JP4699175B2 - Time stamp information verification support server device, time stamp information verification support method, computer program, and time stamp information verification support device - Google Patents

Description

  The present invention relates to a technique that supports verification of validity of time stamp information attached to electronic data.

Time stamp technology is a technology that cryptographically proves that electronic data exists at a certain time and has not been tampered with since then. In this technique, the authenticity and the like can be ensured by verifying time stamp data (time stamp token: TST) generated by an organization that issues a time stamp called a time stamp authority (TSA). However, in order to verify TST, processing according to the type of TST is necessary, and the burden on the auditor is large. In order to solve this problem, there is a model in which a time stamp verification server (VA) capable of verifying various types of TSTs performs verification processing, returns the verification result to the auditor, and the auditor examines the verification result. Exists (Patent Document 1).
JP 2005-20651 A

  The only items that can be verified by the verification technique described in Patent Document 1 are verification of the validity of the TST, such as verification of the format and effectiveness of the TST and verification of the correspondence between the TST and the electronic document. What can be determined from the verification result is that the target electronic document data has not been tampered with after the verification process has been executed by the TSA at the time recorded as TST data.

  However, the time at which the auditor is interested is not the time recorded as TST data, but the time recorded in the electronic document. Therefore, in order to determine the authenticity of the time recorded in the electronic document, it is confirmed whether or not the difference between the time recorded as TST data and the time recorded in the electronic document is acceptable. There is a need.

  The auditor displays the electronic document data on the screen, visually confirms the location related to the time, calculates the difference between the confirmed time and the time recorded as TST data, and the difference is included in the document. It can be done in the order of estimating how much it affects the credibility of the described matters and judging its credibility. However, this creates a heavy burden on the auditor.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technology that supports the determination of the authenticity of the date and time recorded in an electronic document.
Another object of the present invention is to provide an electronic document audit support technology that places little burden on the auditor.

In order to achieve the above object, a time stamp information verification support server device according to the first aspect of the present invention provides:
Receiving means for acquiring an electronic document sent from the client device and time stamp information proving the date and time when the electronic document existed;
Reading means for reading information about the date and time in the electronic document received by the receiving means;
Difference calculating means for calculating a difference between the date and time indicated by the date and time information read by the reading means and the date and time indicated by the time stamp information;
Transmitting means for transmitting difference information indicating the difference calculated by the difference calculating means to the client device;
It is characterized by providing.

  The reading unit may include, for example, a character recognizing unit that recognizes characters of the electronic document, and a date / time information reading unit that reads information related to the date / time from characters recognized by the character recognizing unit.

  For example, the receiving unit receives range designation information for designating a reading range of the electronic document from the client device, and the reading unit is designated by the range designation information in the electronic document received by the receiving unit. Read information about the date and time in the specified range.

  For example, the transmission unit transmits an index indicating the degree of difference calculated by the difference calculation unit to the client device.

  A format verification unit that verifies the format of the electronic document received by the reception unit, and the date and time indicated by the generation date and time information added to the file name of the electronic document received by the reception unit. And at least one of date verification means for determining whether the date is earlier than the date may be further arranged.

In order to achieve the above object, a time stamp information verification support method according to the second aspect of the present invention includes:
The document acquisition means acquires the electronic document to be verified and the time stamp information of the electronic document,
Reading means reads information on the date and time in the acquired electronic document,
The difference calculation means calculates the difference between the date and time indicated by the read date and time information and the date and time indicated by the time stamp information,
A transmission means transmits difference information indicating the calculated difference.
It is characterized by that.

In order to achieve the above object, a computer program according to a third aspect of the present invention is:
On the computer,
Obtain the electronic document to be verified and the time stamp information of the electronic document,
Read the date and time information in the acquired electronic document,
Calculate the difference between the date and time indicated by the read date and time information and the date and time indicated by the time stamp information,
Sending difference information indicating the calculated difference,
Run the action.
In order to achieve the above object, a time stamp information verification support apparatus according to the fourth aspect of the present invention,
A document acquisition means for acquiring an electronic document to be verified and time stamp information of the electronic document;
Reading means for reading information on the date and time in the electronic document acquired by the document acquisition means;
Difference calculating means for calculating a difference between the date and time indicated by the date and time information read by the reading means and the date and time indicated by the time stamp information;
Transmitting means for transmitting difference information indicating the difference calculated by the difference calculating means;
It is characterized by providing.

  According to the present invention, since the difference between the date and time indicated by the date and time information in the electronic document and the date and time indicated by the time stamp information is automatically calculated and provided, the burden on the auditor is small.

  The time stamp verification apparatus according to the embodiment of the present invention will be described below.

  As shown in FIG. 1, the time stamp information verification apparatus according to the embodiment of the present invention includes a plurality of user terminals 1, an inspector terminal 2, and time stamp information verification connected via a communication network N. The apparatus 3 and the time stamp server apparatus 4 are comprised.

  The communication network N is a network that performs data transmission based on a predetermined communication program such as TCP / IP (Transmission Control Protocol / Internet Protocol). The communication network N interconnects the user terminal 1 and the inspector terminal 2, the time stamp information verification device 3, and the time stamp server device 4, and mediates data communication therebetween.

  The user terminal 1 and the inspector terminal 2 are configured by an information processing apparatus such as a personal computer having a network communication function. The user terminal 1 is used by a person (user) who creates certificate documents widely, such as a public office or a general company, and the auditor terminal 2 is used by an auditor. Regardless of whether the user and the auditor are the same company or the like, the user and the auditor may be the same person. Therefore, the user terminal 1 and the auditor terminal 2 may be one information processing apparatus.

  The time stamp server device 4 includes a certificate (TST (Time Stamp) that proves that the electronic document exists in the electronic document (or message digest (hash value) of the electronic document) transmitted from the user terminal 1. Token)) is generated and issued, and is provided to the user terminal 1. In the time stamp server device 4, a message digest of the electronic document may be generated and included in the TST.

  The time stamp information verification device 3 is a device for verifying an electronic document and its TST. Physically, as shown in FIG. 2, the time stamp information verification device 3 includes a control device 21, a communication unit 22, and a storage unit 23. Composed.

  The control device 21 includes, for example, a CPU (Central Processing Unit) and a RAM (Random Access Memory) serving as a work area, and executes various control operations described later.

  The communication unit 22 includes, for example, a communication device such as a NIC (Network Interface Card), a router, or a modem. The communication unit 22 connects the time stamp information verification device 3 and the communication network N, and communicates with the user terminal 1, the inspector terminal 2, the time stamp information verification device 3, and the time stamp server device 4 via the communication network N. Send and receive various information between them.

  The storage unit 23 includes a hard disk device and the like, and stores a processing program of the control unit 23 and various data.

Functionally, the time stamp information verification apparatus 3 having the configuration shown in FIG. 2 has the configuration shown in FIG. That is, the time stamp information verification device 3 includes a control unit 321, a reception unit 31 and a transmission unit 32, a storage unit 323, a verification unit 33, and a difference verification unit 34.
The verification unit 33 includes a time stamp format verification unit 331, a time stamp validity verification unit 332, and a correspondence verification unit 333.
The difference verification unit 34 includes a reading position designation unit 301, a reading unit 302, a date / time data candidate extraction unit 303, a difference time calculation unit 304, and a verification result output creation unit 305.

  The reception unit 31 and the transmission unit 32 are configured by the communication unit 22. The receiving unit 31 receives a pair of an electronic document and a TST from the inspector terminal 2 via the communication network N. The transmission unit 32 transmits information for verification (a verification result and a difference calculation result described later) generated by the time stamp information verification device 3 to the inspector terminal 2 via the communication network N.

  The control unit 321 includes a basic part of the control device 21 and the operation program. The control unit 321 supplies the electronic document and TST received via the receiving unit 31 to the verification unit 33 and the difference verification unit 34, and verifies the pair of the electronic document and TST, respectively.

  The time stamp format verification unit 331 determines whether or not the TST data format is a predetermined format, and further whether or not the TST data format is a predetermined document format. For example, it is determined whether or not the TST is a message digest, date, and electronic signature format, whether the date format matches, whether the correspondence between the data and the error check code is appropriate, or the like.

  The time stamp validity verification unit 332 verifies the authenticity of the electronic document and the TST by determining the front-to-back relationship between the creation date and time of the electronic document and the TST certification date and time attached by the time stamp server device 4. . For example, if the document creation date and time is later than the TST certification date and time, it can be verified that some tampering exists. Specifically, for example, the time stamp validity verification unit 332 performs verification by comparing the creation or update date / time indicated by the date / time information mechanically attached to the header of the electronic document by the TST certification date / time. Perform the action.

  The correspondence verification unit 333 verifies whether or not the correspondence between the electronic document and the TST is correct, for example, by checking a message digest.

  When the reading position designation unit 301 designates a position (that is, a character recognition range) for reading character information of the electronic document designated by the inspector, the reading position designation unit 301 receives this information from the control unit 321 and reads the position on the electronic document. Is specified.

  The reading unit 302 reads an electronic document based on the reading position information specified by the reading position specifying unit 301, recognizes characters, creates a format file (plain text) such as a text file format, and the result is the control unit 321. Send to.

  The date / time data candidate extraction unit 303 includes only the data in the date format such as MM / DD / YYY / YYY / MM / DD / YYYY / MM / DD / YY in the text data read by the reading unit 302. Is extracted as plain text, and the result is sent to the control unit 321 as date information data candidates.

  The difference time calculation unit 304 calculates the difference between the date / time indicated by the date / time data candidate and the certification date / time described in the TST. In the difference time calculation unit 304, if the difference between the certification date and time indicated in the TST and the date and time indicated by the date and time data candidate is 0 day or more and less than 2 days, “OK”, 2 days or more, or a negative value For example, after adding character information such as “NG”, the result is sent to the control unit 321.

  The verification result output creation unit 305 creates a difference record indicating a difference between each date information in the electronic document and the date and time indicated by the time information described in the TST, and sends the difference record to the control unit 321.

  Next, an operation of processing for the inspector to use the time stamp information verification apparatus 3 of this embodiment will be described with reference to FIG.

First, as a premise, the user operates the user terminal 1 to transmit the electronic document to be date certified or the hash value data of the electronic document to the time stamp server device 4 via the communication network N. The format of the electronic document is arbitrary.
The time stamp server device 4 creates a message digest of the image data of the received electronic document as necessary, adds date information to the message digest, performs an electronic signature using its own private key, and generates a TST. Return it to the requesting user terminal. The electronic document and the TST may be returned in association with each other.

Subsequently, it is assumed that there is a need for a commercial transaction or the like between a user who has received TST and another user, and another user needs to check the authenticity of the electronic document and the TST.
In this case, the user transfers the electronic document and the TST to another user (hereinafter referred to as an auditor).
The inspector operates his / her user terminal 1 (that is, the inspector terminal 2) to transmit a verification request to the time stamp information verification apparatus 3 via the communication network N, and then the electronic document And TST pair. At this time, the auditor appropriately sets the reading range (character recognition range) of the electronic document as necessary.

When the control unit 321 of the time stamp information verification apparatus 3 receives a request from the inspector terminal 2 via the reception unit 31, the control unit 321 starts the date check process illustrated in FIG.
First, the control unit 321 takes in the electronic document and TST transmitted from the inspector terminal 2 via the receiving unit 31 (step S201).

  Upon receiving the electronic document and TST, the control unit 321 temporarily stores it in the memory, supplies it to the verification unit 33, and performs verification (step S202).

  First, the time stamp format verification unit 331 in the verification unit 33 determines whether or not the TST file format and data format are predetermined formats. For example, whether or not TST is in the form of message digest, date, and electronic signature, whether the date and time of certification is in the format of year YY year MM month DD date time minute second, whether the number of digits matches, data and error check Check the correspondence with the code.

  The time stamp validity verification unit 332 verifies the authenticity of the electronic document and the TST by determining the front-to-back relationship between the creation date and time of the electronic document and the TST certification date and time attached by the time stamp server device 4. . For example, if the document creation date and time is later than the TST certification date and time, it can be verified that some tampering exists.

  The correspondence verification unit 333 verifies whether or not the correspondence relationship between the electronic document and the TST is correct, for example, by checking the link relationship between the two documents and the message digest of the electronic document included in the TST.

  The format verification unit 331, the time stamp validity verification unit 332, and the correspondence verification unit 333 supply the verification result to the control unit 321.

  The control unit 321 temporarily stores the notified verification result in the storage unit (step S203).

  Next, the control unit 321 determines whether or not the reading position information specifying the reading range is received from the inspector terminal 2 (step S204). If the reading position information has been received, that is, if the supervisor has designated the reading range of the electronic document, “Yes” is determined in step S204, and the reading position designation unit 301 designates it from the inspector terminal 2. The reading range of the electronic document is set from the position information (step S205). When there is no position information (step S204; No), step 205 is skipped and the entire electronic document is set as a reading range.

  Subsequently, the control unit 321 hands over the information specifying the electronic document and the reading range to the reading unit 302 (step S206). The reading unit 302 expands the provided electronic document as image data on a memory, recognizes characters in the reading range of the expanded image data, and outputs text data (with line feed).

  Subsequently, the reading unit 302 supplies the reading result (text data) to the date / time data candidate extraction unit 303 (step S207).

The date / time data candidate extraction unit 303 scans the supplied text data, extracts a part corresponding to the date and date / time, and supplies the extracted date / time data candidate to the difference time calculation unit 304 (step S208).
For example, the date / time data candidate extraction unit 303 extracts a character group starting with “Heisei”, “Showa”, “Western calendar”, a number string starting with “19xx”, “200 ×”, etc. It is determined whether or not it corresponds to the second, and if it corresponds, it is notified to the difference time calculation unit 304 as a candidate.

  The difference time calculation unit 304 obtains the difference between the date and time indicated by each date data candidate extracted by the date and time data candidate extraction unit 303 and the certification date and time attached to the TST, and supplies the difference to the verification result output creation unit 305 ( Step S209).

  The verification result output creation unit 305 receives the verification result of the verification unit 33, the output of the date / time data candidate extraction unit 303, and the differential time calculation unit 304, and records the electronic document, TST, and differential time records (that is, the differential time list). Including verification data is created (step S210). At this time, an NG or OK message corresponding to the difference calculated by the difference time calculation unit 304 is created and attached. For example, if the difference is 0 day or more and less than +2 days, OK, +2 days or more, or a negative value, NG.

  The control unit 321 transmits verification data to the inspector terminal 2 via the transmission unit 32 (step S211), and ends the current verification operation.

  The inspector terminal 2 receives the verification data from the time stamp information verification device 3 and displays it on the display unit.

  The auditor determines the authenticity of the contents of the electronic document with reference to the verification data displayed on the auditor terminal 2.

The operation of FIG. 4 will be described based on a specific example.
Here, the electronic document to be verified is as shown in FIG. 5A, and as shown in FIG. 5B, the date and time described in the TST is “2004.10.18.7:00: 00 ”, and the auditor does not designate the recognition range of the electronic document.

  The operation in this case will be described with reference to FIGS. 6 (a) and 6 (b). In this case, No is determined in step S204 in FIG. 4, and the reading position designating unit 301 sets the reading range as the entire document as shown in FIG. 6B. The reading unit 302 recognizes characters in the electronic document in order from the top (step 207). As a result, all the documents, that is, “XX Trading Co., Ltd. 21: 10: 57 + 09′00” ”are read.

  The date / time data candidate extraction unit 303 extracts the character strings “September 24, 2004” and “2004.10.07 21: 10: 57 + 09′00” ”estimated to correspond to the time from the above-described steps (step S40). S208).

  Next, the difference time calculation unit 304 sets the date and time data candidate “September 24, 2004” in accordance with the TST description time “2004.10.8.17:00:00”. “2004.9.24 00:00:00” is converted, and “2004.10.07 21: 10: 57 + 09′00” ”is converted into“ 2004.10.7 21:10:57 ”.

  The difference time calculation unit 304 further converts the converted date and time data “2004.9.24 00:00:00” and “2004.10.7 21:10:57” and the TST description date and time “2004.4.10.8. The difference from “17:00: 00” is obtained as +14 days and +1 day.

The verification result output creation unit 305 generates verification data as illustrated in FIG. 6A from these verification results. This verification data is displayed on the inspector terminal 2. Thus, the auditor can determine the authenticity of the document by using the difference between the date and time described in the document and the date and time described in the TST without reading the entire electronic document.
On the other hand, as shown in FIG. 7B, it is assumed that the lower end of the document shown in FIG. 5A is designated by the inspector as a reading range.
In this case, Yes is determined in step S204 of FIG. 4, and the reading position specifying unit 301 specifies the reading range as shown in FIG. 7B. The reading unit 302 recognizes characters within the designated range (step S207). As a result, “2004.10.07 21: 10: 57 + 09′00” ”is read.

  The date / time data candidate extraction unit 303 extracts a character string “2004.10.07 21: 10: 57 + 09′00” ”estimated to correspond to the date / time from among these (step S208).

  Next, the difference time calculation unit 304, since the time described in the TST is “2004.10.8.17:00:00”, the date / time data candidate “2004.10.07 21:10” : 57 + 09'00 "" is converted to "2004.10.7 21:10:57".

  The difference time calculation unit 304 further sets the difference between the converted date and time data “2004.10.7 21:10:57” and the TST description date and time “2004.10.8 17:00:00” as +1 day. Ask.

  The verification result output creation unit 305 generates verification data as illustrated in FIG. 7A from these verification results. This verification data is displayed on the inspector terminal 2. Thus, the auditor can determine the authenticity of the document by using the difference between the date and time described in the document and the date and time described in the TST without reading the entire electronic document.

  The above embodiment is an example, and the scope of application of the present invention is not limited to this. That is, various applications are possible, and all embodiments are included in the scope of the present invention.

For example, FIGS. 6 and 7 do not show the verification result in the verification unit 33 on the inspector terminal screen, but the verification result in the verification unit 33 can be displayed appropriately to assist the audit operation of the auditor. Good.
Further, only the TST that has passed the verification by the verification unit 33 may be verified by the differential time calculation unit 304 or the like.
Although OK, NG, and the like are added according to the magnitude of the date and time difference, the display color may be changed.

  The TST configuration, system configuration, operation, and the like can be arbitrarily changed as long as the same functional configuration is obtained.

  The time stamp information verification device 3 according to the above embodiment can be realized by a general-purpose computer system as well as realized by a dedicated device. In this case, it is possible to cause the general-purpose computer device to function as the time stamp information verification device 3 by installing a program for realizing each of the processes in the general-purpose computer system and executing the program in cooperation with the OS.

  The method for providing such a program is arbitrary, and may be provided via a communication medium such as the Internet as well as being provided by being stored in a recording medium such as a CD-ROM.

It is a figure which shows typically the auditor terminal, time stamp information verification apparatus, and time stamp server apparatus which concern on embodiment of this invention. It is a block diagram which shows the structure of the time stamp information verification apparatus shown in FIG. It is a figure which shows the functional structure of the time stamp information verification apparatus of FIG. It is a flowchart for demonstrating the processing operation | movement of the verification process which concerns on embodiment of this invention. It is a figure which shows the example of the electronic document of verification object, and TST. It is a figure which shows the example of the verification result and difference time list which are displayed on the display screen of an auditor terminal when an auditor does not specify reading position information of an electronic document. It is a figure which shows the example of the verification result and difference time list which are displayed on the display screen of an auditor terminal when an auditor designates reading position information of an electronic document.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 User terminal 2 Auditor terminal 3 Time stamp information verification apparatus 4 Time stamp server apparatus 21 Control apparatus 22 Communication part 31 Reception part 32 Transmission part 33 Verification part 321 Control part 323 Storage part 331 Time stamp format verification part 332 Time stamp effective Validity verification unit 333 Electronic document data and TST correspondence verification unit 34 Difference verification unit 301 Reading position designation unit 302 Reading unit 303 Date / time data candidate extraction unit 304 Difference time calculation unit 305 Verification result output creation unit

Claims (8)

A time stamp information verification support server device connected to each other by a client device and a communication network,
Receiving means for acquiring an electronic document sent from the client device and time stamp information proving the date and time when the electronic document existed;
Reading means for reading information about the date and time in the electronic document received by the receiving means;
Difference calculating means for calculating a difference between the date and time indicated by the date and time information read by the reading means and the date and time indicated by the time stamp information;
Transmitting means for transmitting difference information indicating the difference calculated by the difference calculating means to the client device;
A time stamp information verification support server device comprising:   The reading means comprises character recognition means for character recognition of the electronic document, and date / time information reading means for reading information related to date / time from among characters recognized by the character recognition means. The time stamp information verification support server device according to 1. The receiving means includes
Receiving range designation information for designating the reading range of the electronic document from the client device;
The reading unit reads information related to the date and time in the range specified by the range specifying information in the electronic document received by the receiving unit.
The time stamp information verification support server device according to claim 1 or 2, characterized in that The transmitting unit transmits an index indicating a degree of difference calculated by the difference calculating unit to the client device;
4. The time stamp information verification support server device according to claim 1, 2, or 3. Format verification means for verifying the format of the electronic document received by the reception means;
Date verification means for determining whether or not the date and time indicated by the generation date and time information added to the file name of the electronic document received by the reception means is before the date and time when the electronic document existed;
The time stamp information verification support server device according to claim 1, further comprising at least one of: The document acquisition means acquires the electronic document to be verified and the time stamp information of the electronic document,
Reading means reads information on the date and time in the acquired electronic document,
The difference calculation means calculates the difference between the date and time indicated by the read date and time information and the date and time indicated by the time stamp information,
A transmission means transmits difference information indicating the calculated difference.
A time stamp information verification support method. On the computer,
Obtain the electronic document to be verified and the time stamp information of the electronic document,
Read the date and time information in the acquired electronic document,
Calculate the difference between the date and time indicated by the read date and time information and the date and time indicated by the time stamp information,
Sending difference information indicating the calculated difference,
A computer program that executes an action.   A document acquisition means for acquiring an electronic document to be verified and time stamp information of the electronic document;
  Reading means for reading information on the date and time in the electronic document acquired by the document acquisition means;
  Difference calculating means for calculating a difference between the date and time indicated by the date and time information read by the reading means and the date and time indicated by the time stamp information;
  Transmitting means for transmitting difference information indicating the difference calculated by the difference calculating means;
  A time stamp information verification support apparatus comprising:

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