KR100697132B1 - Time stamp service system, time stamp information verification server apparatus, and recording medium - Google Patents

Abstract

It is an object of the present invention to provide a method for proving that time stamp information is valid in the past, even after the expiration date of the public key certificate included in the time stamp information or after the encryption algorithm or key is compromised. To this end, in the system consisting of the client 100, the time stamp information issuing device 102, the authentication station 104, and the verification server 110, the server 110 receives the time stamp information from the client 100. Means for verifying the time stamp information by receiving a message requesting verification of the message, means for retrieving a preserved verification record upon failure of the first verification, and verification record of the time stamp information previously determined to have been verified. Means for verifying data authentication data, and means for transmitting, when the second verification succeeds, the second verification result as a verification response message.

Client device, time stamp information issuing device, certificate authority device, network device, security data

Description

Time stamp service system, time stamp information verification server apparatus, and recording medium {TIME STAMP SERVICE SYSTEM, TIME STAMP INFORMATION VERIFICATION SERVER APPARATUS, AND RECORDING MEDIUM}

1 is a system configuration diagram of the first embodiment.

2 is a system configuration diagram of the second embodiment.

3 is an explanatory diagram of an example of a flowchart illustrating a time stamp information verification operation in the time stamp information verification server apparatus;

4 is an explanatory diagram of an example of a structure of time stamp information data;

5 is an explanatory diagram of an example of a structure of verification record data.

6 is an explanatory diagram of an example of a table of verification record management data;

7 is an explanatory diagram of an example of a screen illustrating a verification result of time stamp information;

8 is a system configuration diagram of the third embodiment.

9 is an explanatory diagram of an example of a flowchart illustrating another time stamp information verification operation in the time stamp information verification server apparatus;

10 is an explanatory diagram of an example of a flowchart illustrating an operation of reevaluating a verification record.

11 is an explanatory diagram of an example of a table that stores a reevaluation job;

12 is an explanatory diagram of an example of a data structure of an updated verification record.

13 is an explanatory diagram of an example of a screen showing a verification result of time stamp information based on re-evaluation of verification records;

<Explanation of symbols for main parts of drawing>

100: client device

102: time stamp information issuing device

104: certificate authority device

110: time stamp information verification server system

112: network device

114: Time stamp information verification front server device

116: certificate verification server device

112: network device

150: communication network

152: local network

210: time stamp information verification server device

212: time stamp information verification request receiving unit

214: time stamp information verification unit

216: time stamp information verification record management unit

217: verification record reevaluation unit

218: security data

220: verification record management data

222: Revaluation Zov Data

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a time stamp technique for ensuring the existence time of electronic data and the integrity of subsequent data, and more particularly to a technique for verifying validity of time stamp information.

With the increase of the electronic data in accordance with the development of the advanced information and communication network society, it is important how to secure the originality of the electronic data which is easy to be altered (forged) relatively easily compared to the paper document. Under these circumstances, attention has been paid to a time stamping technique and a time stamping service which prove the existence time of electronic data and the presence or absence of alteration (falsification) of the data. The time stamp service is a service provided by a trusted third party called TSA (Time Stamping Authority). The service user sends to the TSA a message digest value which is a unique feature amount of the electronic data to be time stamped. The TSA creates a time stamp token in which the message digest value and the time information referenced from the trusted time source are linked by cryptographic technology, and returns to the user. By verifying the received time stamp token (time stamp information) and the electronic data, the user can confirm the existence time and alteration (falsification) of the electronic data (see Non-Patent Document 3, for example).

The verification method of time stamp information depends on the creation method of time stamp information (for example, refer nonpatent literature 1, nonpatent literature 4, and nonpatent literature 5). For example, if the digital signature is given time stamp information, the digital signature is verified to verify the time stamp information. Moreover, if it is time stamp information created by the link token method, it is necessary to access the TSA which can verify the validity of the link information included in this time stamp information, and to verify the validity of the time stamp information.

Some of the conventional time stamp techniques using digital signatures are based on the PKI technique (for example, Non Patent Literature 2) (for example, Patent Literature 1, Non Patent Literature 1, Non Patent Literature 4). The TSA's public key certificate issued from the certificate authority contains the public key used to verify the digital signature included in the TSA's subject name and time stamp information. When verifying the time stamp, first verify the validity of the TSA's public key certificate. In this verification, verification of the validity period of the public key certificate, verification of the validity 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 this 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, verification of the time stamp information fails.

As a countermeasure after the public key certificate expiration date, there is also a method of re-assigning a new digital signature using a different encryption algorithm or key information while the digital signature is valid (see Non-Patent Document 6, for example). Here, the RFC 3161 compliant time stamp, called the archive time stamp, is applied to the signature document and verification information (public key certificate information and certificate invalidation list information) before the encryption algorithm or key used in the signature document is compromised. Create digital signature data called signature format. In addition, another archive time stamp is applied to the signature document, verification information, and the previous archive time stamp before the encryption algorithm or key used in this archive time stamp is compromised.

[Patent Document 1]

Japanese Patent Publication No. 2003-524348 (pages 33-34, Fig. 8)

[Patent Document 2]

Japanese Patent Application Laid-Open No. 2001-331104

[Patent Document 3]

Japanese Patent Application Laid-Open No. 2001-331105

[Non-Patent Document 1]

C. Adams, et al., RFC 3161, InternetX.509 Public Key Infrastructure Time-Stamp Protocol (TSP), [online], August 2001, [July 8, 2016], Internet <URL: http : //www.ietf.org/rfc/rfc3161.txt>

[Non-Patent Document 2]

Karyl Adams + Steve Lloyd, Yuichi Suzuki, `` The Concept, Standards, and Development of PKI Public Key Infrastructure, '' Pearson Education Publishing, July 15, 2000, pp.41-52

[Non-Patent Document 3]

ISO / IEC 18014-1, Information technology-Security techniques-Time-stamping services-Part 1: Framework, October 1, 2002

[Non-Patent Document 4]

ISO / IEC 18014-2, Information technology-Security techniques-Time-stamping services-Part 2: Mechanisms producing independent tokens, December 15, 2002

[Non-Patent Document 5]

ISO / IEC 18014-3, Information technology-Security techniques-Time-stamping services-Part 3: Mechanisms producing linked tokens, 9 February 2004

[Non-Patent Document 6]

D. Pinkas, et al., RFC 3126, RFC-3126 Electronic Signature Formats for long term electronic signatures, [online], September 2001, [July 8, 16 Search], Internet <URL: http: / /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, verification fails, and the existence time or alteration (falsification) of the electronic data to be time stamped cannot be proved. For example, after the expiration date of a public key certificate, the certification authority does not guarantee the association of the TSA subject name and the public key described in the public key certificate, and the validity state (certificate effective list information) of this public key certificate is not guaranteed. Do not manage or disclose. Therefore, for example, at the time of signing, even if it is a valid digital signature, if the validity period of the public key certificate has passed, the reliability of the signature is greatly lost. In addition, the electronic signature based on the long-term signature format has a problem that the data size increases with each time stamp application and the effort of resigning is relatively large. Accordingly, improved time stamp information verification techniques are expected.

The present invention has been devised to solve the above problems, and even in the past, even after the expiration date of the public key certificate included in the time stamp information or after the encryption algorithm or key used in the time stamp information is in jeopardy. A time stamp information verification server apparatus and time stamp information verification method for verifying that information is valid are provided.

The present invention also provides a time stamp information verification server apparatus and a time stamp information verification method that ensure 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 a time stamp service system comprising at least one client device interconnected to a communication network, at least one time stamp information issuing device, at least one authentication station device, and at least one time stamp information verification server device. The time stamp information verification server apparatus for verifying validity of the time stamp information, upon receipt of a message requesting verification of the time stamp information from the client apparatus, verifies the time stamp information in the message. Creates a verification record, creates data authentication information for the verification record, saves the authentication data and the verification record, and then sends the verification result to the client device as a verification response message. If the verification fails, the stored verification records are searched for, and if the time stamp information is determined that verification has been completed before, the corresponding verification record is specified and the data authentication data of the verification record is verified. If successful, create a verification result including past verification results, create a verification record and create data authentication information for the verification record, preserve this authentication data and verification record, and then verify The result is sent to the client device as a verification response message.

<Example>

An embodiment for carrying out the present invention will be described.

EMBODIMENT OF THE INVENTION Hereinafter, the Example of time stamp service system and time stamp information verification server apparatus of this invention is described in detail using drawing.

The first embodiment will be described. Fig. 1 shows a time stamp service system configuration of this 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 authentication station devices 104, one or more time stamp information verification server systems 110, these devices and systems. It consists of a communication network 150 connected.

The client device 100 issues a request to the time stamp information issuing device 102 in order to obtain time stamp information for electronic data such as a contract or application form or audit log data such as a communication log or system log. to be. In addition, the client apparatus 100 requests the time stamp information verification server system 110 to verify the validity of the time stamp information.

The time stamp information issuing device 102 is a device that accepts a request from the client device 100 and issues time stamp information. These time stamp information issuing apparatuses may implement the original time stamp method, respectively. The apparatus also provides a function for verifying time stamp information depending on the time stamp method used. For example, the time stamp information issuing apparatus 102-B for creating time stamp information of the link token method provides a function of verifying time stamp information of the created link token method.

The authentication station apparatus 104 is a highly reliable service apparatus used when verifying a digital signature using PKI technology. Specifically, it comprises a certificate authority means for issuing a public key certificate, a repository means for publishing a public key certificate effective list, an OCSP responder means for responding to the validity of the public key certificate, and the like. The authentication station apparatus 104 provides the time stamp information verification server system 110 with the occasional service.

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. It consists of. The time stamp information verification server system 110 is connected to the communication network 150 via the network device 112.

When the time stamp information verification front server apparatus 114 receives a time stamp information request message sent from the client apparatus, the front server apparatus 114 delegates to the certificate verification server apparatus 116 the validity verification of the public key certificate included in the time stamp information. When the certificate verification server apparatus 116 accesses the authentication station apparatus 104 and confirms the validity of the public key certificate, the certificate verification server apparatus 116 returns the result to the time stamp information verification front server apparatus 114. Time Stamp Information Verification The front server apparatus 114 verifies the digital signature included in the time stamp information by using the public key included in the public key certificate that has been validated. The verification procedure and the like will be described later.

The second embodiment will be described with reference to FIG. 2. This embodiment differs from the first embodiment in that the time stamp information verification server system is implemented in 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 verifying unit 214, a time stamp information verification record management unit 216, and the like. 218, the verification record management data 220.

The time stamp information verification request accepting unit 212 accepts a time stamp information verification request transmitted from the client apparatus 100. The time stamp information verification unit 214 verifies 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 manages data such as creation of a record of the time stamp information verification process 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, and self-signed certificate data of the authentication station apparatus 104 owned by the time stamp information verification server apparatus 210. The security data 218 may also store information (for example, an effective list of the public key certificate) acquired by using the service of the authentication station apparatus 104.

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

In addition, since the time stamp information verification server apparatus 210 provides the verification service of the time stamp information to the client apparatus 100, high reliability is required. Therefore, it is preferable that security measures are taken in the platform system for running the time stamp information verification processing program. Specifically, it is preferable that the OS is a countermeasure that prevents unauthorized access to the file system or cracking behavior through the network. In addition, from the security point of view such as public key certificate data and private key data, important data is preferably managed on hardware having tamper resistance.

It is assumed that the time stamp information issuing device 102 and the authentication station device 104 also employ the same platform as the time stamp information verification server device 210.

The client device 100 includes a general-purpose personal computer having a central computing device, an input device such as a keyboard or a mouse, a storage device such as a hard disk or RAM, an output device such as a CRT display, a liquid crystal display, a printer, and a network device for communication. It can be realized by using. Of course, the present invention is not limited to the personal computer, but may be any calculator provided with an input device, an output device, and a communication device for the user.

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

Incidentally, in the time stamp service system, measures for preventing the camouflage of the device, alteration (falsification) of the communication data, eavesdropping of the communication data, and the like may be performed at the time of communication between the devices via the communication network 150. This can be realized by using the SSL (Secure Sockets Layer) communication technique.

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

3 is an example of a flowchart showing a procedure for the time stamp information verification server apparatus 110 to verify the time stamp information. Although the second embodiment will be described, the same can be done in the first embodiment. First, the time stamp information verification server apparatus 210 receives a time stamp information verification request message from the client apparatus 100 (step 302).

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

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

The time stamp information verification server apparatus 210 executes verification processing based on the received verification request message (step 304). Examples of verification contents are as follows. By performing these verification processes, the validity of the time stamp information is determined.

(1) The validity of the public key certificate included in the time stamp information is checked using the effective list of the public key certificate stored in the security data 218 or the service of the authentication station apparatus 104.

(2) The digital signature of the time stamp information is verified using the public key included in the valid public key certificate.

(3) If other signature data is included, verification is performed in the same manner as above.

(4) When the 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 the message includes the message in the time stamp information. Check if it is equal to digest value.

In addition, verification content is not limited to these, You may add the verification item for confirming the reliability of time stamp information. For example, in order to confirm the reliability of the time information contained in the time stamp information, you may perform confirmation or verification which referred to the external data which can confirm the reliability or the reliability of the data items contained in the time stamp information. In addition, you may also confirm the encryption algorithm and the security of the key used for the time stamp information. In addition, the time stamp information verification server apparatus 210 can also use what was performed by the other time stamp information verification server apparatus 210 as a verification result.

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

In step 306, if the verification in step 304 fails (the time stamp information has no validity), the accumulated verification record is retrieved (step 320). If it is determined in step 322 that the verification has been completed in the past, a corresponding verification record is specified, and thereafter, authentication (second verification) of data authentication information corresponding to the verification record is performed to confirm the authenticity of the verification record (step 324). If the authenticity of the verification record is confirmed and authentication succeeds, a verification result of time stamp information including past verification results is created (step 308). In this case, at least the oldest past verification result is included. Thereafter, a verification record indicating a record of the verification process 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 that does not include the past verification result is created (step 308). Thereafter, a verification record indicating a record of the verification process 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).

4 is an example of time stamp information. The time stamp information 400 is composed of the following data items. A timestamp identifier field 402 for uniquely identifying the timestamp information, a message digest value field 404 of electronic data subject to a timestamp, a time information field derived with reference to time information trusted at the timestamp creation ( 406, an additional information field 408 and an authentication information field 410 for storing the name of the TSA, the public key certificate of the TSA, the attribute certificate of the TSA, the electronic data to be time stamped, and the like. The authentication information field 410 stores a digital signature for data authentication of a group of data items existing above the authentication information field. In addition, in order to guarantee data authentication over a long period, a digital signature method ("hysteresis signature") using history information disclosed in Patent Document 2, Patent Document 3, or the like may be used. In addition, for simplicity, a hash function may be used for data authentication.

5 is an example of verification records. The verification record 500 includes a verification record identifier field 502 for uniquely identifying the verification record, and a time stamp information field 504 for storing the substance of the time stamp information (for example, binary data of the time stamp information). ), A public key certificate validation information field 506 for storing information such as a certificate validity list or an OCSP response required for validating the public key certificate at the time of verification, and a verification time field indicating the time at which the verification process was performed ( 508, a verification result information field 510 that stores the verification result of the time stamp information.

6 is a table example of the verification record management data 220. The verification record management table 600 has the following four columns. In the verification record data column 602, binary data of the verification record data 500 is stored. The data authentication data column 604 stores data authentication data for verification records. The time stamp unique information 606 stores information for uniquely specifying a time stamp. For example, the time stamp information identifier 402, the Distinguished Name (DN) of the issuer of the time stamp, the unique serial number of the time stamp, and the message digest value of the time stamp information are stored. The 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.

7 is an example of the verification result screen 700 displayed on the display of the client apparatus 100 that has received verification result information returned by the time stamp information verification server apparatus 210. The verification result screen 700 is composed of a plurality of display items. The time information field 702 displays time information included in the time stamp information. The value converted to UTC (Universal Coordinate Time) or national time considering the time zone is displayed. The message digest value field 704 displays a message digest value of electronic data that is a time stamp target included in the time stamp information. The verification time field 706 indicates the verification processing execution time of the time stamp information verification server apparatus. The verification result field 708 indicates the time stamp information verification result at the verification time described above. In this example, since it is determined that the expiration date of the TSA's public key certificate has passed, it is claimed that the time stamp verification result is NG (No Good), that is, the validity of the time stamp information is not valid. The past verification time field 710 of the verification record verification result indicates a verification time in past verification of the corresponding time stamp information stored in the verification record. The past verification result field 712 of the verification record verification result indicates the verification result at the past verification time. In this manner, even if the expiration date is past time stamp information, validity of the time stamp information based on past verification results can be asserted by using the verification record as long as the time stamp information has been verified during validity.

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

The third embodiment will be described. 8 is another embodiment of the time stamp information verification apparatus 210. Compared to the second embodiment (refer to FIG. 2), the time stamp information verification device 210 includes a verification record reevaluation unit 210 and reevaluation job data 222. The verification record reevaluation unit 210 reevaluates the verification record data based on the job definition stored in the reevaluation job data 222.

9 shows the time stamp information verification processing procedure of the time stamp information verification device 210 when the verification record reevaluation unit 210 and the reevaluation job data 222 are added. This processing content is the same as the flowchart shown in FIG. 3 except for the following points, and therefore, correspondence can be made by replacing 300 reference numerals.

In Fig. 9, the additional correspondence is 915. The time stamp information verification server apparatus 210 saves the verification record in step 914, creates and registers a reevaluation job in step 915.

In addition, reevaluation job is a job program for later verification of the verification performed at the time of verification. For example, since there is a time difference from the public key certificate invalidation procedure to the actual effective processing and the effective list disclosure, the effective state of the public key certificate included in the time stamp information is the public key certificate invalidation list obtained at the time of verification. Is not completely guaranteed. Therefore, in order to confirm the effective state of the public key certificate at the time of verification, it is necessary to refer to the public key certificate effective list issued later.

10 is a flowchart of an example of the reevaluation processing procedure of the verification record. The reevaluation process of the verification record is a background process of the time stamp information verification device which is always in operation or is operated regularly, such as once a day.

In step 1002, a reevaluation record is defined in which a job to be executed is defined. Since the reevaluation record contains the job operation date and time information, it is judged whether or not it is a job to execute the process based on this information. For example, a thing having a jove motion date and time past than the current time becomes an operation object. Next, in step 1004, the public key certificate effective list distribution point (CRL distribution point) included in the public key certificate data that is the reevaluation target data is specified, and then the authentication station apparatus 104 is accessed to access the public key certificate. An effective list is obtained (step 1006). In step 1008, the validity of the public key certificate to be reevaluated is confirmed based on the obtained public key certificate effective list (step 1008), the reevaluation data is created, and the verification record is updated (steps 1010 and 1012). Next, data authentication information for the updated verification record is created (step 1014), and stored together with the verification record (step 1016). Further, in steps 1004 and 1006, the public key certificate effective list is obtained based on the public key certificate effective list distribution point, and the validity of the public key certificate is confirmed in step 1008, but other methods may be used. For example, the authority information access described in the public key certificate may be obtained, and the validity of the public key certificate may be verified by connecting to the site indicated by the information. In addition, the record regarding the reevaluation job once performed shall be deleted after reevaluation.

11 is an example of a reevaluation record stored in the reevaluation job data. The reevaluation job can be realized as a database table composed of a plurality of defined records. The verification record identifier column 1102 stores a unique identifier for specifying the verification record. The job operation date and time column 1104 indicates the time at which the reevaluation job starts up. This time is set to be later than the next update date (nextUpdate) included in the public key certificate effective list used when the public key certificate to be reevaluated is verified. If nextUpdate is December 22, 2003 8:59:59, for example, it is set as December 22, 2003, 9:00:00 seconds which is the value which added 1 second to it. The revaluation data column 1106 stores public key certificate data for revaluation.

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

13 is an example of a verification result screen displayed on the client device based on reevaluation of the verification record. The revaluation time field 1302 of the verification record verification result indicates the time at which the revaluation was performed. In addition, the past verification result field 1304 of the verification record verification result indicates the verification result based on the result of the reevaluation. In this example, since the revaluation result of the public key certificate is valid, the past verification result is confirmed as confirmed and is displayed as OK. In this way, even if the validity time is past time stamp information, validity of time stamp information based on past verification results can be obtained by using verification records having improved reliability by re-evaluation if the time stamp information has been validated during validity. I can argue.

Incidentally, in the present invention, of course, the time stamp information transmitted as the verification request as the client device does not always increase with the passage of time.

As described in the above embodiments, the present invention provides at least one time stamp information verification for validating at least one client device, at least one time stamp information issuing device, at least one authentication station device, and time stamp information. In a time stamp service system, wherein the time stamp information verification server device is configured as a server device and is interconnected to a communication network, the time stamp information verification server device receives a message requesting verification of time stamp information from the client device, and time stamp information in the message. Specifying first verification means for verifying the verification, second retrieval means for retrieving the preserved verification records when the first verification fails, and corresponding verification records for the time stamp information previously determined that the verification has been completed; A second verification which verifies the data authentication data of the verification record together Means for creating a second verification result including past verification results upon the success of the second verification, and creating a second verification record and creating second data authentication information for the second verification record. Means, a means for storing the created second authentication data and the second verification record, and means for transmitting a second verification result as a verification response message to the client apparatus.

In addition, the present invention is a time stamp information verification server apparatus, which is connected to a client network, a time stamp information issuing apparatus, and an authentication station apparatus via a communication network, and which verifies validity of time stamp information, from the client apparatus. First verifying means for receiving a message requesting verification of the message and verifying time stamp information in the message, second retrieving means for retrieving a preserved verification record upon failure of the first verification, and prior verification that the verification has been completed. Second verification means for specifying a corresponding verification record with respect to the determined time stamp information and verifying data authentication data of the verification record, and a second verification result including past verification results when the second verification is successful. Means for creating a second verification record and a second data authentication information for the second verification record. It means, and a time stamp information verification server and means for transmitting to the client device the means for preserving the second authentication data and the second verification record with a second created verification result as a second verification response message.

The present invention is a time stamp information verification server apparatus including a second verification result including a past verification result including at least the oldest verification time of the past verification results of the time stamp information.

The present invention is also a time stamp information verification server apparatus including second time stamp information, second public key certificate validation information, second verification time, or second verification result information in the second verification record.

The present invention is also a 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.

The present invention further provides a 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; Means for creating first data authentication information for a first verification result while creating a record, means for preserving the created first authentication data and first verification record, and a first verification result as a verification response message; A time stamp information verification server device comprising means for transmitting to the device.

The present invention is also a time stamp information verification server apparatus including means for creating and registering a reevaluation job when the first verification is successful.

The present invention is also a time stamp information verification server apparatus, wherein the reevaluation job reevaluates the validity of the public key certificate included in the time stamp information.

In the present invention, the trigger of the reevaluation job is a time stamp information verification server apparatus that is after the next update date and time included in the public key certificate validity list used when the validity of the public key certificate is confirmed.

In addition, the present invention is computer software that is connected to a client device, a time stamp information issuing device, and an authentication station device via a communication network, and is stored in a time stamp information verification server device for verifying validity of time stamp information. A first verification function for receiving a message requesting verification of time stamp information from the device and verifying the time stamp information in the message, a second search function for retrieving a stored verification record upon failure of the first verification, and A second verification function for specifying a corresponding verification record with respect to the time stamp information determined to have been verified and verifying 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, and a second verification record, The time stamp information for generating the second data authentication information, storing the created second authentication data and the second verification record, and sending a second verification result as a second verification response message to the client device. It is computer software which consists of a program implemented in a verification server apparatus.

According to the present invention, even if the time stamp information has expired, even if the time stamp information has been validated during validity, by using the verification record with improved reliability, the past verification result can be increased without increasing the data size of the time stamp information. The validity of the underlying time stamp information can be asserted.

Claims (10)

A time stamp information system comprising a client device, a time stamp information issuing device, an authentication station device, and a time stamp information verification server device for verifying validity of time stamp information, wherein the time stamp service system is interconnected by a communication network. The time stamp information verification server apparatus includes first verification means for receiving a message requesting verification of time stamp information from the client apparatus and verifying time stamp information in the message, and when the first verification fails, preserved verification. Second retrieving means for retrieving a record, second retrieving means for specifying a corresponding retrieval record with respect to time stamp information determined to have been previously verified, and verifying data authentication data of the retrieval record; Means for creating a second verification result including past verification results upon a successful verification, means for creating a second verification record and creating second data authentication information for the second verification record; Means for retaining authentication data and a second verification record, and means for sending a second verification result as a verification response message to the client device; Time stamp service system comprising a. A time stamp information verification server device, which is connected to a client device, a time stamp information issuing device, and an authentication station device via a communication network, and which verifies validity of time stamp information, First verification means for receiving a message requesting verification of time stamp information from the client device and verifying the time stamp information in the message, second retrieving means for retrieving a stored verification record upon failure of the first verification; Second verification means for specifying a corresponding verification record with respect to the time stamp information previously determined that the verification is completed, and verifying data authentication data of the verification record, and a past verification result when the second verification is successful. Means for creating a second verification result comprising: means for creating a second verification record and creating second data authentication information for the second verification record, and creating the created second authentication data and the second verification record. Means for preserving, and means for transmitting a second verification result as a second verification response message to the client device. Stamp information verification server device. The method of claim 2, And the second verification result including past verification results comprises at least the oldest verification time of past verification results of the time stamp information. The method of claim 2, And the second verification record includes second time stamp information, second public key certificate validation information, second verification time, or second verification result information. The method of claim 2, And 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 method of 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 writing a first verification result when the first verification is successful, and creating a first verification record. Means for creating first data authentication information for a first verification result, means for storing the created first authentication data and first verification record, and means for sending a first verification result as a verification response message to the client device. Time stamp information verification server device comprising a. The method of claim 6, And means for creating and registering a reevaluation job when the first verification is successful. The method of claim 7, wherein And the reevaluation job reevaluates the validity of the public key certificate included in the time stamp information. The method of claim 8, The trigger of the operation of the reevaluation job is a time stamp information verification server device characterized in that it is after the next update date and time included in the public key certificate validity list used when the validity of the public key certificate is confirmed. A recording medium connected with a client device, a time stamp information issuing device, and an authentication station device via a communication network, and storing a program stored in a time stamp information verification server device for verifying validity of 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 retrieval function for retrieving a stored verification record upon failure of the first verification; A second verification function for specifying a corresponding verification record with respect to the time stamp information determined to have been previously verified and verifying 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 a function, a function of creating a second verification record and creating second data authentication information with respect to the second verification record, and created second authentication data and a second verification record. The time stamp information verification server device having a function of saving and a function of sending a second verification result as a second verification response message to the client device. The recording medium which recorded the program made to realize.

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