification record verification result indicates the verification time in the past verification of the corresponding time stamp information stored in the verification record. Furthermore, the past verification result field 712 of the verification record verification result represents the verification result at the past verification time. In this way, even if the time stamp information has expired, if it is valid time stamp information, the time stamp information based on the past verification results can be obtained by using the verification record. You can insist on the validity.

  If a plurality of past verification results are included, a tab-like GUI corresponding to each verification result is displayed on the screen. A user who operates the client device 100 can select a tab using an input device such as a mouse, and browse the corresponding past verification time and verification result.

  A third embodiment will be described. FIG. 8 is another embodiment of the time stamp information verification apparatus 210. Compared to the second embodiment (see FIG. 2), the time stamp information verification apparatus 210 has a verification record reevaluation unit 210 and reevaluation job data 222 added thereto. The verification record re-evaluation unit 210 re-evaluates the verification record data based on the job definition stored in the re-evaluation job data 222.

  FIG. 9 shows a time stamp information verification processing procedure of the time stamp information verification apparatus 210 when the verification record re-evaluation unit 210 and the re-evaluation job data 222 are added. The contents of this process are the same as those in the flowchart shown in FIG. 3 except for the following points, and it is possible to take measures by replacing 900 codes with 300 machines.

  In FIG. 9, reference numeral 915 does not correspond to the addition. The time stamp information verification server apparatus 210 stores the verification record in step 914 and creates and registers a re-evaluation job in step 915.

  The re-evaluation job is a job program for verifying the verification contents performed at the time of verification at a later date. For example, because there is a time difference from the public key certificate revocation procedure to the actual revocation processing / revocation list release, the revocation status of the public key certificate included in the time stamp information is the public key certificate acquired at the time of verification. The revocation list is not fully guaranteed. Therefore, in order to determine the revocation status of the public key certificate at the time of verification, it is necessary to refer to a public key certificate revocation list issued at a later date.

  FIG. 10 is a flowchart of an example of a procedure for re-evaluating a verification record. The re-evaluation process of the verification record is always operated as a background process of the time stamp information verification apparatus, or is regularly operated such as once a day.

  In step 1002, a re-evaluation record in which a job to be executed is defined is acquired. Since the re-evaluation record includes job operation date / time information, it is determined based on this information whether the job is to be processed. For example, a job having a job operation date and time earlier than the current time is an operation target. Next, in step 1004, the public key certificate revocation list distribution point (CRL distribution point) included in the public key certificate data that is the data to be re-evaluated is specified, and then the certificate authority device 104 is accessed. The public key certificate revocation list is acquired (step 1006). In step 1008, the validity of the public key certificate to be re-evaluated is confirmed based on the acquired public key certificate revocation list (step 1008), re-evaluation data is created, and the verification record is updated (step 1008). Steps 1010, 1012). Next, data authentication information for the updated verification record is created (step 1014) and stored with the verification record (step 1016). In step 1004 and step 1006, the public key certificate revocation list is acquired based on the public key certificate revocation list distribution point, and the validity of the public key certificate is confirmed in step 1008. However, other methods may be used. . For example, the authority information access described in the public key certificate may be acquired, and the validity of the public key certificate may be confirmed by connecting to the site indicated by the information. It is assumed that a record relating to a re-evaluation job that has been executed once is deleted after re-evaluation.

  FIG. 11 is an example of a reevaluation record stored in the reevaluation job data. The re-evaluation job can be realized as a database table composed of a plurality of records in which re-evaluation jobs are defined. The verification record identifier / column 1102 stores a unique identifier for specifying the verification record. The job operation date / time column 1104 indicates the time at which the reevaluation job should be started. This time is set to a date later than the next update date (nextUpdate) included in the public key certificate revocation list used when the public key certificate to be re-evaluated is verified. If nextUpdate is December 22, 2003, 8:59:59, for example, the value obtained by adding 1 second to it is set to December 22, 2003, 9:00:00. The reevaluation data column 1106 stores public key certificate data to be reevaluated.

  FIG. 12 is an example of updated verification result data. In the verification record data 1200, a re-evaluation time field 1202 for storing a re-evaluation time and a re-evaluation result information field 1204 indicating a re-evaluation result are added as updated information.

  FIG. 13 is an example of a verification result screen displayed on the client device based on the reevaluation of the verification record. The reevaluation time field 1302 of the verification record verification result indicates the time when the reevaluation was performed. The past verification result field 1304 of the verification record verification result represents a verification result based on the result of the reevaluation. In this example, since the re-evaluation result of the public key certificate is valid, the past verification result is displayed as OK (confirmed) as confirmed. In this way, even if it is time-stamp information that has expired, if it is time-stamp information that has been validated while valid, by using a verification record with further improved reliability by reevaluation, The validity of time stamp information based on past verification results can be claimed.

  In the present invention, it goes without saying that the time stamp information transmitted as a verification request from the client device has a constant data size, that is, does not increase with the passage of time.

  As described in the above embodiments, the present invention verifies the validity of time stamp information with one or more client devices, one or more time stamp information issuing devices, one or more certificate authority devices, and 1 In the time stamp service system comprising the above time stamp information verification server devices connected to each other via a communication network, the time stamp information verification server device sends a message requesting verification of the time stamp information from the client device. First verification means for accepting and verifying time stamp information in the message; second search means for searching for a stored verification record when the first verification fails; and time stamp information previously determined to be verified Identify applicable verification records for and verify data verification data for those verification records 2 verification means, means for creating a second verification result including past verification results when the second verification is successful, means for creating a second verification record and creating second data authentication information for the second verification record And a means for storing the created second authentication data and the second verification record, and a means for transmitting the second verification result as a verification response message to the client device.

  The present invention also relates to a time stamp information verification server device connected to a client device, a time stamp information issuing device, and a certificate authority device through a communication network, and verifying the validity of the time stamp information from the client device. A first verification means for receiving a message requesting information verification and verifying time stamp information in the message; a second search means for searching a stored verification record when the first verification fails; Second verification means for identifying the corresponding verification record for the time stamp information determined to be completed and verifying the data authentication data of the verification record, and the second verification result including the past verification result when the second verification is successful Creating a second verification record and creating second data authentication information for the second verification record And a means for storing the created second authentication data and the second verification record, and a means for transmitting the second verification result to the client apparatus as a second verification response message. .

  The present invention is the time stamp information verification server device in which the second verification result including the past verification result includes at least the oldest verification time among the past verification results of the time stamp information.

  Furthermore, the present invention provides a time stamp information verification server device in which the second verification record includes second time stamp information, second public key certificate validity confirmation information, second verification time, or second verification result information. It is.

  The present invention is the time stamp information verification server device in which the second data authentication information for the second verification record is a digital signature, and the digital signature is created by a digital signature method using a signature history. .

  The present invention includes means for receiving a message requesting verification of time stamp information from the client device, verifying the time stamp information in the message, and creating a first verification result when the first verification is successful; Means for creating a first verification record and creating first data authentication information for the first verification result, means for saving the created first authentication data and first verification record, and using the first verification result as a verification response message A time stamp information verification server device having means for transmitting to a client device.

  Furthermore, the present invention is a time stamp information verification server device having means for creating and registering a reevaluation job when the first verification is successful.

  Further, the present invention is the time stamp information verification server device in which the re-evaluation job is to re-evaluate the validity of the public key certificate included in the time stamp information.

  In the present invention, the operation of the re-evaluation job is time stamp information that is after the next update date and time included in the public key certificate revocation list used when the validity of the public key certificate is confirmed. It is a verification server device.

  Further, the present invention relates to computer software stored in a time stamp information verification server device that is connected to a client device, a time stamp information issuing device, and a certificate authority device through a communication network and verifies the validity of the time stamp information. A first verification function for receiving a message requesting verification of time stamp information from the client device and verifying the time stamp information in the message, and searching for a stored verification record when the first verification fails A second search function, a second verification function for identifying a corresponding verification record for time stamp information that has been previously determined to be verified, and verifying the data authentication data of the verification record, and when the second verification is successful, A function for creating a second verification result including past verification results, a second verification record and a second A function of creating second data authentication information for the certificate record, a function of saving the created second authentication data and the second verification record, and a function of transmitting the second verification result to the client device as a second verification response message; Is computer software comprising a program for causing the time stamp information verification server device to realize the above.

1 is a system configuration diagram of Embodiment 1. FIG. The system block diagram of Example 2. FIG. Explanatory drawing of an example of the flowchart which shows the time stamp information verification operation | movement in a time stamp information verification server apparatus. Explanatory drawing of an example of the structure of time stamp information data. Explanatory drawing of an example of the structure of verification recording data. Explanatory drawing of an example of the table of verification record management data. Explanatory drawing of an example of the screen which shows the verification result of time stamp information. FIG. 6 is a system configuration diagram of Embodiment 3. Explanatory drawing of an example of the flowchart which shows another time stamp information verification operation | movement in a time stamp information verification server apparatus. Explanatory drawing of an example of the flowchart which shows the operation | movement which reevaluates verification recording. Explanatory drawing of an example of the table which stores a re-evaluation job. Explanatory drawing of an example of the data structure of the updated verification record. Explanatory drawing of an example of the screen which shows the verification result of the time stamp information based on re-evaluation of a verification record.

Explanation of symbols

  Client device ... 100, time stamp information issuing device ... 102, certificate authority device ... 104, time stamp information verification server system ... 110, network device ... 112, time stamp information verification front server device ... 114, certificate verification server device ... 116 , Network device ... 112, communication network ... 150, local network ... 152, time stamp information verification server device ... 210, time stamp information verification request receiving unit ... 212, time stamp information verification unit ... 214, time stamp information verification record management unit 216, verification record reevaluation unit 217, security data 218, verification record management data 220, reevaluation job data 222

Claims (10)

In a time stamp service system comprising a client device, a time stamp information issuing device, a certificate authority device, and a time stamp information verification server device for verifying the validity of the time stamp information, which are connected to each other via a communication network ,
The time stamp information verification server device receives a message requesting verification of time stamp information from the client device, and stores the first verification means for verifying the time stamp information in the message, and when the first verification fails. A second search unit for searching the verification record, a second verification unit for specifying the verification record corresponding to the time stamp information that has been previously verified, and for verifying the data authentication data of the verification record; Means for generating a second verification result including a past verification result, means for generating a second verification record and generating second data authentication information for the second verification record, and the generated second authentication upon successful verification; Means for storing the data and the second verification record, and means for transmitting the second verification result to the client device as a verification response message. Time stamp service system according to claim Rukoto. In a time stamp information verification server device that is connected to a client device, a time stamp information issuing device, and a certificate authority device through a communication network and verifies the validity of the time stamp information,
A first verification unit that receives a message requesting verification of time stamp information from the client device and verifies the time stamp information in the message; and a second search that searches a stored verification record when the first verification fails Means, a second verification means for identifying a corresponding verification record for time stamp information that has been previously determined to be verified, and verifying the data authentication data of the verification record, and a past verification result when the second verification is successful Means for generating a second verification result including: means for generating a second verification record and generating second data authentication information for the second verification record; and storing the generated second authentication data and the second verification record Means for transmitting a second verification result to the client device as a second verification response message. Verification server device. In the time stamp information verification server device according to claim 2,
The time stamp information verification server device characterized in that the second verification result including the past verification result includes at least the oldest verification time among the past verification results of the time stamp information. In the time stamp information verification server device according to claim 2,
The time stamp information verification server device characterized in that the second verification record includes second time stamp information, second public key certificate validity confirmation information, second verification time, or second verification result information. In the time stamp information verification server device according to claim 2,
The time stamp information verification server apparatus, wherein the second data authentication information for the second verification record is a digital signature, and the digital signature is created by a digital signature method using a signature history. In the time stamp information verification server device according to claim 2,
Means for receiving a message requesting verification of time stamp information from the client device, verifying the time stamp information in the message, and generating a first verification result when the first verification is successful; and generating a first verification record And means for generating first data authentication information for the first verification result, means for storing the generated first authentication data and first verification record, and means for transmitting the first verification result to the client device as a verification response message. And a time stamp information verification server device. In the time stamp information verification server device according to claim 6,
A time stamp information verification server device comprising means for creating and registering a reevaluation job when the first verification is successful. In the time stamp information verification server device according to claim 7,
The time stamp information verification server device characterized in that the re-evaluation job is to re-evaluate the validity of the public key certificate included in the time stamp information. In the time stamp information verification server device according to claim 8,
Time stamp information verification characterized in that the operation of the re-evaluation job is after the next update date / time included in the public key certificate revocation list used when the validity of the public key certificate is confirmed Server device. Computer software stored in a time stamp information verification server device that is connected to a client device, a time stamp information issuing device, and a certificate authority device through a communication network, and verifies the validity of the time stamp information,
A first verification function for receiving a message requesting verification of time stamp information from the client device and verifying the time stamp information in the message; and a second search for searching a stored verification record when the first verification fails A function, a second verification function that identifies a corresponding verification record for time stamp information that has been previously verified, and verifies the data authentication data of the verification record, and a past verification result when the second verification is successful A function of creating a second verification result including the function of creating a second verification record and creating second data authentication information for the second verification record, and storing the created second authentication data and the second verification record The time stamp information verification server apparatus has a function and a function of transmitting a second verification result to the client apparatus as a second verification response message. Computer software consisting of a program that revealed.

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