JP2013046288A - Time stamp application device and time stamp verification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a time stamp application device capable of retaining relation among files to which one time stamp is applied, while enabling detection of falsification.SOLUTION: A scheduler part 42a designates a plurality of arbitrary files to be time stamp application targets. An ERS management file generation part 42c generates an ERS management file including relation among a plurality of arbitrary files. A time stamp and data file acquisition part 42b performs issuance request of one time stamp for the plurality of arbitrary files and the ERS management file to a time stamp station 5, and acquires a time stamp issued by the time stamp station 5 through a communication I/F part 41. An ERS file generation part 42d generates a verification file with which validity of the time stamp can be verified for each of the plurality of arbitrary files and the ERS management file.

Description

  The present invention relates to a time stamp assigning apparatus that issues a request for issuing one time stamp to a plurality of files to a time stamp authority and assigns one time stamp issued by the time stamp authority to a plurality of files. The present invention also relates to a time stamp verification apparatus that verifies the validity of one time stamp assigned to a plurality of files for each file.

  Conventionally, a file in which a plurality of files (for example, data files) are collected is created, one time stamp issuance request is made to the time stamp authority for the collected files, and the time stamp issued by the time stamp authority is It was given to the compiled file.

  However, conventionally, if any one of the files that are subject to time stamping is deleted, it is not possible to create a summary file when verifying the validity of the time stamp. , And authenticity of all the files that constitute the files to be time stamped cannot be guaranteed.

  Therefore, when one time stamp is assigned to multiple files, it is possible to verify the validity of the time stamp even if one or more files are deleted from multiple files that are subject to time stamp assignment. An ERS standard (RFC 4998) that makes it possible to verify the validity of a time stamp for each file has been proposed (for example, Non-Patent Document 1).

FIG. 1 is a conceptual diagram illustrating the relationship between a data file and an ERS file used in a time stamp assigning apparatus and a time stamp verification apparatus corresponding to the conventional ERS standard. When one time stamp t is assigned to a plurality of data files 1, 2, 3, and 4 using a time stamp assigning device (not shown) corresponding to the ERS standard, one hash that is a generation element of the time stamp t The following steps (1) to (3) are performed in order to generate a value (root hash serving as the vertex of the hash tree) h1234.
(1) A hash function h12 generated by combining the hash value h1 of the data file 1 calculated using the hash function H and the hash value h2 of the data file 2 calculated using the hash function H Calculating with H.
(2) A step of calculating a hash value h123 generated by combining the hash value h3 and the hash value h12 of the data file 3 calculated using the hash function H using the hash function H.
(3) A step of calculating a hash value (root hash) h1234 generated by combining the hash value h4 and the hash value h123 of the data file 4 calculated using the hash function H using the hash function H.

  Thereafter, the time stamp assigning apparatus transmits the hash value h1234 to the time stamp authority (TSA) a, and requests the time stamp authority a to generate the time stamp t. When the time stamp authority a receives the hash value h1234, the time stamp authority a generates a time stamp token with an electronic signature using the private key of the time stamp authority a, and returns the time stamp token to the time stamp applier.

  When the time stamp assigning device receives the time stamp token, the time stamp assigning device copies the time stamp t in order to assign one time stamp t to the data files 1, 2, 3, and 4, respectively. Create an ERS file for each file with t and hash tree information for each file. Here, the hash tree information of each data file includes the minimum hash value necessary for deriving the last hash value (root hash h1234) from its own hash value (h1 or h2, h3, h4). Hold in a nested structure. In the conceptual diagram shown in FIG. 1, [] represents a list. Further, in the ERS standard, the hash value of its own is included in the top list, and the hash values of the elements of each list are sorted in ascending order. That is, the hash values in FIG. 1 have a magnitude relationship of h1 <h2, h12 <h3, h123 <h4.

  Therefore, in the conceptual diagram shown in FIG. 1, the time stamp assigning apparatus has the ERS for the data file 1 having the time stamp t and the hash tree information [[h1, h2], [h3], [h4]] of the data file 1. The file, the ERS file for the data file 2 having the time stamp t and the hash tree information [[h1, h2], [h3], [h4]] of the data file 2, and the hash of the time stamp t and the data hash file 3 ERS file for data file 3 having tree information [[h12, h3], [h4]] and ERS for data file 4 having time stamp t and hash tree information [[h123, h4]] of data file 4 Create a file.

  In the ERS standard, the structure of the hash tree is arbitrary. The process of generating the root hash is determined by the structure of the hash tree, and the structure of the list of hash values held in the hash tree information is also determined.

  By creating such an ERS file for each data file, the time stamp verification device corresponding to the ERS standard can verify the validity of the time stamp t (for example, data file 1) and the corresponding ERS. If there is a file (for example, an ERS file for data file 1), the validity of the time stamp t is verified regardless of the existence of another data file (for example, data file 2) with the same time stamp t. Can do. Therefore, according to the system according to the ERS standard, the file can be processed without being affected by the retention period of each file.

RFC4998: Evidence Record Syntax (ERS) (2007.8)

  However, while the ERS standard can verify the validity of a time stamp without being affected by the presence of other data files, the relationship between data files to which a single time stamp is assigned (for example, which data file Have a mechanism for retaining a time stamp or an order relationship between data files). For example, the arrangement of the data files 1, 2, 3, and 4 in the conceptual diagram shown in FIG. 1 is the arrangement of the end nodes in the hash tree structure, and is independent of the order of the data files. Even if the hash tree is constructed by associating the order of the end node and the data files 1, 2, 3, and 4, the hash values are sorted in ascending order in the hash tree information in the resulting ERS file. The relationship between the data files 1, 2, 3, 4 is not maintained.

  Further, since the structure of the hash tree is arbitrary, it is difficult to specify the data files 1, 2, 3, and 4 as the end nodes of the hash tree from the hash value of the hash tree information. Furthermore, although it is possible to identify data files having the same time stamp in the ERS file, the set of data files identified in this way matches the end nodes of the hash tree constructed at the time of time stamp assignment without any excess or deficiency, and data There is no means for confirming whether a file addition or deletion has occurred.

  An object of the present invention is to provide a time stamp assigning apparatus capable of holding a relationship between files to which a single time stamp is assigned so that tampering can be detected.

  Another object of the present invention is to verify the relationship between a plurality of files given a single time stamp and the presence / absence of addition or deletion of files. It is an object to provide a time stamp verification device that does not require time stamp verification according to the ERS standard.

  In order to solve such a problem, the present invention makes a time stamp issuing request to a time stamp authority for a plurality of files, and assigns a time stamp issued by the time stamp authority to a plurality of files. A device, a file designating unit for designating a plurality of arbitrary files to be time stamped, a management file creating unit for creating a management file including a relationship between the plurality of arbitrary files, and a plurality of arbitrary files and management files A time stamp issuance request is issued to the time stamp authority to obtain a time stamp issued by the time stamp authority, and the validity of the time stamp for multiple arbitrary files and management files File creation section for creating each verification file that can be verified Provides a time stamping device, characterized in that it comprises a. As a result, the relationship between a plurality of arbitrary files designated as time stamp assignment targets can be held so that tampering can be detected.

  In such a time stamp assigning device, the time stamp acquisition unit generates a hash tree using hash values of a plurality of arbitrary files and management files, and uses one hash value that is a root hash that is the apex of the hash tree. The time stamp issuance request is made, and the verification file creation unit creates the verification file including the time stamp and one of the plurality of arbitrary files or hash tree information related to the management file. Is preferred.

  In such a time stamp assigning apparatus, the verification file creation unit stores the management file identification information in the storage unit every time the time stamp is acquired, and the management file creation unit sequentially assigns the time stamp to a plurality of files. Preferably, the management file including the identification information stored in the storage unit when the previous time stamp is acquired is created. As a result, it is possible to verify the order relationship between a plurality of arbitrary files and the presence / absence of addition / deletion between sequentially given time stamps.

  Further, the present invention is a time stamp verification device for verifying the validity of a time stamp of a file to which a time stamp is given, and a relationship between a plurality of arbitrary files to which time stamps are given and a plurality of arbitrary files. When receiving a verification request, a storage unit that stores at least a management file to which a time stamp including the arbitrary file and a verification file capable of verifying the validity of the time stamp given to the management file are stored, A time stamp verification unit that verifies the validity of the time stamp from the verification target file and the verification file associated with the file and outputs the verification result, and if the management file is a verification target, Requests the time stamp verification unit to verify the time stamp assigned, and the verification result for the request is A time stamp verification, comprising: a management file verification unit that determines whether an arbitrary file is identified and stored in the storage unit based on a relationship between a plurality of arbitrary files. Providing equipment. Thereby, the relationship between the files of a plurality of arbitrary files can be verified based on the contents of the management file.

  In such a time stamp verification device, the management file verification unit creates linked data in which hash values of a plurality of arbitrary files are linked to a hash value of the management file based on a relationship between the plurality of arbitrary files, and includes the linked data The request is preferably made to the time stamp verification unit. As a result, it is possible to detect the falsification of the arbitrary file as well as verify the validity of the time stamp of the management file and the relationship between the arbitrary files, and the verification of the time stamp for each arbitrary file can be substituted.

  In such a time stamp verification device, the management file further includes hash values of a plurality of arbitrary files, and the management file verification unit, when the verification result for the request is valid, the hash value of the arbitrary file included in the management file And the hash value calculated from the arbitrary file stored in the storage unit, and the comparison result is preferably used as the verification result of the validity of the time stamp assigned to the arbitrary file. As a result, it is possible to detect falsification of an arbitrary file and to substitute verification of the validity of the time stamp for each arbitrary file.

  According to the time stamp assigning apparatus of the present invention, it is possible to hold the relationship between files to which one time stamp is given so that falsification can be detected.

  According to the time stamp verification apparatus of the present invention, it is possible to verify the relationship between a plurality of files given a single time stamp and the presence or absence of addition or deletion of files. There is no need to verify the time stamp according to the conventional ERS standard.

It is a conceptual diagram explaining the relationship between the data file and ERS file which are used with the time stamp provision apparatus and time stamp verification apparatus corresponding to the conventional ERS standard. 1 is a configuration diagram of an electronic signature system in which a time stamp assigning device and a time stamp verification device according to the present invention are used. It is a conceptual diagram explaining the relationship between the data file used by the electronic signature server of FIG. 2, an ERS management file, and an ERS file. It is a figure which shows an example of the format of the data memorize | stored in the data file management system of the electronic signature system of FIG. FIG. 3 is a time stamp assigning process flowchart of the electronic signature server of FIG. 2. 3 is a time stamp verification processing flowchart of the electronic signature server of FIG. 2. It is a figure which shows the other example of the format of the data memorize | stored in the data file management system of the electronic signature system of FIG.

Embodiments of a time stamp assigning apparatus and a time stamp verifying apparatus according to the present invention will be described with reference to the drawings.
The time stamp assigning apparatus according to the present invention creates a management file including a relationship between a plurality of arbitrary files designated as time stamp giving targets, acquires one time stamp for the plurality of arbitrary files and the management file, This is an apparatus that creates verification files that can verify the validity of time stamps for a plurality of arbitrary files and management files.

  The time stamp verification apparatus according to the present invention includes an arbitrary file and a management file to which a time stamp to be verified is attached, a verification file that can verify the validity of the time stamp given to the arbitrary file and the management file, and Are stored in association with each other, and the validity of the time stamp given to the management file including the relationship between multiple arbitrary files is verified from the verification file of the management file. It is a device that performs verification of the relationship between the two.

  FIG. 2 is a configuration diagram of an electronic signature system in which the time stamp assigning apparatus and the time stamp verifying apparatus according to the present invention are used. The electronic signature system shown in FIG. 2 is applied to, for example, an in-house system, and includes a user terminal 1, a business system 2, a data file storage system 3, an electronic signature server 4, a time stamp station 5, and a communication network 6. Have.

  In the system shown in FIG. 2, the user terminal 1 accesses the business system 2 via the communication network 6 to create a data file, and stores the created data file in the data file storage system 3. Further, as will be described later, the electronic signature server 4 gives a time stamp to the data file stored in the data file storage system 3 according to a preset schedule, and verifies the given time stamp.

  The user terminal 1 provides the user with an environment for accessing the business system 2 and executing operations for performing various business processes such as creation of data files. For this purpose, the user terminal 1 is constituted by, for example, a personal computer (PC). The user terminal 1 includes a communication I / F unit 11 that performs communication with the business system 2, the data file storage system 3, and the electronic signature server 4 through the communication network 6, and a control unit 12 that performs various controls of the user terminal 1. , An input unit 13 for inputting various business operations, a display unit 14 for displaying a screen for performing various business processes, and a storage unit 15 for storing various control information used in the control unit 12. And having.

  The communication I / F unit 11 includes a communication interface and a driver that perform communication using a predetermined communication protocol. The control unit 12 includes a CPU, a ROM, a RAM, and the like, and performs overall control of the user terminal 1 according to a program. The input unit 13 includes a mouse, a keyboard, and the like. The display unit 14 is configured by an LCD or the like. The storage unit 15 includes a rewritable nonvolatile memory such as a flash memory and an EEPROM, a magnetic hard disk, a rewritable optical disk, a drive thereof, and the like.

  The business system 2 executes various business processes according to operations on the user terminal 1 and creates a data file based on the processing results. For this purpose, the business system 2 is configured as a server system of the user terminal 1, and a communication I / F unit 21 that communicates with the user terminal 1, the data file storage system 3, and the electronic signature server 4 through the communication network 6, It has the control part 22 which performs various control of the work system 2, and the memory | storage part 23 which memorize | stores the various control information etc. which are used by the control part 22.

  The communication I / F unit 21 includes a communication interface and a driver that perform communication using a predetermined communication protocol. The control unit 22 includes a CPU, a ROM, a RAM, and the like, and performs overall control of the business system 2 according to a program. For this purpose, the control unit 22 includes a business processing unit 22a that executes a business process according to an operation on the user terminal 1, and a data file creation unit 22b that creates a data file based on the processing result of the business processing unit 22a. Have. The storage unit 23 includes a rewritable nonvolatile memory such as a flash memory and an EEPROM, a magnetic hard disk, a rewritable optical disk, a drive thereof, and the like.

  The data file storage system 3 stores a data file created by the business system 2 in response to an operation on the user terminal 1, and an ERS file, an ERS management file, and an ERS terminal file which are explained after being created by the electronic signature server 4. To do. For this purpose, the data file storage system 3 performs various controls of the communication I / F unit 31 that performs communication with the user terminal 1, the business system 2, and the electronic signature server 4 through the communication network 6, and the data file storage system 3. In addition to the above-described data file, ERS file, ERS management file, and ERS end file, the control unit 32 includes a storage unit 33 that stores various control information used by the control unit 32.

  The communication I / F unit 31 includes a communication interface and a driver that perform communication using a predetermined communication protocol. The control unit 32 includes a CPU, a ROM, a RAM, and the like, and performs overall control of the data file storage system 3 according to a program. The storage unit 33 includes a rewritable nonvolatile memory such as a flash memory and an EEPROM, a magnetic hard disk, a rewritable optical disk, a drive thereof, and the like.

  The electronic signature server 4 requests the time stamp authority 5 to issue one time stamp for a plurality of files, and assigns the time stamp issued by the time stamp authority 5 to the plurality of files. Function as. The electronic signature server 4 also functions as a time stamp verification apparatus in the present invention that verifies the validity of one time stamp assigned to a plurality of files for each file. For this purpose, the electronic signature server 4 includes a communication I / F unit 41 that communicates with the user terminal 1, the business system 2, the data file storage system 3, and the time stamp station 5 through the communication network 6, and the electronic signature server 4. In addition to the above-described data file, ERS file, ERS management file, and ERS end file, the storage unit 43 stores various control information used by the control unit 42. In the present embodiment, the electronic signature server 4 corresponds to the ERS standard.

  The communication I / F unit 41 includes a communication interface and a driver that perform communication using a predetermined communication protocol. The control unit 42 includes a CPU, a ROM, a RAM, and the like, and performs overall control of the electronic signature server 4 according to a program. For this purpose, the control unit 42 includes a scheduler unit 42a that operates as a file designation unit of the present invention, a time stamp and file reception unit 42b, an ERS management file creation unit 42c, an ERS file creation unit 42d, and an electronic signature assignment. A unit 42e, an electronic signature verification unit 42f, a file transmission unit 42g, a time stamp verification unit 42h, and an ERS management file verification unit 42i.

  The scheduler unit 42a acquires a plurality of data files stored in the storage unit 33 of the data file storage system 3 in accordance with a preset time set in the schedule, and assigns one time stamp, and a time stamp Gives a trigger to verify the timestamp of the data file to which Specifically, the scheduler unit 42a requests the time stamp and file receiving unit 42b to acquire a time stamp, and requests the time stamp verification unit 42h to verify the time stamp.

  The time stamp and file receiving unit 42b acquires the time stamp through the communication I / F unit 41 by cooperating with the ERS management file creating unit 42c and the ERS file creating unit 42d in response to a request from the scheduler unit 42a. That is, the time stamp and file receiving unit 42 b makes a time stamp issue request to the time stamp station 5 via the communication I / F unit 41, and acquires the time stamp issued by the time stamp station 5. This series of processing corresponds to the processing of the time stamp acquisition unit of the present invention.

  In addition, the time stamp and file receiving unit 42 b obtains a plurality of data files as a plurality of arbitrary files to be given a time stamp specified by the scheduler unit 42 a from the storage unit 33 through the communication I / F unit 41. Therefore, the communication I / F unit 41 and the time stamp and file receiving unit 42b receive a plurality of data files to be time stamped from among a plurality of data files stored in the storage unit 33, and receive one time stamp. The plurality of data files are temporarily stored in the storage unit 43 for assignment.

  The ERS management file creation unit 42c creates an ERS management file including at least an order relationship, which is a kind of relationship between a plurality of data files to be time stamped, in response to a request from the time stamp and file receiving unit 42b. . The order relationship here is information indicating the time-series order in which data files are registered in the storage unit 33 of the data file storage system 3. Specifically, the information indicating the order relationship is information represented in a text format in which file names of data files to be time stamped are listed in the order of registration in the storage unit 33.

  As for the relationship between the plurality of data files, in addition to the order relationship as in the present embodiment, there are various types of information indicating the hierarchical relationship when there are upper and lower hierarchical relationships between the plurality of data files. The group structure in the case of being divided into groups, or a list of all the data file names to which one time stamp is assigned may be used.

  Further, the ERS management file creation unit 42c creates an ERS management file by adding information stored in an ERS termination file described later to information indicating the order relationship. In addition, since the ERS termination file information is added to the ERS management file in order to detect the deletion of the ERS management file, the ERS termination file information is added to the ERS management file if it is not necessary to consider the deletion of the ERS management file. There is no need to add.

  Here, the ERS termination file will be described. The ERS termination file is a file that is updated each time a time stamp is given by the ERS management file creation unit 42c. That is, the ERS management file creation unit 42c records the file name of the created ERS management file and the hash value of the contents of the ERS management file in the ERS terminal file when the time stamp is given. At this time, if the file name or the like is already recorded in the ERS terminal file, the ERS management file creation unit 42c overwrites and updates the ERS terminal file. Thereby, the file name etc. of the latest ERS management file to which the time stamp is given are always recorded in the ERS end file. Further, the ERS management file creation unit 42c assigns an electronic signature to the created ERS termination file with the private key of the electronic signature server 4 by an electronic signature provision unit 42e described later, and stores the ERS termination file to which the electronic signature is attached. Store in the unit 43. In addition, when the ERS management file creation unit 42c acquires the ERS terminal file stored in the storage unit 43 when creating the ERS management file, the electronic signature verification unit 42f described later has verified the electronic signature. The ERS management file is created on the condition.

  The ERS file creation unit 42d creates an ERS file as a verification file capable of verifying the validity of the time stamp, for a plurality of data files and ERS management files to be time stamped.

  The electronic signature attaching unit 42e attaches an electronic signature to the ERS termination file in response to a request from the ERS management file creation unit 42c. The electronic signature verification unit 42f verifies the electronic signature given to the ERS termination file in response to a request from the ERS management file creation unit 42c.

  The file sending unit 42g stores a plurality of data files and ERS management files with one time stamp in order to store a plurality of data files and ERS management files with one time stamp in the storage unit 33, respectively. The ERS file and the ERS terminal file are sent to the data file storage system 3 through the communication I / F unit 41.

  In response to a request from the scheduler unit 42a, the time stamp verification unit 42h performs time stamp verification using the file to be processed and the ERS file of the file. The ERS management file verification unit 42i verifies the ERS management file in response to a request from the time stamp verification unit 42h to verify the relationship between the data files. At that time, the ERS management file verification unit 42i requests the time stamp verification unit 42h to verify the time stamp using the ERS management file and the ERS file of the ERS management file.

  The storage unit 43 includes a rewritable nonvolatile memory such as a flash memory and an EEPROM, a magnetic hard disk, a rewritable optical disk, a drive thereof, and the like.

  In response to the time stamp generation request from the electronic signature server 4, the time stamp authority 5 generates a time stamp token to which the electronic signature is attached using the private key of the time stamp authority 5, and returns the time stamp token to the electronic signature server 4. To do. For this purpose, the time stamp station 5 is used by the communication I / F unit 51 that performs communication with the electronic signature server 4 through the communication network 6, the control unit 52 that performs various controls of the time stamp station 5, and the control unit 52. A storage unit 53 for storing various control information and the like.

  The communication I / F unit 51 includes a communication interface and a driver that perform communication using a predetermined communication protocol. The control unit 52 includes a CPU, a ROM, a RAM, and the like, and performs overall control of the time stamp station 5 according to a program. The storage unit 53 includes a rewritable nonvolatile memory such as a flash memory and an EEPROM, a magnetic hard disk, a rewritable optical disk, a drive thereof, and the like.

  The communication network 6 is connected to the user terminal 1, the business system 2, the data file storage system 3, the electronic signature server 4 and the time stamp station 5. For this reason, the communication network 6 is configured by a communication line that can transmit and receive data between remote places such as a dedicated line, the Internet, a mobile phone line, and a general public line, or between indoor and remote locations.

FIG. 3 is a conceptual diagram illustrating the relationship among a data file, an ERS management file, and an ERS file used in the electronic signature server of FIG. When one time stamp t ′ is given to a plurality of data files 1, 2, 3 using the electronic signature server 4, an ERS management file that records the relationship (for example, order relationship) between the data files 1, 2, 3 is In order to calculate the root hash described with reference to the conceptual diagram shown in FIG. 1 in order to generate one hash value (root hash that becomes the apex of the hash tree) h123R that is created and is a generation element of the time stamp t ′ Following the steps (1) and (2), the following step (3) ′ is performed.
(3) A step of calculating a hash value (root hash) h123R generated by combining the hash value hR and hash value h123 of the ERS management file calculated using the hash function H using the hash function H.

  Thereafter, the electronic signature server 4 transmits the hash value h123R to the time stamp authority (TSA) a corresponding to the time stamp authority 5, and requests the time stamp authority a to generate the time stamp t '. When the time stamp authority a receives the hash value h123R, the time stamp authority a generates a time stamp token to which an electronic signature has been applied using the private key of the time stamp authority a, and sends it back to the electronic signature server 4.

  When the electronic signature server 4 receives the time stamp token, the electronic signature server 4 copies the time stamp t ′ to assign one time stamp t ′ to the data files 1, 2, 3 and the ERS management file, respectively. Then, an ERS file for each file having hash tree information necessary for deriving the root hash h123R from the time stamp t ′ and the hash values h1, h2, h3, hR of each file is created.

Therefore, in the conceptual diagram shown in FIG. 3, the electronic signature server 4 is for the data file 1 having the time stamp t ′ and the hash tree information [[h1, h2], [h3], [hR]] of the data file 1. ERS file, ERS file for data file 2 having time stamp t ′ and hash tree information [[h1, h2], [h3], [hR]] of data file 2, time stamp t ′ and data hash file ERS file for data file 3 having 3 tree information [[h12, h3], [hR]], and ERS management file having time stamp t ′ and hash tree information [[h123, hR]] of the ERS management file An ERS file is created.
Note that the hash values in FIG. 3 have a magnitude relationship of h1 <h2, h12 <h3, h123 <hR.

  By creating such an ERS file for each data file and ERS management file, the time stamp verifying device corresponding to the ERS standard allows time stamps assigned to a plurality of data files 1, 2, 3 and the ERS management file. The validity of t ′ can be verified without distinguishing whether it is a data file or an ERS management file.

  FIG. 4 is a diagram showing an example of a format of data stored in the data file storage system 3 of the electronic signature system of FIG. In FIG. 4, ERS management files of arbitrary files 1, 2, and 3 corresponding to a plurality of data files correspond to the management file A, and time stamp A as one time stamp for arbitrary files 1, 2, 3, and management file A , And verification files 1, 2, 3, A including a time stamp A are created as ERS files for these arbitrary files 1, 2, 3, and management file A, respectively.

  Similarly, in FIG. 4, the ERS management files of arbitrary files 4 and 5 corresponding to a plurality of data files correspond to the management file B, and the time stamp B is set as one time stamp in the arbitrary files 4 and 5 and the management file B. The verification files 4, 5 and B including the time stamp B are created as ERS files for the arbitrary files 4 and 5 and the management file B, respectively.

  Next, with reference to FIG. 5, the time stamp assigning process flow of the electronic signature server 4 of FIG. 2 will be described. Note that the processing flow described below is controlled by a program executed by the control unit 42.

  The electronic signature server 4 of FIG. 2 starts a processing flow for assigning a time stamp when the scheduler unit 42a requests the time stamp and file receiving unit 42b to obtain a time stamp. At this time, the scheduler unit 42a designates a relationship between a plurality of data files (a plurality of arbitrary files) to be processed (time stamp assignment target) and a plurality of data files.

  First, the time stamp and file receiving unit 42b acquires a plurality of data files to be processed from the data file storage system 3, and stores the acquired plurality of data files in the storage unit 43 (step S1).

  Here, when a plurality of data files to be processed cannot be acquired, the time stamp and file receiving unit 42b records the failure of the data file acquisition process as a system error in the storage unit 43, and ends the processing flow. .

  Next, when the time stamp and file receiving unit 42b requests the ERS management file creation unit 42c to create an ERS management file, the ERS management file creation unit 42c acquires the ERS terminal file from the data file storage system 3 and acquires it. The ERS terminal file is stored in the storage unit 43 (step S2).

  Here, when the ERS terminal file cannot be acquired, the ERS management file creation unit 42c records the failure of the ERS terminal file acquisition process in the storage unit 43 as a system error, and ends the processing flow.

  Next, the ERS management file creation unit 42c requests the electronic signature verification unit 42f to verify the signature of the ERS terminal file (step S3). Upon receiving the request, the electronic signature verification unit 42f executes signature verification of the ERS terminal file, and determines whether or not the signature verification of the ERS terminal file has succeeded (step S4). If the signature verification fails, the electronic signature verification unit 42f records the failure of the signature verification process in the storage unit 43 (step S5), and ends the processing flow.

  On the other hand, when the signature verification is successful, the ERS management file creation unit 42c determines whether or not the ERS management file has been recorded in the ERS terminal file, that is, whether or not the time stamp is added for the first time ( Step S6). When the ERS management file has been recorded in the ERS terminal file, the ERS management file creation unit 42c acquires the recorded ERS management file from the file storage system 3, and stores the acquired ERS management file in the storage unit 43 ( Step S7).

  Here, when the ERS management file cannot be acquired, the ERS management file creation unit 42c indicates the possibility of deleting the ERS management file and records the failure of the ERS management file acquisition process in the storage unit 43 as a system error. The processing flow is finished. Next, the ERS management file creation unit 42c stores the acquired ERS management file in the storage unit 43, and whether or not the hash value of the acquired ERS management file matches the hash value recorded in the ERS termination file. (Step S8).

  When the hash value of the acquired ERS management file does not match the hash value recorded in the ERS terminal file, the ERS management file creation unit 42c has detected that the acquired ERS management file has been replaced. Thus, the mismatch of the hash values is recorded in the storage unit 43 (step S9), and the processing flow ends.

  On the other hand, if the hash value of the acquired ERS management file matches the hash value recorded in the ERS termination file, the ERS management file creation unit 42c creates a new one from the processing target data file and the acquired ERS termination file. A ERS management file is created (step S10). On the other hand, if it is determined in step S6 that no ERS management file is recorded in the ERS terminal file, the process proceeds to step S10. At this time, the ERS management file creation unit 42c starts a new ERS management from the data file to be processed. Create a file.

  Next, the ERS management file creation unit 42c creates an ERS termination file in which information of a new ERS management file is recorded in order to update the ERS termination file (step S11). Specifically, the ERS management file creation unit 42c creates an ERS terminal file, and requests the electronic signature provision unit 42e to attach an electronic signature to the created ERS terminal file.

  Next, the electronic signature providing unit 42 e that has received the request provides an electronic signature to the ERS terminal file with the private key of the electronic signature server 4, and stores the terminal file to which the electronic signature has been added in the storage unit 43.

  Next, the ERS management file creation unit 42c creates concatenated hash data in which hash values of a plurality of data files to be processed are concatenated with a hash value of a new ERS management file in the order of data according to the relationship between the data files (step S12). ). Next, the time stamp and file receiving unit 42b creates a hash tree using the hash values and concatenated hash data of a plurality of data files to be processed (step S13).

  Next, the time stamp and file receiving unit 42b requests the time stamp authority 5 to create a time stamp for the root hash of the created hash tree, and acquires the time stamp for the root hash from the time stamp authority 5 (step S14).

  Here, when the time stamp for the root hash is not acquired from the time stamp authority 5, the time stamp and file receiving unit 42b records the failure of the time stamp acquisition process as a system error in the storage unit 43, and the processing flow is as follows. finish.

  Next, the ERS file creation unit 42d creates an ERS file for each data file and ERS management file corresponding to the hash value and linked hash data of each data file from the hash tree and the time stamp, and creates all the ERS files created. Is stored in the storage unit 43 (step S15).

  Next, the file sending unit 42g transmits a new ERS management file, all ERS files, and an ERS terminal file with an electronic signature added to the data file storage system 3 through the communication I / F unit 41 (step S16), and processing End the flow. The data file storage system 3 stores the new ERS management file and all ERS files received from the electronic signature server 4 in the storage unit 33. In addition, the data file storage system 3 overwrites and saves the ERS terminal file received from the electronic signature server 4 over the ERS terminal file stored in the storage unit 33. In the processing flow shown in FIG. 5, for example, when the arbitrary files 1, 2, and 3 shown in FIG. 4 are designated as processing targets, the management file A is created as a new ERS management file, and the arbitrary files 1, 2, and 3 are specified. In addition, verification files 1, 2, 3, and A are created as ERS files of the management file A, respectively.

  According to the processing flow shown in FIG. 5, an ERS management file is created as a management file including a relationship between a plurality of data files, and one time stamp is assigned to the plurality of data files and the ERS management file. Each ERS file is created as a verification file that can verify the validity of the stamp. By creating the ERS file for the management file in this way, the relationship between the data files to which one time stamp is assigned can be held so that tampering can be detected.

  Next, the time stamp verification processing flow of the electronic signature server 4 of FIG. 2 will be described with reference to FIG. Note that the processing flow described below is controlled by a program executed by the control unit 42.

  The electronic signature server 4 in FIG. 2 starts a time stamp verification process flow when the scheduler unit 42a requests time stamp verification from the time stamp verification unit 42h. At this time, the scheduler unit 42a designates a data file (arbitrary file) to be processed (time stamp verification target).

  First, the time stamp and file receiving unit 42b acquires a data file to be processed from the data file storage system 3, and stores the acquired data file in the storage unit 43 (step S101).

  If the data file to be processed cannot be acquired, the time stamp and file receiving unit 42b records the failure of the data file acquisition process as a system error in the storage unit 43, and ends the processing flow. Next, the time stamp verification unit 42h determines whether or not the verification of the order relationship between the data files has been specified (step S102).

  When the order relationship between the data files is not verified, the time stamp and file receiving unit 42b acquires the ERS file as the verification file of the data file to be processed from the data file storage system 3, and the time stamp verifying unit 42h Based on the acquired data file and the corresponding ERS file, the validity verification process of the time stamp of each data file (the time stamp verification process of the existing ERS standard) is executed, and all specified as processing targets A time stamp validity verification process is performed on the data file (step S103), and the process flow ends.

  On the other hand, if it is determined in step S102 that the order relationship between the data files is verified, the time stamp verification unit 42h requests the ERS management file verification unit 42i to verify the ERS management file corresponding to the data file designated as the processing target. Thereafter, the ERS management file verification unit 42i performs the processing independently.

  The ERS management file verification unit 42i acquires from the data file storage system 3 the ERS management file in which the file name of the last file in the processing target data file is recorded and the ERS file of the ERS management file, and manages the ERS management file. The file and the ERS file are stored in the storage unit 43 (step S104). That is, when there is an order among the data files over a plurality of time stamps, the ERS management file to which the latest time stamp is given and the ERS file of the ERS management file are acquired.

  Here, when the ERS management file and the ERS file cannot be acquired, the ERS management file verification unit 42i records the failure of the ERS management file and ERS file acquisition processing in the storage unit 43, and ends the processing flow.

  Next, the ERS management file verification unit 42i determines whether or not the file name having the first order in the data file to be processed is recorded in the acquired ERS management file (step S105).

  In the case where the file name of the first file in the processing target data file is not recorded in the ERS management file, the ERS management file verification unit 42i has been created once before being recorded in the acquired ERS management file. The ERS management file and the ERS file of the ERS management file are acquired from the data file storage system 3 (step S106).

  Here, when the ERS management file and the ERS file created one time before cannot be obtained, the ERS management file verification unit 42i indicates that the ERS management file and the ERS file acquisition process created one time ago have failed. It records in the memory | storage part 43 and complete | finishes a processing flow.

  Next, the ERS management file verification unit 42i, the hash value of the ERS management file created once before recorded in the ERS management file, and the hash of the ERS management file created one time before actually acquired It is determined whether or not the values match (step S107).

  If the hash value of the ERS management file created once before recorded in the ERS management file does not match the hash value of the ERS management file created once before actually obtained, the ERS management file verification is performed. The unit 42i records the mismatch of the hash values in the storage unit 43 (step S108), and ends the processing flow.

  On the other hand, if the hash value of the ERS management file created once before recorded in the ERS management file matches the hash value of the ERS management file created once before actually obtained, the step Return to S105.

  On the other hand, if it is determined in step S105 that the file name of the first data file in the processing target data file is recorded in the ERS management file, the ERS management file verification unit 42i performs the following processing for all the acquired ERS management files. Each concatenated hash data is created (step S109), and the time stamp validity verification process (existing ERS standard time stamp verification process) of the ERS management file is requested and executed (step S109). S110), it is determined whether or not the validity of the time stamp of the ERS management file has been successfully verified (step S111). In the verification process of the validity of the time stamp of the ERS management file performed here, the time stamp verification unit 42h receives the ERS management file, the ERS file of the ERS management file and the linked hash data as an input, and the ERS file of the ERS management file The root hash is reproduced using the hash tree information included in the, and it is confirmed whether or not the reproduced root hash matches the hash value in the time stamp. When the reproduced root hash matches the hash value in the time stamp, the time stamp verification unit 42h determines that the verification is successful and outputs the result. On the other hand, when the reproduced root hash does not match the hash value in the time stamp, the time stamp verification unit 42h determines that the verification has failed, and outputs the result.

  The hash tree information of the ERS file of the ERS management file includes linked hash data. Therefore, when the root hash is reproduced using the hash tree information included in the ERS file of the ERS management file, the time stamp verification unit 42h uses the input linked hash data instead of the hash value of the ERS management file. The linked hash data includes the hash value of the ERS management file and the hash value of the data file. When the data file necessary for creating the linked hash data is insufficient, the ERS management file verification unit 42 i acquires an additional data file from the data file storage system 3.

  When the verification of the validity of the time stamp of the ERS management file fails, the ERS management file verification unit 42i records the verification failure of the validity of the time stamp of the management file in the storage unit 43 (step S112), and the processing flow Exit. On the other hand, when the verification of the validity of the time stamp of the ERS management file is successful, the ERS management file verification unit 42i determines whether the verification process of the validity of the time stamp of the data file has been performed for all the ERS management files. (Step S113).

  If time stamp validity verification processing has not been performed for all ERS management files, the process returns to step S109. On the other hand, when the time stamp validity verification process is performed for all the ERS management files, the ERS management file verification unit 42i confirms the addition, deletion, or change of order of the data files to be processed (step S114). Then, it is determined based on the contents of all the acquired ERS management files whether or not the processing target data file has been added, deleted, or rearranged (step S115). Specifically, a data file that is not recorded in the ERS management file is stored in the data file storage system 3, a data file that is recorded in the ERS management file is deleted from the data file storage system 3, If the name also contains time-series information such as creation date and time, the order of the files has been changed by changing the file name, etc., and the addition or deletion of the data file to be processed or the change of order has occurred Judging. In addition, the alteration detection of each data file may make a verification request to the time stamp verification unit 42h again in addition to processing with the linked hash data.

  If no data file to be processed has been added, deleted, or reordered, the ERS management file verification unit 42i indicates that no data file to be processed has been added, deleted, or reordered. 43 (step S116), and the processing flow ends.

  On the other hand, when addition, deletion, or change of order of data files to be processed has occurred, the ERS management file verification unit 42i has added, deleted, or changed order of data files to be processed. Is stored in the storage unit 43 (step S117), and the processing flow ends.

  According to the processing flow shown in FIG. 6, the validity of the time stamp assigned to the ERS management file for a plurality of arbitrary files is verified from the ERS file as the verification file of the ERS management file. The authenticity of the management file is guaranteed. That is, the relationship between a plurality of arbitrary files included in the ERS management file is secured. As a result, it is possible to verify the relationship between a plurality of arbitrary files to which one time stamp is assigned and whether or not a file is added or deleted. Further, since the tampering detection based on the hash value of the arbitrary file is included in the verification process of the validity of the time stamp given to the management file, it is not necessary to verify the time stamp according to the conventional ERS standard for each arbitrary file. . In this way, since addition, deletion, or change of order of files can be detected while maintaining the relationship between a plurality of arbitrary files, the security of the electronic signature system can be improved.

  Here, an embodiment in another format of the ERS management file will be described. Similarly to the ERS management file described above, the ERS management file in another format lists file names according to a predetermined rule according to the relationship between a plurality of arbitrary files to which time stamps are added, and at the time of the previous time stamp assignment. The file name of the created ERS management file and the hash value of the contents of the ERS management file are recorded.

  In addition to these, in order to efficiently perform verification processing including checking the order relation for a part of an arbitrary file, a hash value of a plurality of arbitrary files is added to each file name. Are recorded in association with each other.

  When the ERS management file of this different format is used, it is not necessary to use the concatenated hash data in which the hash value of the arbitrary file is concatenated with the hash value of the ERS management file. In the case of not using the concatenated hash data obtained by concatenating the hash value of the arbitrary file with the hash value of the ERS management file, step S12 for creating the concatenated hash data is omitted in the processing flow shown in FIG. The file receiving unit 42b creates a hash tree having the hash values of the data file to be processed and the ERS management file at the end node. In step S15, the ERS file creating unit 42d corresponds to the hash value of each file. An ERS file for each data file and ERS management file is created from the hash tree and time stamp, and all the created ERS files are stored in the storage unit 43.

  Further, in the case of not using the concatenated hash data obtained by concatenating the hash value of the arbitrary file with the hash value of the ERS management file of this different format, step S109 for creating the concatenated hash data is omitted in the processing flow shown in FIG. The ERS management file verification unit 42i performs the verification process of the validity of the time stamp of the ERS management file (the time stamp verification process of the existing ERS standard) for each of the acquired ERS management files, the ERS management file and the ERS management file After specifying the ERS file of the file, the time stamp verification unit 42h is requested and executed. If the verification is successful, the hash value of the arbitrary file in the ERS management file is compared with the hash value obtained by calculation from the actually acquired arbitrary file, and it is confirmed that they match, and detection of falsification of the arbitrary file I do.

  The present invention is not limited to the above-described embodiment, and many changes and modifications can be made. For example, the case where an electronic signature system having an electronic signature server as a time stamp assigning device and a time stamp verification device according to the present invention is applied to an in-house system has been described. An electronic signature system having an electronic signature server as a stamp attaching device and a time stamp verification device can be applied. A file other than a data file can also be used as an arbitrary file.

  In the above embodiment, the case of using the time stamp assigning device and the time stamp verifying device corresponding to the ERS standard has been described. However, the time stamp giving device and the time stamp verifying device corresponding to the standard or standard technology other than the ERS standard. Can be used.

  FIG. 7 shows another example of the format of data stored in the data file storage system 3 of the electronic signature system when using a time stamp assigning device and a time stamp verification device corresponding to a standard or standard technology other than the ERS standard. As shown, verification files 1, 2, 3, and A are created independently of time stamp A for arbitrary files 1, 2, 3, and management file A to which time stamp A is assigned. May be.

  Similarly, in FIG. 7, even if the verification files 4, 5, B are created independently of the time stamp B for the arbitrary files 4, 5 and the management file B to which the time stamp B is assigned, respectively. Good.

  That is, the arbitrary files 1, 2, 3 and the management file A, the verification files 1, 2, 3 A and the time stamp A are associated with each other and stored in the data file storage system 3 and the storage unit 43. 5 and the management file B, the verification files 4, 5, B, and the time stamp B can be associated with each other and stored in the data file storage system 3 and the storage unit 43.

  Also, in order to clarify the time stamped system and improve the reliability of information, each file is given an electronic signature with the private key of the electronic signature system before creating a hash tree of the data file and management file It is also possible to verify the electronic signature of each file together with the time stamp verification process. The data file may be given an electronic signature by the data file creator.

  In the above embodiment, the case where the scheduler unit 42a is used to specify an arbitrary file to be time stamped or time stamp verified has been described. However, time stamp is given according to user input from the user terminal 1. A user input receiving unit that designates an arbitrary file that is a target or a time stamp verification target may be provided in the control unit 42. In this case, the file sending unit 42g adds or deletes the ERS management file generated by the time stamp assigning device, the ERS file (verification file) of each file, and the processing target data file output by the time stamp verifying device. Alternatively, information on whether or not the order is changed can be transmitted to the user terminal 1 through the communication I / F unit 41.

  In addition, the control unit 42 may be provided with a file designating unit that designates an arbitrary file to be time stamped or time stamp verified based on a file generation rule. In addition, the case where the scheduler unit 42a is used to specify the relationship between a plurality of arbitrary files specified as the time stamp assignment target has been described. It can be specified according to user input from or from file generation rules. Furthermore, the management file to be verified can be directly specified, or a certain arbitrary file can be specified, and the related management file can be specified and specified from the arbitrary file.

DESCRIPTION OF SYMBOLS 1 User terminal 2 Business system 3 Data file storage system 4 Electronic signature server 5, a Time stamp station 6 Communication network 11,21,31,41,51 Communication interface (I / F) part 12,22,32,42,52 Control unit 13 Input unit 14 Display unit 15, 23, 33, 43, 53 Storage unit 22a Business processing unit 22b Data file creation unit 42a Scheduler unit 42b Time stamp and file reception unit 42c ERS management file creation unit 42d ERS file creation unit 42e Electronic signature adding unit 42f Electronic signature verification unit 42g File sending unit 42h Time stamp verification unit 42i ERS management file verification unit t, t 'Time stamp

Claims (6)

A time stamp giving apparatus that issues a time stamp issuance request to a plurality of files to a time stamp authority, and assigns the time stamp issued by the time stamp authority to the plurality of files,
A file designating unit for designating a plurality of arbitrary files to be time stamped;
A management file creation unit for creating a management file including a relationship between the plurality of arbitrary files;
A time stamp acquisition unit that issues a request for issuing one time stamp to the plurality of arbitrary files and the management file to the time stamp authority, and acquires the time stamp issued by the time stamp authority;
For each of the plurality of arbitrary files and the management file, a verification file creation unit that creates a verification file that can verify the validity of the time stamp;
A time stamp assigning device comprising: The time stamp acquisition unit generates a hash tree using hash values of the plurality of arbitrary files and the management file, and uses the one hash value that is a root hash that is a vertex of the hash tree to generate the one time stamp. Issuance request,
2. The time according to claim 1, wherein the verification file creation unit creates the verification file including the time stamp and one of the plurality of arbitrary files or hash tree information related to the management file. Stamping device. The verification file creation unit stores the management file identification information in the storage unit every time the time stamp is acquired,
The said management file preparation part produces the said management file including the said identification information memorize | stored in the said memory | storage part at the time of the last time stamp acquisition, when giving a time stamp sequentially to several files. The time stamp assigning device described. A time stamp verification device for verifying the validity of the time stamp of a file given a time stamp,
Validity of a plurality of arbitrary files to which the time stamp is given, a management file to which the time stamp including at least a relationship between the plurality of arbitrary files is given, and a time stamp given to the arbitrary file and the management file A storage unit that stores a verification file capable of verifying the properties in association with each other;
Upon receiving the verification request, a time stamp verification unit that verifies the validity of the time stamp from the verification target file and the verification file associated with the file and outputs the verification result;
When the management file is a verification target, the time stamp verification unit is requested to verify the time stamp given to the management file, and if the verification result for the request is valid, the plurality of arbitrary files A management file verification unit that determines whether an arbitrary file is identified and stored in the storage unit based on the relationship between;
A time stamp verification apparatus comprising:   The management file verification unit creates concatenated data in which hash values of the plurality of arbitrary files are concatenated to a hash value of the management file based on a relationship between the plurality of arbitrary files, and includes the concatenated data and the request The time stamp verification apparatus according to claim 4, wherein the time stamp verification unit performs the following. The management file further includes hash values of the plurality of arbitrary files,
The management file verification unit, when the verification result for the request is valid, the hash value of the arbitrary file included in the management file and the hash value calculated from the arbitrary file stored in the storage unit 6. The time stamp verification apparatus according to claim 4, wherein the comparison results are used as a verification result of the validity of the time stamp assigned to the arbitrary file.

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