JP2008102573A - Document management system, apparatus and method, and document production apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten processing time for production and verification of a digital signature and enable verification of consistency among versions, in a document management apparatus for achieving version management of a document composed of a plurality of files. <P>SOLUTION: The document management apparatus 104 includes at least a CPU 202 and storage devices 203, 204, handles document data composed of a plurality of files as one unit, and stores an update history of the document data in the storage devices, wherein the storage devices 203, 204 store a hash value list including post-update file hash values as respective hash values of the plurality of files included in the document data and pre-update file hash values as respective hash values of pre-update files for the files, and the digital signature added to the hash value list. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a document management system, a document management apparatus, a document creation apparatus, and a document management method, and more particularly to a technique for detecting falsification of each version of a document in a system that performs version management of a document composed of a plurality of files. .

With the progress of IT technology in recent years, private enterprises and government offices are shifting from paper-based operations to electronic-based operations. In addition, the e-Document Act (official law name is “permitted by private businesses”) that allows electronic storage of documents (hereinafter referred to as “scanner storage”) that were required to be stored in paper due to legal regulations The Law Concerning the Use of Information and Communication Technology in Preservation of Documents ”was enforced in April 2005.
There are various types of documents that are subject to the e-document law, and the requirements for scanner storage differ depending on the documents. There are documents that require strict management using digital signatures and time stamps, from documents that only require readability.
In addition, as a document subject to the e-document law and having the strictest requirements, there is a national tax-related book document. Of the national tax-related books, documents that are directly related to the flow of money are required to ensure integrity by digital signatures, time stamps, and version management functions.
Among these, the version management function is a function for managing the history of registration, update, and deletion of electronic files. The version management function is mainly used for managing source code in program development, but is used as a means for preventing changes and deletion of electronic files in scanner storage of national tax related books. A method for realizing the version management function is disclosed in Non-Patent Document 1, for example.
Using the method of Non-Patent Document 1, a document composed of a plurality of files can be handled as one document, and the registration, update, and deletion history of each file included in the document, that is, version management is performed. realizable.
Patent Document 1 discloses a method for creating falsification detection information (for example, a digital signature) for each file as a method for guaranteeing the originality of a document composed of a plurality of files.
JP 2001-5728 A AIIM (The Association for Information and Image Management International): Document Management Architecture RFC3161-Internet X. 509 Public Key Infrastructure Time-Stamp Protocol (TSP)

  However, in the method disclosed in Patent Document 1, since a digital signature is created for each file, it is necessary to generate as many digital signatures as the number of files even when a plurality of files are registered as one document. is there. Therefore, a lot of processing time is required, and a lot of storage areas are required for storing digital signatures. Further, in Patent Document 1, a digital signature is assigned using a key stored in a server device, and a method for applying a signature on the client side is not disclosed. The scanner preservation of the national tax related book documents does not meet the requirements for the digital signature of the scanner preservation because it is a scanning person or supervisor. Furthermore, Patent Document 1 does not disclose means for guaranteeing consistency between versions. Although means for protecting various attribute data using a digital signature is disclosed, it cannot be said to be a means for guaranteeing consistency between versions.

  The present invention provides a document management method that solves the above-mentioned problems of the prior art, can reduce the processing time of creation and verification of a digital signature, and guarantees consistency between versions.

  In a document management system that realizes version management of a document composed of a plurality of files, the present invention calculates a hash value for each of the plurality of files constituting the document, and performs a hash value list on which these hash values are collected. One digital signature is given. According to the present invention, since the number of digital signatures to be created is one for a plurality of files, the digital signature creation time and verification are compared with the case of creating a digital signature for each file. You can save time. The digital signature can be created by any device regardless of whether it is a client device or a server device.

  In the present invention, the hash value list includes the hash value of the file before update and the hash value of the file after update. This makes it possible to verify which file the document creator or updater has created and which file has been updated. Further, the continuity between versions can be verified by comparing the file hash value before update between successive versions with the hash value of the file after update.

  That is, the present invention is a document management apparatus that includes at least a CPU and a storage device, handles document data composed of a plurality of files as one unit, and saves an update history of the document data in the storage device, The storage device includes a hash value list including an updated file hash value that is a hash value of each of a plurality of files included in the document data, and a pre-update file hash value that is a hash value of each of the files before the update of the file And a document management apparatus for storing the digital signature assigned to the hash value list.

  Further, the present invention is a document management apparatus in which the storage device stores a time stamp capable of guaranteeing time for the hash value list and / or the digital signature.

  The present invention includes a document creation device that includes at least a CPU and a storage device, handles document data composed of a plurality of files as a unit, and a document management device connected to the document creation device via a network. The document management apparatus is the document management apparatus described above, and receives a plurality of files, a hash value list, and a digital signature from the document creation apparatus, and receives each of the plurality of received files. Hash value is calculated for the received hash value list, and it is verified that the hash value that matches the calculated hash value is included in the updated file hash value of the received hash value list. And document management system that creates version attribute data including all file IDs that make up the document data It is a non.

  Furthermore, the present invention includes a document verification apparatus that includes at least a CPU and a storage device, handles document data composed of a plurality of files as a unit, and a document management apparatus connected to the document verification apparatus via a network. The document management apparatus is the document management apparatus described above, receives a file ID of a file to be verified from the document verification apparatus, and stores the storage apparatus based on the received file ID. A version attribute data associated with the file stored in the file, a hash value list and a digital signature are obtained from the acquired version attribute data, the obtained digital signature is verified, and a hash value for the file is obtained. Calculate and calculate the file hash value after updating the obtained hash value list. And a document management system to verify that it contains the hash value that matches the hash value.

  According to another aspect of the present invention, there is provided a document verification apparatus that includes at least a CPU and a storage device, handles document data composed of a plurality of files as a unit, and a document management apparatus connected to the document verification apparatus via a network. The document management apparatus is the document management apparatus described above, receives a document ID to be verified from the document verification apparatus, and saves it in the storage device based on the received document ID Obtained version attribute data, obtaining a hash value list, a digital signature, and a file ID from the obtained version attribute data, obtaining all files corresponding to the obtained file ID, verifying the digital signature, Calculate the hash value of each acquired file, and update the hash of the acquired hash value list The hash value list is verified by verifying that the hash value that matches the calculated hash value is included, and the hash value list is verified. A document that creates a list, verifies that the hash value that matches the calculated hash value is included in the second hash value list, and deletes the matched hash value from the second hash value list It is a management system.

  The present invention includes a document creation device that includes at least a CPU and a storage device, handles document data composed of a plurality of files as a unit, and a document management device connected to the document creation device via a network. The document management apparatus is the document management apparatus described above, receives a document ID from the document creation apparatus, and is stored in the storage device based on the received document ID. The latest version ID is obtained, a hash value list is obtained from the obtained version ID, the obtained hash value list is transmitted to the document creation device, the updated document ID and the updated file from the document creation device, Received file ID, hash value list, and digital signature, calculated hash value of each received file, received All the file IDs that make up the received hash value list, digital signature, and document data by verifying that the hash value that matches the calculated hash value is included in the updated file hash value of the hash value list Is a document management system for creating version attribute data including

  Furthermore, the present invention includes a document verification apparatus that includes at least a CPU and a storage device, handles document data composed of a plurality of files as a unit, and a document management apparatus connected to the document verification apparatus via a network. The document management apparatus is the document management apparatus described above, receives a document ID to be verified from the document verification apparatus, and saves it in the storage device based on the received document ID All version attribute data related to the document data being obtained, obtaining a hash value list and a digital signature from each obtained version attribute data, verifying the digital signature, and a hash value list between each version Version verification is performed by verifying consistency and performing inter-version consistency verification. Obtain two hash value lists, extract valid hash values from the older hash value list, create a second hash value list, and the hash values included in the second hash value list are all newer ones. This is a document management system that verifies that it is included in a hash value list.

  The present invention also receives a document ID from a document creation device connected via a network, acquires the latest version ID stored in the storage device based on the received document ID, and uses the acquired version ID. A hash value list is acquired, the acquired hash value list is transmitted to the document creation device, and an updated document ID, an updated file, a file ID, a hash value list, and a digital signature are received from the document creation device. Calculates the hash value of each received file, verifies that the hash value that matches the hash value obtained by calculation is included in the updated file hash value of the received hash value list, and the received hash value Document manager that creates version attribute data including all file IDs that compose list, digital signature, and document data It is a device.

  The present invention is a document creation apparatus that includes at least a CPU and a storage device and handles document data composed of a plurality of files as a unit, and is a document in which a document ID to be updated is connected via a network. Sends to the management device, receives the hash value list from the document management device, updates the file to create an updated file, calculates the hash value of the updated file, creates a new hash value list, and creates a new hash A document creation apparatus that assigns a digital signature to a value list and transmits a document ID, an updated file, a new hash value list, and a digital signature to the document management apparatus.

  Furthermore, the present invention is a method for managing a document created by a document creation device that includes at least a CPU and a storage device and handles document data composed of a plurality of files as a unit. File, hash value list, and digital signature received, calculated hash value for each of the received files, and updated file hash values in the received hash value list A document management method comprising: verifying that a hash value matching a hash value is included; and creating version attribute data including the hash value list, the digital signature, and all file IDs constituting the document data is there.

  According to the present invention, in a document management system that realizes version management of a document composed of a plurality of files, not only can a digital signature be generated on the client side, but also the digital signature can be generated and verified at high speed. Become. In addition, consistency between versions can be guaranteed.

The best mode for carrying out the present invention will be described.
Hereinafter, embodiments of a document management system, a document management apparatus, a document creation apparatus, and a document management method according to the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a diagram illustrating an example of a system configuration according to an embodiment of the present invention. As shown in FIG. 1, this system includes a document creation device 101, a verification device 102, a time stamp issuing device 103, and a document management device 104, and these devices are connected to each other via a network 105. Configured. Hereinafter, each of the devices 101 to 104 and the configuration and function of the devices will be described.

  In FIG. 1, a document creation apparatus 101 is a computer including at least a CPU (Central Processing Unit) and a storage device, and includes functional blocks such as a document registration unit 111 and a document update unit 112. The document registration unit 111 creates a digital signature for data created from a document made up of one or more files created by the user, and transmits the file and digital signature to the document management apparatus 104. Further, the document update unit 112 updates a document already registered in the document management apparatus 104. The format of the digital signature is disclosed in, for example, “RFC3852 Cryptographic Message Syntax (CMS)”.

  Next, the verification device 102 is a computer including at least a CPU and a storage device, and includes functional blocks such as a document verification unit 121. The document verification unit 121 issues a verification request for a file registered in the document management apparatus 104 and displays the verification result.

  Next, the time stamp issuing device 103 is a computer including at least a CPU and a storage device, and includes functional blocks such as a time stamp issuing unit 131. The time stamp issuing unit 131 issues a time stamp capable of proof of existence and integrity to the data transmitted from the document management apparatus 104 to the time stamp issuing apparatus 103. A method for realizing such a time stamp is disclosed in Non-Patent Document 2, for example.

  Next, the document management apparatus 104 is a computer including at least a CPU and a storage device, and includes functional blocks such as a document registration unit 141, a document update unit 142, and a document verification unit 143. Data such as document attribute data 144, version attribute data 145, file attribute data 146, and file 147 are stored in the storage device. The document registration unit 141 creates document attribute data 144, version attribute data 145, and file attribute data 146 from the file created by the document creation apparatus 101 and a digital signature, and stores them in the storage device. The document update unit 142 also changes, deletes, and adds files included in the registered document. The document verification unit 143 verifies the digital signature and time stamp stored in the storage device.

  FIG. 2 is a diagram showing an example of a general configuration of a computer according to the embodiment of the present invention. As shown in FIG. 2, the computer 201 includes a CPU 202, a main storage device 203, an auxiliary storage device 204, a network interface 205, an I / O interface 206, and the like that are connected to each other via an internal bus 207. The processing of the computer 201 is performed by the CPU 202 executing a program stored in the main storage device 203 or the like. Memory In this specification, when the main storage device 203 and the auxiliary storage device 204 are collectively referred to, they are simply referred to as “storage device”.

  Next, a flow of new document registration processing will be described with reference to FIG. This process is executed by the functions of the document registration unit 111 of the document creation apparatus 101 and the document registration unit 142 of the document management apparatus 104.

  In FIG. 3, the document creation apparatus 101 first calculates a hash value of each file and creates a hash value list (step S301). Then, a digital signature is given to the hash value list (step S302). Subsequently, the document name, file, file name, hash value list, and digital signature are transmitted to the document management apparatus 104 (step S303).

  Here, the hash value is a value created using a function that outputs a fixed-length value from input data of an arbitrary length called a hash function. For the purpose of ensuring the security of information, it is difficult for a hash function to find two different input data that give the same output value, and to find input data from the output value. It is preferable to use a function. The hash function calculation algorithm may be disclosed.

  Next, the document management apparatus 104 verifies the data received from the document creation apparatus 101 (step S304). This verification process includes each process of verifying the integrity of the hash value list using a digital signature and verifying that the hash value of each file is included in the hash value list. If these verification processes fail, the document management apparatus 104 returns an error to the document creation apparatus 101 and ends the new document registration process (not shown).

  Next, the document management apparatus 104 acquires a time stamp for the digital signature from the time stamp issuing apparatus 103 (step S305). The time stamp issuing device 103 issues a time stamp by executing the function of the time stamp issuing unit 131.

  As another embodiment, when the time stamp is not acquired, step S305 may be omitted. If the time guarantee is not required due to laws or system requirements, the time stamp need not be acquired.

  Furthermore, as another embodiment, the time stamp is assigned to both the digital signature and the hash value list, or only the hash value list, or the combined data of the received files, or the received files. Both the combined data and the digital signature may be used.

  Next, the document management apparatus 104 creates document attribute data 144, version attribute data 145, and file attribute data 146 (step S306). Then, the document attribute data 144, the version attribute data 145, the file attribute data 146, and the file 147 are stored in the storage device (step S307).

  As another embodiment, when a digital signature is not given, step S302 is omitted, and data excluding the digital signature is transmitted to the document management apparatus 104 in step S303. In step S 305, a time stamp for the hash value list is acquired from the time stamp issuing device 103.

  In the e-document method, depending on the type of document, when a digital signature is required, when both a digital signature and a time stamp are required, both the digital signature and the time stamp may be unnecessary. In addition, the digital signature assignment target and the time stamp assignment target are also specified in the e-document method. The present invention can be applied to any case.

  Next, an example of a hash value list created by the document creation device 101 when a new document is registered will be described with reference to FIG. 4A shows an example of a hash value list created at the time of new registration, and FIG. 4B shows an example of a hash value created at the time of update. As shown in FIGS. 4A and 4B, the hash value list is composed of an updated file hash value and an updated file hash value.

  Here, the updated file hash value is a hash value of a newly added file or an updated file. The pre-update file hash value is a hash value of the file before update when the file is updated. When a new document is registered, there is no pre-update file, so “0” is designated as the pre-update file hash value. Further, when updating a document, for a file whose contents have been changed, both the pre-update file hash value and the post-update file hash value are values other than “0”. In addition, the hash value of the deleted file is not included in the hash value list.

  Further, the hash value list may be sorted by the updated file hash value or the pre-update file hash value before the digital signature or time stamp is given. By sorting, it is possible to increase the speed of searching for hash values included in the hash value list.

  Further, by including only the hash value of the file in the hash value list, the system of the present invention can be realized in a system-independent format. For example, when system-specific information such as a file ID is included, it is very difficult to shift to another company's system. However, in the present invention, system migration can be realized more easily.

  In addition, by adding the digital signature of the file creator to the hash value list in the format as shown in FIG. 4, it is possible to clarify who created and which file was updated.

  Next, an example of document attribute data 144, version attribute data 145, and file attribute data 146 stored in the document management apparatus 104 will be described with reference to FIG.

  The document attribute data 144 is one piece of data for a document. The document ID, the document name, the creation date / time, the last update date / time, and the reference data (version ID) for version attribute data for managing the version information of the document ) And other data. There are as many version IDs as the number of document versions. For example, if the current document version is 3, there are three version IDs.

  The version attribute data 145 is data created when a document is newly registered or updated, and manages version ID, version number, document ID, creation date / time, hash value list, digital signature, time stamp, and file information. It has data such as reference data (file ID) to the file attribute data. There are as many file IDs as the number of files constituting the version. For example, when there are five files constituting a version, there are five file IDs.

  The file attribute data 146 is data created when a file is added / updated, and has data such as a file ID, a previous version file ID, a version ID, a file hash value, and a file name. The previous version file ID designates “0” when a file is added. The version ID is a version ID of version attribute data created when this file is newly registered or added.

  Next, referring to FIG. 6, the relationship among the document attribute data 144, the version attribute data 145, the file attribute data 146, and the file 147 is shown.

  As shown in FIG. 6, the document attribute data 144 includes reference information (version ID) to one or more version attribute data 145. The version attribute data 145 includes reference information (file ID) to one or more file attribute data 146. The file attribute data 146 referred to by the version attribute data 145 includes reference information (file IDs) for the file attributes of all the files constituting the version. The file attribute data 146 includes a reference to one file.

  The file attribute data 146 is referenced from one or more version attribute data. When the version is upgraded from the old version to the new version, the file attribute data 146 of the file that has not been updated or deleted is referred to from both the old version and the new version version attribute data 145. When updated or deleted, the file attribute data 145 is not referenced from the version attribute data 145 of the new version.

  By providing the relevance as shown in FIG. 6, it is possible to search a version list of a certain document or trace the update history of a specific file.

  Document attribute data, file attribute data, version attribute data, and files are preferably managed in a relational database from the viewpoint of searchability. For the purpose of preventing tampering, it is desirable to store version attribute data, file attribute data, and a file in a storage device (eg, CD-R, DVD-R, etc.) that is difficult to rewrite or a database area that has a tamper-proof function. .

  Next, a flow of verification processing for one file will be described with reference to FIG. This process is executed by the functions of the document verification unit 121 of the verification device 102 and the document verification unit 143 of the document management device 104.

  In FIG. 7, the verification apparatus 102 first transmits the verification target file ID to the document management apparatus 104 (step S701).

  Next, the document management apparatus 104 refers to the file attribute data 146 from the file ID received from the verification apparatus 102, and acquires the version ID (step S702). Then, the version attribute data 145 is referred to from the version ID, and a hash value list, a digital signature, and a time stamp are acquired (step S703). Subsequently, the file 146 corresponding to the file ID is acquired (step S704).

  Next, the document management apparatus 104 verifies the digital signature and the time stamp (step S705). Digital signature verification is performed using a hash value list and a digital signature. The public key necessary for verifying the digital signature is included in the digital signature. In addition, the time stamp is verified using the time stamp addition target and the time stamp. The subject to which the time stamp is given differs depending on the system requirements. For example, only a digital signature, a digital signature and a hash value list, or only a hash value list can be considered. If verification of the digital signature or time stamp fails, the document management apparatus 104 returns an error to the verification apparatus 102 and ends the verification process (not shown).

  As another embodiment, when a digital signature is not created at the time of registration, the digital signature verification process in step S705 is omitted. Similarly, if a time stamp has not been created at the time of registration, the time stamp verification processing in step S705 is omitted. Also, only digital signatures or time stamps alone may be verified. It may be configured so that it can be selectively specified by a request from the verification device 102.

  Next, the document management apparatus 104 calculates a hash value of the file (step S706). Then, it is checked whether or not the calculated hash value is included in the hash value list (step S707). This check refers to the updated file hash value column in the hash value list.

  Next, the document management apparatus 104 transmits the verification result to the verification apparatus 102 (step S708). Then, the verification device 102 displays the received verification result (step S709).

  Next, the flow of verification processing for all files included in a certain version will be described with reference to FIG. This process is executed by the functions of the document verification unit 121 of the verification device 102 and the document verification unit 143 of the document management device 104.

  In FIG. 8, the verification apparatus 102 first transmits the document ID and version ID to be verified to the document management apparatus (step S801).

  Next, the document management apparatus 104 refers to the document attribute data 144 from the document ID received from the verification apparatus 102, and acquires the version attribute data 145 of the specified version ID (step S802). Then, the hash value list, digital signature, time stamp, and file ID are acquired with reference to the version attribute data 145 (step S803). Subsequently, all the files corresponding to the file ID are acquired (step S804).

  Next, the document management apparatus 104 verifies the digital signature and the time stamp (step S805). Digital signature verification is performed using a hash value list and a digital signature. The public key necessary for verifying the digital signature is included in the digital signature. In addition, the time stamp is verified using the time stamp addition target and the time stamp. The subject to which the time stamp is given differs depending on the system requirements. For example, only a digital signature, a digital signature and a hash value list, or only a hash value list can be considered. If verification of the digital signature or time stamp fails, the document management apparatus 104 returns an error to the verification apparatus 102 and ends the verification process (not shown).

  As another embodiment, when the digital signature is not created at the time of registration, the digital signature verification process in step S805 is omitted. Similarly, if the time stamp has not been created at the time of registration, the time stamp verification processing in step S805 is omitted. Also, only digital signatures or time stamps alone may be verified. It may be configured so that it can be selectively specified by a request from the verification device 102.

  Next, the document management apparatus 104 calculates a hash value of each file (step S806). Then, it is checked whether all hash values are included in the hash value list. (Step S807). A specific check method will be described later.

  Next, the document management apparatus 104 transmits the verification result to the verification apparatus 102 (step S808). Then, the verification device 102 displays the received verification result (step S809).

  Next, a processing flow for checking whether or not all the hash values in step S807 in FIG. 8 are included in the hash value list will be described with reference to FIG.

  In FIG. 9, the document management apparatus 104 extracts a valid hash value from the hash value list and creates a second hash value list (step S901). In this process, either the updated file hash value or the pre-update file hash value is extracted from each row of the hash value list. If the post-update file hash value is not “0”, the post-update file hash value is extracted, and if it is “0”, the pre-update file hash value is extracted. The second hash value list is a list in which the extracted hash values are arranged in a line.

  Next, the document management apparatus 104 sorts the second hash value list (step S902). By sorting, the search speed when comparing hash values can be increased.

  Next, the document management apparatus 104 substitutes the number N of files included in the version into the internal variable i (step S903). Then, one hash value is extracted from the hash values calculated in step S806, and it is checked whether the hash value is included in the second hash value list (step S904). If it is not included in the second hash value list, the process proceeds to step S908 (not shown).

  Next, the document management apparatus 104 deletes the hash value matched in step S904 from the second hash value list (step S905). Then, 1 is subtracted from the value of the internal variable i (step S906). Subsequently, it is determined whether or not the value of the internal variable i is larger than “0”. If it is greater than “0”, the process returns to step S904, and if not, the process proceeds to step S908 (step S907).

  Next, a hash value comparison result is returned (step S908). As a result of the comparison, if the value of the internal variable i is “0” and the hash value is not included in the second hash value list, it is a success, and otherwise it is a failure. In addition, in the case of a failure, information such as the hash value of a file that does not match or the number of hash values included in the second hash value list and the number of files N may be returned as supplementary information.

  Next, a document update process flow will be described with reference to FIG. This process is executed by the functions of the document update unit 112 of the document creation apparatus 101 and the document update unit 142 of the document management apparatus 104.

  In FIG. 10, the document creation apparatus 101 first transmits the document ID to be updated to the document management apparatus 104 (step S1001).

  Next, the document management apparatus 104 refers to the ornament attribute data 144 from the document Id received from the document creation apparatus 101, and acquires the latest version ID (step S1002). Then, the version attribute data 145 is referred to from the version ID, a hash value list is acquired, and transmitted to the document creation apparatus 101 (step S1003).

  Next, the document creation apparatus 101 calculates a hash value of the updated file and creates a hash value list (step S1004). An example of the hash value list at the time of updating is shown in FIG.

  Next, the document creation apparatus 101 gives a digital signature to the hash value list (step S1005). Then, the document ID, file, file ID, hash value list, and digital signature are transmitted to the document management apparatus 104 (step S1006).

  Next, the document management apparatus 104 verifies the received data (step S1007). This verification process includes each process of verifying the integrity of the hash value list using a digital signature and verifying that the hash value of each file is included in the hash value list. If these verification processes fail, the document management apparatus 104 returns an error to the document creation apparatus 101 and ends the document update process (not shown).

  Next, the document management apparatus 104 acquires a time stamp for the digital signature from the time stamp issuing apparatus 103 (step S1008). The time stamp issuing device 103 issues a time stamp by executing the function of the time stamp issuing unit 131.

  As another embodiment, when the time stamp is not acquired, step S305 may be omitted. If the time guarantee is not required due to laws or system requirements, the time stamp need not be acquired. In still another embodiment, the time stamp may be assigned to both the digital signature and the hash value list, or only the hash value list.

  Next, the document management apparatus 104 creates version attribute data 145 and file attribute data 146, and updates the document attribute data 144 (step S1009). Then, the file 147, version attribute data 145, and file attribute data 146 are stored in the storage device (step S1010).

  As another embodiment, when a digital signature is not given, step S1005 is omitted, and data excluding the digital signature is transmitted to the document management apparatus 104 in step S1006. In step S1008, a time stamp for the hash value list is acquired from the time stamp issuing device 103.

  Next, a flow for verifying continuity between versions will be described with reference to FIG. This process is executed by the functions of the document verification unit 121 of the verification device 102 and the document verification unit 142 of the document management device 104.

  In FIG. 10, in the verification process for all the files included in the version, it cannot be guaranteed that the files included in the version before the update have not been tampered with. The process shown in FIG. 11 is a process that compensates for this, and verifies that the update of the document was performed by a correct process.

  In FIG. 11, the verification apparatus 102 first transmits the document ID to be verified to the document management apparatus 104 (step S1101).

  Next, the document management apparatus 104 refers to the document attribute data 144 from the received document ID, and acquires all version IDs (step S1102). Then, the version attribute data 145 corresponding to each version ID is acquired (step S1103). Subsequently, a hash value list, a digital signature, and a time stamp are acquired from each version attribute data 145 (step S1104).

  Next, the document management apparatus 104 verifies the digital signature and the time stamp for each version (step S1105). Digital signature verification is performed using a hash value list and a digital signature. The public key necessary for verifying the digital signature is included in the digital signature. In addition, the time stamp is verified using the time stamp addition target and the time stamp. If verification of the digital signature or time stamp fails, the document management apparatus 104 returns an error to the verification apparatus 102 and ends the verification process (not shown).

  As another embodiment, when the digital signature is not created at the time of registration, the digital signature verification process in step S805 is omitted. Similarly, if the time stamp has not been created at the time of registration, the time stamp verification processing in step S805 is omitted. Also, only digital signatures or time stamps alone may be verified. It may be configured so that it can be selectively specified by a request from the verification device 102.

  Next, the document management apparatus 104 checks the consistency of the hash value list between versions (step S1106). A specific check method will be described later.

  Next, the document management apparatus 104 transmits the verification result to the verification apparatus 102 (step S1107). Then, the verification device 102 displays the verification result (step S1108).

  Next, a method for verifying the consistency of the hash value list between versions in step S1106 in FIG. 11 will be described with reference to FIG.

  In FIG. 12, the document management apparatus 104 acquires a hash value list for each of version (M) and version (M + 1) (step S1201). Here, “M” represents a version number, and in this step, a hash value list of two consecutive versions is acquired.

  Next, the document management apparatus 104 extracts a valid hash value from the hash value list of version (M) and creates a second hash value list (M) (step S1202). In this process, either the updated file hash value or the pre-update file hash value is extracted from each row of the hash value list. If the post-update file hash value is not “0”, the post-update file hash value is extracted, and if it is “0”, the pre-update file hash value is extracted. The second hash value list is a list in which the extracted hash values are arranged in a line.

  Next, the document management apparatus 104 verifies whether the pre-update file hash values of the hash value list of version (M + 1) are all included in the second hash value list (M) (step S1203).

  The above processing is executed between all successive versions.

  As described above, in a document management system that realizes version management of a document composed of a plurality of files, not only can a digital signature be generated on the client side, but also the digital signature can be generated and verified. . In addition, consistency between versions can be guaranteed. And it can apply to the use which guarantees the authenticity of the change history of the document in a document management system.

It is the figure which showed the example of the system configuration | structure which concerns on embodiment of this invention. It is the figure which showed the example of the general structure of the computer which concerns on embodiment of this invention. It is the figure which showed the flow of the new registration process of the document which concerns on embodiment of this invention. It is the figure which showed the example of the hash value list which concerns on embodiment of this invention. It is a figure showing an example of each data of document attribute data, version attribute data, and file attribute data concerning an embodiment of the present invention. It is the figure which showed the relationship between the document attribute data which concerns on embodiment of this invention, version attribute data, file attribute data, and a file. It is the figure which showed the flow of the verification process of one file which concerns on embodiment of this invention. It is the figure which showed the flow of the verification process of all the files contained in the version which concerns on embodiment of this invention. It is the figure which showed the flow of the comparison process of the hash value of a file and hash value list which concerns on embodiment of this invention. It is the figure which showed the flow of the update process of the document which concerns on embodiment of this invention. It is the figure which showed the flow of the verification process of the continuity between versions which concerns on embodiment of this invention. It is the figure which showed the flow of the verification process of the consistency of the hash value list between versions which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Document creation apparatus 102 Verification apparatus 103 Time stamp issuing apparatus 104 Document management apparatus 105 Network 111 Document registration part 112 Document update part 121 Document verification part 131 Time stamp issue part 141 Document registration part 142 Document update part 143 Document verification part 144 Document attribute Data 145 Version attribute data 146 File attribute data 147 File 201 Computer 202 CPU
203 Main Storage Device 204 Auxiliary Storage Device 205 Network Interface 206 I / O Interface 207 Internal Bus

Claims (10)

A document management device comprising at least a CPU and a storage device, handling document data composed of a plurality of files as a unit, and storing an update history of the document data in the storage device,
The storage device includes a hash value list including an updated file hash value that is a hash value of each of a plurality of files included in the document data, and a pre-update file hash value that is a hash value of each of the files before the update of the file And a digital signature assigned to the hash value list. The document management apparatus according to claim 1,
The document management apparatus, wherein the storage device stores a time stamp capable of guaranteeing a time for the hash value list and / or the digital signature. A document management system comprising at least a CPU and a storage device, a document creation device that handles document data composed of a plurality of files as a unit, and a document management device connected to the document creation device via a network. And
3. The document management apparatus according to claim 1, wherein the document management apparatus receives a plurality of files, a hash value list, and a digital signature from the document creation apparatus, and hashes each of the received plurality of files. The hash value list, the digital signature, and the document are calculated by verifying that the hash value that matches the hash value obtained by calculating is included in the updated file hash value of the received hash value list. A document management system for creating version attribute data including all file IDs constituting data. A document management system comprising at least a CPU and a storage device, a document verification device that handles document data composed of a plurality of files as a unit, and a document management device connected to the document verification device via a network. And
The document management apparatus according to claim 1 or 2, wherein the document management apparatus receives a file ID of a file to be verified from the document verification apparatus, and stores the file ID in the storage device based on the received file ID. The version attribute data related to the file and the file obtained, the hash value list and the digital signature are obtained from the obtained version attribute data, the obtained digital signature is verified, and the hash value for the file is calculated. A document management system that verifies that a hash value that matches a hash value obtained by calculation is included in an updated file hash value of the obtained hash value list. A document management system comprising at least a CPU and a storage device, a document verification device that handles document data composed of a plurality of files as a unit, and a document management device connected to the document verification device via a network. And
The document management apparatus according to claim 1 or 2, wherein the document management apparatus receives a document ID to be verified from the document verification apparatus, and is stored in the storage device based on the received document ID. Version attribute data is acquired, a hash value list, a digital signature, and a file ID are acquired from the acquired version attribute data, all files corresponding to the acquired file ID are acquired, the digital signature is verified, and acquired. The hash value of each file is calculated, and the hash value list is verified by verifying that the hash value that matches the calculated hash value is included in the updated file hash value of the acquired hash value list. ,
When performing hash value list verification, a second hash value list is created from the hash value list, and the second hash value list includes a hash value that matches the hash value obtained by the calculation. A document management system that verifies and deletes a matched hash value from the second hash value list. A document management system comprising at least a CPU and a storage device, a document creation device that handles document data composed of a plurality of files as a unit, and a document management device connected to the document creation device via a network. And
The document management apparatus according to claim 1 or 2, wherein the document management apparatus receives a document ID from the document creation apparatus, and is stored in the storage device based on the received document ID. Acquires a version ID, acquires a hash value list from the acquired version ID, transmits the acquired hash value list to the document creation device, and updates the document ID, updated file, and file ID from the document creation device. Hash value list and digital signature are received, the hash value of each received file is calculated, and the hash value that matches the hash value obtained by calculating in the updated file hash value of the received hash value list is A version including all the file IDs constituting the received hash value list, digital signature, and document data is verified. Document management system, characterized in that to create the attribute data. A document management system comprising at least a CPU and a storage device, a document verification device that handles document data composed of a plurality of files as a unit, and a document management device connected to the document verification device via a network. And
The document management apparatus according to claim 1 or 2, wherein the document management apparatus receives a document ID to be verified from the document verification apparatus, and is stored in the storage device based on the received document ID. All version attribute data related to existing document data, obtain a hash value list and digital signature from each obtained version attribute data, verify the digital signature, and consistency of hash value lists between versions To verify version consistency,
When performing inter-version consistency verification, two hash value lists with successive versions are acquired, a valid hash value is extracted from the older hash value list, a second hash value list is created, and the second list A document management system that verifies that all hash values included in the hash value list are included in the new hash value list. The document management apparatus according to claim 1 or 2,
Receives a document ID from a document creation apparatus connected via a network, acquires the latest version ID stored in the storage device based on the received document ID, and acquires a hash value list from the acquired version ID The acquired hash value list is transmitted to the document creation device, and the updated document ID, the updated file, the file ID, the hash value list, and the digital signature are received from the document creation device. Calculates the hash value, verifies that the hash value that matches the calculated hash value is included in the updated file hash value of the received hash value list, and receives the hash value list, digital signature, and document A document tube characterized by creating version attribute data including all file IDs constituting the data Apparatus. A document creation device including at least a CPU and a storage device, and handling document data composed of a plurality of files as one unit,
A document ID to be updated is transmitted to a document management apparatus connected via a network, a hash value list is received from the document management apparatus, a file is updated to create an updated file, and a hash value of the updated file To create a new hash value list, assign a digital signature to the new hash value list, and send the document ID, the updated file, the new hash value list, and the digital signature to the document management apparatus. Document creation device characterized by A method of managing a document created by a document creation device that includes at least a CPU and a storage device and handles document data composed of a plurality of files as a unit,
Receiving a plurality of files, a hash value list, and a digital signature from the document creation device; calculating a hash value for each of the plurality of received files; and the updated file hash value of the received hash value list Verifying that a hash value that matches the calculated hash value is included, and creating version attribute data including the hash value list, the digital signature, and all file IDs constituting the document data A document management method characterized by comprising:

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