JP2020024714A - Information management method and apparatus - Google Patents

Abstract

To store hash values of time stamps in a reliable organization and to clarify association of an original file as an object of the time stamps with time stamp tokens including hash values generated by the file.SOLUTION: The present invention is directed to a method carried out by a user terminal which can be connected to a time stamp server for issuing a time stamp token including a hash value on the basis of object data requested by a user, and a storage server for issuing a unique storage ID for the issued time stamp token to store the storage ID and the time stamp token. The user terminal carries out, with respect to the object data, processing for storage request by transmitting the time stamp token issued by the time stamp server to the storage server and processing for, in response to the storage request, receiving the storage ID issued by the storage server to store the object data in data storage means in association with the storage ID.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique relating to an information management method, and is particularly suitable for managing a time stamp.

Conventionally, a time stamp is issued (issued) to an electronic file.
The time stamp includes, in addition to the date and time information at the time of issuance, a hash value calculated mainly by a predetermined hash algorithm based on a file to be stamped with the time stamp (original file). (Time stamp issuing authority). Hereinafter, in this specification, digital data of a time stamp is also referred to as time stamp data and a time stamp token (TST).
Then, the guarantee that the original file has not been falsified (original property) after the time stamp is secured by the above-described hash value. That is, by comparing the hash value at the time of issuing the time stamp with the hash value generated from the original file again at the time of verification, if the hash value has not changed, it is ensured that the contents of the original file have not changed. It was working.
As such a conventional time stamp technique, there is a technique described in Patent Document 1, and the technical content described in the conventional technique is part of the present specification.

JP 2014-42214 A JP 2012-175555 A JP 2012-028882 A

In the above-described conventional time stamp system, a hash value ensures that the original file is not falsified (originality). However, if this hash value is lost, the originality cannot be verified. There was a problem that would.
In addition, it is conceivable to back up the hash value to another server, but in this case, the association between the original file and the hash value depends on the reliability of the database that manages these data. However, there was a problem that it became very unstable.
Further, if the issued time stamp is lost, there is a problem that the fact that the original file exists at the time of issuing the time stamp (existence fact) cannot be proved.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and at least a hash value of a time stamp is stored in a trusted authority, and an original file subjected to the time stamp is generated. The purpose is to clarify the association with the generated hash value. It is another object of the present invention to store a time stamp including a hash value in a trusted organization, and to clarify the association between the time stamp target original file and the time stamp.

  In order to achieve the above object, an information management method according to one aspect of the present invention includes a time stamp device that issues a time stamp token including a hash value based on target data requested by a user, A method performed by an information management device configured to be able to connect to a storage device that stores a unique storage ID for the stamp token and to store the storage ID and the time stamp token. A process for sending a time stamp token issued by the time stamp device to the storage device for the target data and making a storage request, and receiving a storage ID issued by the storage device for the storage request. And storing the target data in a data storage unit in association with the storage ID.

  A process for requesting the time stamp device to issue a unique time stamp ID for the target data may be further performed.

  The time stamp issuing device further issues a time stamp ID for identifying the time stamp when issuing the time stamp, and transmits the time stamp ID to the storage device in accordance with the processing. The time stamp ID may be further stored in association with the storage ID.

  A process of writing information (file name) for specifying the target data in the body, attaching the target data, and generating an intermediate PDF file in which the obtained time stamp token is stored in a signature column; Describes the obtained storage ID in the text, attaches the intermediate PDF file, and stores the timestamp token generated by the timestamp device based on the intermediate PDF file in the title column in the title box. And a generating process.

  An information management device according to an aspect of the present invention includes a time stamp device that issues a time stamp token including a hash value based on target data requested by a user, and a unique time stamp token for the issued time stamp token. A device that issues a storage ID and is configured to be connectable to a storage device that stores the storage ID and the time stamp token. The device stores a time stamp token issued by the time stamp device with respect to the target data. Storage request means for transmitting a storage request to the storage device, receiving a storage ID issued by the storage device in response to the storage request, and associating the time stamp token and the target data with the storage ID And data storage means for storing

  Intermediate PDF file generating means for writing information (file name) for specifying the target data in the text, attaching the target data, and generating an intermediate PDF file in which the obtained time stamp token is stored in a signature column; The storage requesting means stores the acquired storage ID in the text, attaches the intermediate PDF file, and stores a time stamp token generated by the time stamp device based on the intermediate PDF file in a title field. And a wrapper PDF file generating means for generating a bag PDF file.

  A computer program according to one aspect of the present invention includes a time stamp device that issues a time stamp token including a hash value based on target data requested by a user, and a unique storage for the issued time stamp token. A computer program that issues an ID and causes a computer configured to be connectable to a storage device that stores the storage ID and the time stamp token to function as an information management device. Sending a timestamp token issued by the timestamp device to the storage device to issue a storage request; receiving a storage ID issued by the storage device in response to the storage request, The time stamp token and the target data in association with the ID Characterized in that to execute a process of storing in the data storage means.

  A process of writing information identifying the target data in the text, attaching the target data, and generating an intermediate PDF file storing the obtained time stamp token in a signature column; Generating a zip file PDF file containing the time stamp token generated by the time stamp device based on the intermediate PDF file in the title field with the stored storage ID described in the text, attached to the intermediate PDF file, and May be further executed.

  According to the present invention, time stamp data (time stamp token) including a hash value is stored in a trusted third party, and the association between the time stamp target original file and the time stamp data is clearly defined. Can be As a result, the existence fact proof and the originality of the original file at the time of issuing the time stamp can be more reliably secured.

FIG. 1 is a system schematic diagram of a first embodiment. 3 is a processing flow according to the first embodiment. 9 is a processing flow according to the second embodiment. FIG. 7 is a system schematic diagram of a third embodiment. 13 is a processing flow according to the third embodiment. 16 is an example of a login screen according to the fourth embodiment. 13 is an example of a registration screen according to the fourth embodiment. 13 is an example of a screen displaying a registration result according to the fourth embodiment. 16 is an example of a list display screen according to the fourth embodiment. 13 is an example of a search condition specification screen according to the fourth embodiment. 16 is an example of an individual detail screen according to the fourth embodiment. 14 is an example of an individual verification screen according to the fourth embodiment.

FIG. 1 is a diagram showing the overall configuration of the first embodiment of the present invention.
In FIG. 1, in the present embodiment, a time stamp server 1, a user terminal 2, and a storage server 3 operated by a public organization or the like are configured to be connectable via a network such as the Internet.
The time stamp server 1 performs a process of issuing time stamp data (time stamp token, TST) in response to a request from a user. The time stamp data includes data such as a hash value generated by a predetermined algorithm based on the original file, in addition to the date and time when the time stamp was issued, and a certificate (TSA certificate) representing the time stamp issuing organization. Data).
The time stamp server 1 is held by a time stamp issuing organization.

The user terminal 2 is a computer terminal that can be connected to the Internet. The user terminal 2 may be any computer terminal that can be connected to the Internet, such as a so-called personal computer terminal or PDA (Personal Digital Assistant) terminal.
The user terminal 2 realizes a data storage unit 21, a time stamp acquisition unit 22, a storage ID acquisition unit 23, and an authentication processing unit 24 by the CPU executing a computer program stored in a storage unit such as a hard disk. can do.
The data storage unit 21 is a storage unit that stores an original file, time stamp data, and, if necessary, certificate data and a storage ID issued by the storage server 3.
The time stamp acquisition unit 22 requests the time stamp server 1 to acquire time stamp data for the original file. The time stamp acquisition process is performed by the time stamp acquisition unit 22 generating a hash value from the original file based on a predetermined hash algorithm, and transmitting the generated hash value to the time stamp server 1. Can be. Alternatively, the time stamp acquisition unit 22 may transmit the original file itself to the time stamp server 1 and generate a hash value on the time stamp server 1 side.
The storage ID obtaining unit 23 obtains the storage ID from the storage server 3 by transmitting at least the hash value data of the time stamp to the storage server 3 when the time stamp is obtained, and stores the obtained storage ID in the data. The storage unit 21 performs a process of storing the original file in association with the original file. The data to be transmitted to the storage server 3 may be only the hash value, or the time stamp data may be transmitted.
The authentication processing unit 24 performs a process of requesting the storage server 3 to authenticate whether the hash value currently held by the user matches the hash value stored in the storage server 3.

The storage server 3 is a server operated by a public organization.
This storage server 3 is for storing the hash value of the time stamp.
The storage server 3 has a management database 31, a storage ID issuing unit 32, and an authentication processing unit 33.
The management database 31 is a storage unit that associates and stores a hash value received from a user and a storage ID issued to the user when the hash value is received from the user.
The storage ID issuing unit 32 issues a unique storage ID associated with the hash value to the user based on a hash value storage request from the user.
The authentication processing unit 33 authenticates whether the hash value currently held by the user matches the hash value stored in the storage server 3 in response to an authentication request from the user who has deposited the hash value.

Next, a flow of processing of the above-described embodiment will be described.
In FIG. 2, when the user first obtains the time stamp of the original file, the time stamp obtaining unit 22 of the user terminal 2 transmits a time stamp obtaining request to the time stamp server 1 (S1).
In response to the time stamp acquisition request, the time stamp acquisition unit 22 may generate a hash value from the original file based on a predetermined hash algorithm and transmit the hash value. When the hash value is generated on the time stamp server 1 side, the original file itself may be transmitted to the time stamp server 1 at the time of the time stamp acquisition request.

  When a time stamp issuance request is made, the time stamp server 1 issues time stamp data and transmits it to the user terminal 2 (S2).

When the time stamp is issued, the storage ID acquisition unit 23 of the user terminal 2 requests the storage server 3 to issue a storage ID (S3).
At the time of this issuance request, the storage ID acquisition unit 23 transmits at least the hash value of the time stamp data to the storage server 3. At the time of this issuance request, not only the hash value but also time stamp data may be transmitted. Further, user information and the like may be transmitted as needed.

  When a request for issuing a storage ID is made, the storage ID issuing unit 32 of the storage server 3 issues a unique storage ID in response to the request, and manages data such as a hash value received in association with the storage ID. While registering in the database 31, the issued storage ID is transmitted to the user terminal 2 (S4).

The storage ID acquisition unit 23 of the user terminal 2 stores the acquired storage ID in the data storage unit 21 in association with the time stamp data including the hash value (S5). At this time, user information such as the original file and the registrant name may be stored in association with the original file.
Thus, the issuance of the storage ID and the association at the user terminal 2 are completed.

Further, when performing authentication processing on the storage server 3 at a later date, the authentication processing unit 24 of the user terminal 2 transmits an authentication request to the storage server 3 (S11).
This authentication request is performed by transmitting at least a storage ID and a hash value to be authenticated. Further, time stamp data and user information for specifying the user may be transmitted as necessary.

  When an authentication request is made, the authentication processing unit 33 of the storage server 3 searches the management database 31 based on the storage ID, specifies a registered hash value, and the like, and determines the hash value and the hash value of the authentication request. The value is compared with the value, the authentication result is transmitted to the user terminal 2 (S12), and the process ends.

  As described above, according to the above-described embodiment, the user not only stores the hash value or the like issued by the time stamp server 1 by himself, but also registers the hash value in the storage server 3 operated by a public organization and performs authentication. Since the hash value can be stored by an objective third party, the proof power can be improved.

A second embodiment will be described with reference to FIG.
In the embodiment shown in FIG. 3, when a time stamp is issued, the time stamp server 1 issues a unique time stamp ID (TSID) (S22), and the time stamp ID (TSID) is stored in the time stamp data. This is an example in which the ID and the ID are stored in association with the data storage unit 21 (S25). Since other configurations and processes are the same as those in the above-described embodiment, the description will be omitted.

  As described above, according to the second embodiment, by linking and storing the TSID issued by the time stamp server 1, it is possible to certify a series of flows from issuance to storage of the time stamp in association with each other.

  In the second embodiment, the time stamp ID (TSID) may be transmitted to the storage server 3 and registered in the storage server 3 in association with the storage ID.

Next, a third embodiment will be described with reference to FIGS.
In the third embodiment, an original file, time stamp data, and the like are associated by a PDF file.
In this embodiment, first, the time stamp obtaining unit 22 writes “original file name” in the text of the PDF before obtaining the time stamp (S101).
In this state, the time stamp acquisition unit 22 attaches the original file to the PDF file whose original file name is described in the text to form one PDF file (S102).
In this state, a hash value is generated based on the PDF file (S103). As a result, a hash value is generated based on the content described in the body of the PDF file and the attached original data, so that changing any of these values will change the hash value. In other words, thereby, the content described in the body of the PDF file and the attached original data are linked.
Based on the above-mentioned hash value, the time stamp server 1 is requested to issue a time stamp (S104). Then, the issued time stamp data is embedded in the signature area of the PDF (S105). Note that the signature area is an area irrelevant to the calculation of the hash value (not a basis), and can be added later. As a result, a PDF file (hereinafter, referred to as “intermediate PDF file”) in which the original file, the body in which the file name is described, and the time stamp data are integrated is generated.

In this state, the processes in S3 and S4 described above are performed, the hash value is transmitted to the storage server 3, and the storage ID is obtained from the storage server 3 (S106).
After obtaining the storage ID, the storage ID obtaining unit 23 writes the obtained storage ID in the text of a new PDF file (envelope PDF file) (S107).
Then, the previously generated intermediate PDF file is attached to the wrapper PDF file (S108).
Again, a hash value of the PDF file is generated, transmitted to the time stamp server, and time stamp data is acquired (S109), and embedded in the signature area of the PDF file (S110).
Thus, the intermediate PDF file is managed in association with the storage ID described in the text.

As described above, according to the third embodiment, all necessary data can be stored in association with the PDF file, so that the management becomes very simple.
The data of the generated zipper PDF file may be managed in a database.

  In the above-described third embodiment, the intermediate PDF file and the wrapper PDF file are not generated by the user terminal 2 but are generated by the time stamp server 1 or a separately provided server (for example, a Web server having an ASP function). ) May be generated.

In any of the above embodiments, the storage server 3 may store not only the hash value but also the time stamp data itself. In addition, user information and the like may be stored together.
At the same time, the registered time stamp data, storage ID, original file, and the like can be stored in the user terminal 2 in association with each other, and their time limits can be managed.

Next, a fourth embodiment will be described mainly with reference to FIGS.
The fourth embodiment is an example in which the present invention is implemented as a time stamp management system. Basically, it is the same as the first to third embodiments, so illustration other than the screen example is omitted. However, between the time stamp server 1 and the storage server 3 and the user terminal 2 directly used by the user, An ASP server 2A is separately provided using a Web service, and has a configuration including functions equivalent to those of the user terminal 2 in the first to third embodiments (not shown). Separating the terminal from the ASP and leaving the main information processing function to the ASP facilitates system management accompanying the addition of functions.
In this embodiment, the user terminal 2 transmits not only the hash value but also the TST including the hash value to the storage server 3 via the ASP server 2A. That is, in the present embodiment, the data storage unit 21 is a storage unit that stores an original file, a time stamp token (TST), various certificate data as needed, and at least a storage ID issued by the storage server 3. is there.
The time stamp acquisition unit 22 requests the time stamp server 1 to acquire a time stamp token (TST) for the original file. The time stamp acquisition process is performed by the time stamp acquisition unit 22 generating a hash value from the original file based on a predetermined hash algorithm, and transmitting the generated hash value to the time stamp server 1. Can be. As a result, the time stamp can be obtained safely without leaking the original file itself.
The storage ID obtaining unit 23 obtains at least the storage ID from the storage server 3 by transmitting the TST to the storage server 3 when the TST can be obtained, and stores the obtained storage ID with the original file and the TST. A process of storing the data in the data storage unit 21 in association therewith is performed.
The authentication processing unit 24 requests the storage server 3 to authenticate whether the TST currently held in the user storage unit 21 in association with the target file matches the TST stored in the storage server 3. Perform processing.

FIG. 6 is a login screen for a user to log in to the time stamp management system of the present embodiment. FIG. 7 is a registration screen for registering a target file in the present system, and FIG. 8 is a screen for displaying a registration result. FIG. 9 is a list display screen for displaying a list of registered files. FIG. 10 is a search condition designation screen, FIG. 11 is an individual detail screen, and FIG. 12 is an individual verification screen.
As shown in FIG. 6, the user logs in to the system by inputting a user ID and a password and pressing (clicking) a login button. When the user logs in, the user can register target files to be managed, such as an original file for which a time stamp is to be pressed and a time stamp certificate file for which a time stamp has been stamped.

As shown in FIG. 7, the user selects the type of the target file to be registered from the “type of input information” field 71 using a pull-down menu or the like, and inputs the file name into the “input file” field 72. At this time, as shown in FIG. 7, a reference button may be pressed. If there is a certificate including the storage ID acquired from the storage server 3 (called a storage certificate) in the “Storage Certificate” column 73, the file name of the storage certificate is input. This allows the system to manage the storage certificate in association with the target file. The storage certificate includes a time stamp token stored in the storage server 3 in addition to the storage ID, and may include a storage date and time. Instead of the storage certificate column, only the storage ID may be registered. In the remarks column 74, remarks are input as necessary. In the search information column 75, information serving as a key at the time of a search is appropriately input.
When the registration button 76 in FIG. 7 is pressed, the time stamp management system performs a registration process corresponding to the type of the input target file, records it in the data storage unit, and registers the registration result as shown in FIG. Is displayed on the screen. The registration number shown in FIG. 8 is uniquely assigned when the target data is registered in the present system, and is a number for specifying and managing the target data. The storage ID issued when the storage request is issued to the storage server 3 may be displayed together with the registration number on the registration result display screen shown in FIG.

Here, the “type of target file” is, for example, an original file for which a new time stamp is to be pressed, a time stamp certificate file (a PDF including the original file and a time stamp token), which has been described in the third embodiment. For example, “intermediate PDF file” and “zipper PDF file”.
“Registration processing corresponding to the type of input target file” will be described for each type of target data.
If the target data is an original file for which a new time stamp is to be added, the registration number of the original file is set to “intermediate PDF file” as in the third embodiment, and the TST at this time is stored in the storage server 3. And stores at least the storage ID in the data storage unit in association with the original file and manages the received storage ID. If necessary, a “wrapper PDF file” is created as in the third embodiment.
When the target data is a time stamp certificate file, a TST is taken out of the file, the TST is deposited in the storage server 3, at least a storage ID is received, and the received storage ID is associated with the time stamp certificate file. Stored in the data storage unit for management. Similarly, an “intermediate PDF file” and a “zipper PDF file” may be created. When the target data is the “intermediate PDF file” described in the third embodiment, the TST extracted from the file is deposited in the storage server 3, at least the storage ID is received, and the received storage ID is used as the time stamp certificate. The data is stored in the data storage unit in association with the file and managed. Similarly, a “wrapper PDF file” may be created.
As a result of the registration, for example, when files to be managed such as “intermediate PDF file” and “zipper PDF file” are created on the ASP server 2A, the user clicks the download button as shown in FIG. By pressing, these files can be downloaded from the server to the user terminal 2.

FIG. 9 is a list display screen for displaying a list of registered files. As shown in FIG. 9, a list of files registered in the system is displayed on the list display screen. Alternatively, a list of files matching the search conditions specified on the search condition specification screen shown in FIG. 10 is displayed on the list display screen. Search conditions can be specified in the list display screen.
When the search button in FIG. 9 is clicked, a search condition designation screen (FIG. 10) is displayed. When the detail button (D button) is clicked while the check box of the individual file is checked, an individual detail screen (FIG. 11) is displayed. When the verification button (V button) is clicked while the check box of the individual file is checked, an individual verification screen (FIG. 12) is displayed. When the collective verification button is clicked, a collective verification screen (not shown) is displayed.

  On the individual detail screen, as shown in FIG. 11, information (registration date and time, file name, remarks, search information) registered for the target file and the contents of the time stamp token (TST) are displayed. When the verification button is clicked, the authentication processing unit 24 acquires the TST (including the hash value) stored in the storage server 3 using the storage ID associated with the target file as a key, and Verification is performed by comparing with the TST stored in association with.

  As described above, according to the present embodiment, even when a new time stamp is applied to the original data, a time stamp certificate file for which a time stamp has been already applied can be treated as target data. it can. Then, the TST including the hash value is registered in the storage server 3, and the storage ID for extracting the registered TST can be managed in association with the target data. That is, the time stamp token including the hash value can be stored in a trusted third party, and the association between the original file subjected to the time stamp and the time stamp data can be clarified. As a result, the existence fact proof and originality guarantee at the time of issuing the time stamp of the original file can be further ensured.

  The above embodiments can be applied in combination. Further, the computer program for the user terminal of each of the above-described embodiments or the computer program may be stored in a recording medium (CDROM or the like) and distributed.

1 time stamp server 2 user system 3 storage server 21 data storage unit 22 time stamp obtaining unit 23 storage ID obtaining unit 24 authentication processing unit 31 management database 32 storage ID issuing unit 33 authentication processing unit

In order to achieve the above object, an information management method according to one aspect of the present invention provides a method for generating time stamp data including a hash value calculated from a target data by a predetermined hash algorithm based on the target data requested by a user. lines and time-stamping device for issuing issues a unique storage ID to the issued time stamp data, this storage ID and time stamp data and connectable to information management apparatus and the storage device stores a dividing method, the information management apparatus, and a process for storing requests time stamp data issued by the timestamp device relative to the target data was sent to the storage device, to said storage request receiving a storage ID of the storage device is issued, in association with the storage ID received, especially the target data The information and the time stamp data and having and a process of storing in the storage means of the information management apparatus.

A process of writing information (file name) for specifying the target data in the body, attaching the target data, and generating an intermediate PDF file storing the obtained time stamp data in a signature column; Generating an envelope PDF file storing the time stamp data generated by the time stamp apparatus based on the intermediate PDF file in the signature column with the ID described in the text and attaching the intermediate PDF file. May have.

An information management device according to one aspect of the present invention is a time stamp device that issues time stamp data including a hash value calculated from the target data by a predetermined hash algorithm based on target data requested by a user, issues a unique storage ID to the issued time stamp data, a connectable to the apparatus configured as storage device stores and the store ID and time stamp data, the relative said target data Storage request means for transmitting a timestamp data issued by a timestamp device to the storage device to make a storage request, receiving a storage ID issued by the storage device in response to the storage request, and receiving the received storage ID in association, memory means for storing the information and the time stamp data identifying the target data, Characterized in that it has.

Intermediate PDF file generating means for writing information (file name) for specifying the target data in the text, attaching the target data, and generating an intermediate PDF file in which the obtained time stamp data is stored in a signature column; The acquired storage ID is described in the text, the intermediate PDF file is attached, and a signature box is used to generate a zipper PDF file storing the time stamp data generated by the time stamp device based on the intermediate PDF file. Wrapper PDF file generating means.

A computer program according to one aspect of the present invention includes a time stamp device that issues time stamp data including a hash value calculated from a target data by a predetermined hash algorithm based on the target data requested by a user; issues a unique storage ID to the issued time stamp data, a computer program to function the storage ID and time stamp data and computer configured to be connectable to a storage device that stores the information management apparatus Sending a timestamp data issued by the timestamp device to the target data to the storage device to the storage device to make a storage request, the storage device responding to the storage request, to receive the issued store ID, the store ID received Put communication, characterized in that to execute a process of storing the information and the time stamp data identifying the target data.

A process of writing information identifying the target data in the text, attaching the target data, and generating an intermediate PDF file storing the obtained time stamp data in a signature column; and A process of writing a storage ID in the text, attaching the intermediate PDF file, and generating a zipper PDF file that stores the time stamp data generated by the time stamp device based on the intermediate PDF file in the signature column, May be further executed.

Claims (8)

A time stamp device that issues a time stamp token including a hash value calculated from the target data by a predetermined hash algorithm based on the target data requested by the user, and a unique time stamp token for the issued time stamp token. A method performed by an information management device configured to connect to a storage device that issues a storage ID and stores the storage ID and the time stamp token,
A process in which the information management device sends a time stamp token issued by the time stamp device to the storage device and issues a storage request to the target data;
A process of receiving a storage ID issued by the storage device in response to the storage request, and storing the target data in a data storage unit in association with the storage ID;
An information management method comprising: Further performing a process of requesting the time stamp device to issue a unique time stamp ID for the target data;
The information management method according to claim 1. When the time stamp device issues time stamp data, the time stamp device further issues a time stamp ID for identifying the time stamp data, and transmits the time stamp ID to the storage device.
The data storage means further stores the time stamp ID in association with the storage ID.
The information management method according to claim 1. A process of writing information identifying the target data in the text, attaching the target data, and generating an intermediate PDF file storing the obtained time stamp token in a signature column;
The storage requesting means stores the acquired storage ID in the text, attaches the intermediate PDF file, and stores a time stamp token generated by the time stamp device based on the intermediate PDF file in a title field. A process of generating a bag PDF file;
2. The information management method according to claim 1, further comprising: A time stamp device that issues a time stamp token including a hash value calculated from the target data by a predetermined hash algorithm based on the target data requested by the user, and a unique time stamp token for the issued time stamp token. A device that issues a storage ID and is configured to be connectable to a storage device that stores the storage ID and the time stamp token,
Storage request means for transmitting a time stamp token issued by the time stamp device to the storage device and requesting a storage for the target data,
Data storage means for receiving the storage ID issued by the storage device in response to the storage request, and storing the time stamp token and the target data in association with the storage ID;
An information management device, comprising: Intermediate PDF file generating means for writing information (file name) for specifying the target data in the text, attaching the target data, and generating an intermediate PDF file in which the obtained time stamp token is stored in a signature column;
The storage requesting means stores the acquired storage ID in the text, attaches the intermediate PDF file, and stores a time stamp token generated by the time stamp device based on the intermediate PDF file in a title field. A wrapper PDF file generating means for generating a bag PDF file;
The information management device according to claim 5, further comprising: A time stamp device that issues a time stamp token including a hash value calculated from the target data by a predetermined hash algorithm based on the target data requested by the user, and a unique time stamp token for the issued time stamp token. A computer program that issues a storage ID and causes a computer configured to be connectable to a storage device that stores the storage ID and the time stamp token to function as an information management device,
For the above computer,
A process of transmitting a time stamp token issued by the time stamp device to the storage device and performing a storage request for the target data;
In response to the storage request, receiving a storage ID issued by the storage device, storing the time stamp token and the target data in a data storage unit in association with the storage ID,
A computer program that executes A process of writing information identifying the target data in the text, attaching the target data, and generating an intermediate PDF file storing the obtained time stamp token in a signature column;
The storage requesting means stores the acquired storage ID in the text, attaches the intermediate PDF file, and stores a time stamp token generated by the time stamp device based on the intermediate PDF file in a title field. A process of generating a bag PDF file;
Computer program to further execute.

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