How to issue a timestamp
A local timestamp device in offline environments issues and verifies timestamps using an official Internet-based authority, ensuring reliable timestamping by integrating local and official tokens in a ledger for verification.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NEC SOLUTION INNOVATORS LTD
- Filing Date
- 2021-10-27
- Publication Date
- 2026-06-23
Smart Images
Figure 0007878676000001 
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Figure 0007878676000003
Abstract
Description
Technical Field
[0001] The present invention relates to a timestamp issuing method, a local timestamp issuing device, and a program.
Background Art
[0002] For electronic data such as documents, images, videos, and voices, in order to prove that it existed at a specific time and has not been tampered with after the specific time, a timestamp is issued (see Patent Document 1). The timestamp is issued by a formal time certification authority designated by a country or the like by electronically signing the hash value of the electronic data by associating time information.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Here, the timestamp issuing server of the above-mentioned formal time certification authority is usually installed on the Internet. Therefore, a user who requests a timestamp needs to be in an environment connected to the Internet. However, when the user who requests a timestamp is an organization that has taken measures to prevent information leakage, such as a public institution or a company, the information processing device of such an organization is basically in an offline environment. Then, in such an organization, there arises a problem that a timestamp cannot be requested from a formal time certification authority on the Internet.
[0005] On the other hand, in organizations operating in an offline environment as described above, it is conceivable to set up a local time certificate authority (Certificate of Authenticity) within the organization's local environment and have that local Certificate of Authenticity issue timestamps. However, in this case, since the local Certificate of Authenticity is not an official Certificate of Authenticity, the reliability of the timestamps is questionable.
[0006] Therefore, the object of the present invention is to provide a timestamp issuance method that can solve the above-mentioned problem of not being able to issue reliable timestamps in an offline environment. [Means for solving the problem]
[0007] A timestamp issuance method, which is one embodiment of the present invention, A method for issuing timestamps using a local timestamp issuing device installed in an offline environment, In response to a request for a timestamp for electronic data from a predetermined information processing device installed in the same local environment as the local timestamp issuing device, a timestamp token is issued for said electronic data. At a predetermined time, connect to a specific timestamp issuing device located on the internet and request a timestamp from that specific timestamp issuing device for the ledger data, including the timestamp token issued for the electronic data. A timestamp token issued for the ledger data from the specified timestamp issuing device is obtained. This is the structure it takes.
[0008] Furthermore, a local time stamp issuing device, which is one embodiment of the present invention, A local timestamp issuing device installed in an offline environment, A timestamp issuing unit that issues a timestamp token for electronic data in response to a request for a timestamp for electronic data from a predetermined information processing device installed in the same local environment as the local timestamp issuing device, A ledger timestamp request unit connects to a specific timestamp issuing device located on the internet at a predetermined timing and requests a timestamp from the said specific timestamp issuing device for the ledger data, which includes the timestamp token issued for the electronic data. A ledger timestamp acquisition unit that acquires a timestamp token issued for the ledger data from the specified timestamp issuing device, Equipped with, This is the structure it takes.
[0009] Furthermore, a program, which is one embodiment of the present invention, A local timestamp issuing device installed in an offline environment, In response to a request for a timestamp for electronic data from a predetermined information processing device installed in the same local environment as the local timestamp issuing device, a timestamp token is issued for said electronic data. At a predetermined time, connect to a specific timestamp issuing device located on the internet and request a timestamp from that specific timestamp issuing device for the ledger data, including the timestamp token issued for the electronic data. A timestamp token issued for the ledger data from the specified timestamp issuing device is obtained. To execute the process This is the structure it takes. [Effects of the Invention]
[0010] With the configuration described above, the present invention can issue highly reliable timestamps even in an offline environment. [Brief explanation of the drawing]
[0011] [Figure 1] This is a diagram showing the overall configuration of the timestamp issuance system in Embodiment 1 of the present invention. [Figure 2] This is a block diagram showing the configuration of the local time certification authority server disclosed in FIG. 1. [Figure 3] This is a diagram showing an example of the data structure of the timestamp ledger stored in the local time certification authority server disclosed in FIG. 1. [Figure 4] This is a diagram showing the operation of the timestamp issuance process by the timestamp issuance system disclosed in FIG. 1. [Figure 5] This is a flowchart showing the operation of the local time certification authority server disclosed in FIG. 1. [Figure 6] This is a diagram showing a modified example of the data structure of the timestamp ledger stored in the local time certification authority server disclosed in FIG. 1. [Figure 7] This is a block diagram showing the hardware configuration of the local timestamp issuance device in Embodiment 2 of the present invention. [Figure 8] This is a block diagram showing the configuration of the local timestamp issuance device in Embodiment 2 of the present invention. [Figure 9] This is a flowchart showing the operation of the local timestamp issuance device in Embodiment 2 of the present invention.
Mode for Carrying Out the Invention
[0012] <Embodiment 1> The first embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIGS. 1 to 3 are diagrams for explaining the configuration of the timestamp issuance system, and FIGS. 4 to 5 are diagrams for explaining the processing operations of the timestamp issuance system. FIG. 6 is a diagram for explaining a modified example of the timestamp issuance system.
[0013] [Configuration] The time stamp issuance system in the present invention is a system for issuing time stamps to prove that electronic data such as documents, images, videos, and audio existed at a specific time and has not been tampered with since a specific time. In particular, the present invention is configured to issue highly reliable time stamps in an offline environment that is not connected to the external internet.
[0014] As shown in Figure 1, the time stamp issuance system in this embodiment comprises a local time authentication authority server 10 and a user terminal 20, both located within a local network n. For example, the local network n is an intranet of a specific organization, such as a public institution or a company, that has implemented measures to prevent information leakage, and is basically an offline environment not connected to the external internet N.
[0015] The user terminal 20 is a predetermined information processing device operated by user U, such as an employee of a specific organization. The local time authentication authority server 10 is a server device operated by a specific organization, and as will be described later, it is configured to receive requests for timestamps for electronic data such as documents created by user U from the user terminal 20 and issue timestamps, and functions as a local timestamp issuing device that issues timestamps in a local environment.
[0016] Furthermore, the local time certification authority server 10 can only connect to the external internet N at pre-configured times, for example, at times determined each day. The external internet N has an official time certification authority server 30 operated by an official time certification authority designated by a country or other official body. The official time certification authority server 30 functions as a time stamp issuing device configured to issue time stamps in response to requests for time stamps on electronic data from pre-registered organizations or users. The local time certification authority server 10 can only access the official time certification authority server 30 when it is able to connect to the external internet N. The configuration of the local time certification authority server 10 will be described in detail below.
[0017] The local time authentication authority server 10 is composed of one or more information processing units, each equipped with a computing unit and a storage device. As shown in Figure 2, the local time authentication authority server 10 includes a timestamp issuing unit 11, a ledger timestamp request unit 12, a ledger timestamp acquisition unit 13, and a verification unit 14. The functions of the timestamp issuing unit 11, the ledger timestamp request unit 12, the ledger timestamp acquisition unit 13, and the verification unit 14 can be realized by the computing unit executing a program for realizing each function stored in the storage device. The local time authentication authority server 10 also includes a ledger storage unit 16. The ledger storage unit 16 is composed of a storage device. The following describes each configuration in detail.
[0018] When the timestamp issuing unit 11 receives a request for a timestamp for electronic data from the user terminal 20, it issues a timestamp token for the electronic data. Specifically, the timestamp issuing unit 11 issues a timestamp token that has time information added to the hash value of the electronic data for which a timestamp has been requested and has been digitally signed. At this time, the timestamp issuing unit 11 may send the issued timestamp token to the user terminal 20, or it may send the timestamp token to the user terminal 20 after verifying the timestamp ledger containing the timestamp token, as will be described later.
[0019] Then, upon issuing a timestamp token, the timestamp issuing unit 11 stores a record consisting of a combination of the hash value of the electronic data, time information, and the timestamp token in the timestamp ledger, as shown in Figure 3, and stores it in the ledger storage unit 16. At this time, the timestamp issuing unit 11 stores information about one timestamp per record in the timestamp ledger, but the timestamp ledger may store multiple records, that is, records consisting of combinations of hash values, time information, and timestamp tokens corresponding to multiple electronic data.
[0020] The ledger timestamp request unit 12 connects to the official time certification authority server 30 (a specific timestamp issuing device) located on the external internet N via the external network N at a predetermined timing. The ledger timestamp request unit 12 then requests a timestamp from the official time certification authority server 30 for the timestamp ledger (ledger data) stored in the ledger storage unit 16. In other words, the local time certification authority server 10 is normally offline, but only at a predetermined timing it connects to the external internet N and requests a timestamp for the timestamp ledger from the official time certification authority server 30. For example, the timing at which the local time certification authority server 10 connects to the external internet N is set to a specific time in the middle of the night, and at that specific time every day, batch processing is started and a timestamp request for the timestamp ledger is made. Note that the predetermined timing described above can be any timing. For example, the predetermined timing can be a specific time every day, or a periodic timing such as every certain amount of time has passed, or it can be the timing when a predetermined event occurs.
[0021] In this case, if the timestamp ledger contains multiple records, the ledger timestamp request unit 12 requests a timestamp for all of the included records together. In other words, the ledger timestamp request unit 12 requests a timestamp for the timestamp ledger that includes all records stored since the last timestamp request. For this reason, if the ledger timestamp request unit 12 is configured to connect to the official time certification authority server 30 located on the external internet N at a pre-set timing as described above, it is configured to request a timestamp from the official time certification authority server 30 for the timestamp ledger that includes all records issued and stored between the connection timing. For example, if the ledger timestamp request unit 12 is configured to start batch processing every day, it requests a timestamp for the timestamp ledger that includes all records stored before the batch processing was started on that day.
[0022] When the local time certification authority server 10 requests a timestamp for the timestamp ledger from the official time certification authority server 30, the ledger timestamp acquisition unit 13 obtains a timestamp token (ledger timestamp token) for the timestamp ledger issued by the official time certification authority server 30, as described later. Accordingly, when the ledger timestamp request unit 12 requests a new timestamp from the official time certification authority server 30, as described above, it includes the ledger timestamp token previously obtained from the official time certification authority server 30 in the new timestamp ledger for which a timestamp is to be requested, and requests a timestamp for that new timestamp ledger. In particular, the ledger timestamp request unit 12 includes the ledger timestamp token obtained from the official time certification authority server 30 in the most recent past, i.e., the previous timestamp request, in the new timestamp ledger and requests a timestamp. However, the ledger timestamp request unit 12 may include multiple past ledger timestamp tokens in the new timestamp ledger and request a timestamp, or it may request a timestamp without including past ledger timestamp tokens. Furthermore, when the ledger timestamp request unit 12 requests a timestamp from the timestamp ledger, it may send the timestamp ledger and the ledger timestamp token to the official time certification authority server 30, or it may send only the hash values of the timestamp ledger and the ledger timestamp token to the official time certification authority server 30.
[0023] The ledger timestamp acquisition unit 13 acquires a ledger timestamp token, which is a timestamp token for a timestamp ledger issued by the official time certification authority server 30 in response to a timestamp request by the ledger timestamp request unit 12, and stores it in the ledger storage unit 16. The official time certification authority server 30 issues a ledger timestamp token by adding time information to the hash value of the timestamp ledger for which a timestamp has been requested (including past ledger timestamp tokens in some cases) and digitally signing it. The ledger timestamp token stored in the ledger storage unit 16 of the local time certification authority server 10 is read by the ledger timestamp request unit 12 as described above, included in a new timestamp ledger, and a timestamp request is made to the official time certification authority server 30.
[0024] The verification unit 14 works in cooperation with the user terminal 20 to verify the electronic data for which a timestamp has been requested from the user terminal 20. Specifically, the verification unit 14 verifies the timestamp ledger using a ledger timestamp token issued by the official time certification authority server 30. For example, the verification unit 14 decrypts the ledger timestamp token obtained from the official time certification authority server 30 using the public key of the official time certification authority server 30 and verifies whether the hash value of the timestamp ledger stored in the ledger storage unit 16 matches the hash value contained in the ledger timestamp token. If the hash values match, it is proven that the timestamp ledger stored in the ledger storage unit 16 existed at the time of the time information contained in the ledger timestamp token and has not been tampered with since that time. Therefore, it is also proven that the timestamp token for the electronic data contained in the timestamp ledger exists at the time of the time information contained in the ledger timestamp token and has not been tampered with since that time. Furthermore, if the ledger timestamp includes past ledger timestamp tokens, it will be proven that those past ledger timestamp tokens existed at the time of the time information and have not been tampered with since that time.
[0025] The verification unit 14 then sends the timestamp token included in the timestamp ledger to the user terminal 20 as verified. This allows the user terminal 20 to verify the electronic data using the timestamp token, which was issued by the local time certification authority server 10 and verified by the timestamp of the official time certification authority server 30. Specifically, the user terminal 20 decrypts the timestamp token using the public key of the local time certification authority server 10 and verifies whether the hash value of the target electronic data matches the hash value included in the timestamp token. If the hash values match, the local time certification authority server 10 has proven that the electronic data stored in the user terminal 20 existed at the time of the time information included in the timestamp token and has not been tampered with since that time. Furthermore, as mentioned above, this timestamp token has been proven to exist at the time the timestamp was issued by the official time certification authority server 30 and has not been tampered with since that time, so the electronic data is similarly proven to exist at that time and has not been tampered with since that time.
[0026] Furthermore, the verification unit 14 may certify the timestamp token of electronic data when a user terminal 20 requests verification of such electronic data. In other words, the verification unit 14 may verify the timestamp ledger containing the timestamp token of the electronic data requested for verification by the user terminal 20 using the ledger timestamp token, and transmit the result to the user terminal 20.
[0027] [Operation] Next, the operation of the timestamp issuance system described above, in particular the operation of the local time certification authority server 10, that is, the operation of the local timestamp issuance method, will be explained mainly with reference to Figures 4 and 5. The local time certification authority server 10 is basically in an offline environment not connected to the external internet, and is connected to the user terminal 20 within the local network n.
[0028] When the local time authentication authority server 10 receives a request for a timestamp for electronic data from the user terminal 20 in an offline environment (code A1 in Figure 4, Yes in step S1 in Figure 5), it issues a timestamp token for the electronic data (code A2 in Figure 4, step S2 in Figure 5). The local time authentication authority server 10 may send the timestamp token to the user terminal 20 at this point, or it may later obtain a ledger timestamp token for the timestamp ledger containing the timestamp token from the official time authentication authority server 30 and then send the timestamp token to the user terminal 20.
[0029] When a timestamp token is issued, the local time authentication server 10 stores a record consisting of a combination of the hash value of the electronic data, time information, and the timestamp token, which is related to the timestamp token, in the timestamp ledger, as shown in Figure 3, and stores it in the ledger storage unit 16. The local time authentication server 10 then issues timestamps for electronic data in response to requests from the user terminal 20 (steps S1 and S2 in Figure 5) until a pre-set timing, for example, the timing of a batch processing that occurs once a day (No in step S4 in Figure 5), and stores a record consisting of information related to the timestamp in the timestamp ledger (step S3 in Figure 5).
[0030] When the local time authentication authority server 10 reaches a pre-configured timing, for example, the timing of a batch process that occurs once a day (Yes in step S4 of Figure 5), it becomes possible to connect to the official time authentication authority server 30, which is located on the external internet N, via the external network N, from the offline environment. The local time authentication authority server 10 then requests a timestamp from the official time authentication authority server 30 for the timestamp ledger stored in the ledger storage unit 16 (code A3 in Figure 4, step S5 in Figure 5). At this time, the local time authentication authority server 10 includes the ledger timestamp token previously obtained from the official time authentication authority server 30 in the new timestamp ledger for which it is requesting a timestamp, and requests a timestamp for that new timestamp ledger. In particular, the local time authentication authority server 10 includes the ledger timestamp token obtained from the official time authentication authority server 30 when requesting the most recent timestamp, i.e., the previous timestamp, in the new timestamp ledger and requests a timestamp.
[0031] Subsequently, the local time certification authority server 10 obtains a ledger timestamp token, which is a timestamp token for the timestamp ledger issued by the official time certification authority server 30 in response to a timestamp request, and stores it in the ledger storage unit 16 (symbol A4 in Figure 4, step S6 in Figure 5). After obtaining the ledger timestamp token from the official time certification authority server 30, the local time certification authority server 10 goes offline again.
[0032] The ledger timestamp token stored in the ledger storage unit 16 of the local time authentication authority server 10 is then used to verify the electronic data held by the user terminal 20 (indicated by A5 in Figure 4). For example, verification of the electronic data held by the user terminal 20 is performed as follows: First, the local time authentication authority server 10 decrypts the ledger timestamp token issued by the official time authentication authority server 30 using the public key of the official time authentication authority server 30, and checks whether the hash value of the timestamp ledger stored in the ledger storage unit 16 matches the hash value contained in the ledger timestamp token. If the hash values match, it is proven that the timestamp ledger stored in the ledger storage unit 16 existed at the time of the time information contained in the ledger timestamp token and has not been tampered with since that time. Therefore, it is also proven that the timestamp token for the electronic data contained in the timestamp ledger existed at the time timestamped by the official time authentication authority server 30 and has not been tampered with since that time.
[0033] Then, by using the verified timestamp token contained in this timestamp ledger, the user terminal 20 can verify the electronic data, proving that such electronic data existed at the time the official time certification authority server 30 issued the ledger timestamp token and has not been tampered with since that time. The verification of the electronic data by the user terminal 20 is performed by decrypting the timestamp token using the public key of the local time certification authority server 10 and checking whether the hash value of the target electronic data matches the hash value contained in the timestamp token.
[0034] As described above, according to this embodiment, even when using a local time authentication authority server 10 in an offline environment, it is possible to prove that the electronic data existed at the time of the timestamp and has not been tampered with since that time by having the official time authentication authority server 30 issue a timestamp for the timestamp ledger containing the timestamp token of the electronic data to be verified. As a result, highly reliable timestamps can be issued even in an offline environment.
[0035] Furthermore, if the timestamping process includes the ledger timestamp tokens from past timestamp ledgers, it becomes possible to prevent tampering with past timestamp ledgers, thus increasing reliability.
[0036] [Differentiation] Next, a modified version of the timestamp issuance system described above will be explained. The timestamp issuance unit 11 of the local time authentication authority server 10 may generate a timestamp ledger as shown in Figure 6 and store it in the ledger storage unit 16 when issuing a timestamp token. Specifically, the record of the issued timestamp token stored in the timestamp ledger in the modified version consists of a combination of the hash value of the electronic data, time information, the timestamp token, and the fuzzy hash value of the electronic data. A fuzzy hash value is one type of hash value of electronic data, and it is calculated using a function that takes close values to similar electronic data. Examples of fuzzy hash values include hash functions such as imphash and ssdeep.
[0037] Then, as described above, when the pre-set timing occurs, the ledger timestamp request unit 12 of the local time certification authority server 10 requests a timestamp for the timestamp ledger containing the fuzzy hash value stored in the ledger storage unit 16, as shown in Figure 6, from the official time certification authority server 30 located on the external internet N. At this time, the ledger timestamp request unit 12 may also include a ledger timestamp token previously obtained from the official time certification authority server 30 in the new timestamp ledger for which a timestamp is to be requested, and request a timestamp for that new timestamp ledger.
[0038] As described above, by including the fuzzy hash value of the electronic data in the timestamp ledger and obtaining a timestamp from the official time authentication authority server 30, it becomes easier to search for electronic data similar to the verified electronic data using the fuzzy hash value, and verification can also be performed on similar electronic data.
[0039] <Embodiment 2> Next, a second embodiment of the present invention will be described with reference to Figures 7 to 9. Figures 7 to 8 are block diagrams showing the configuration of the local time stamp issuing device in Embodiment 2, and Figure 9 is a flowchart showing the operation of the local time stamp issuing device. In this embodiment, the configuration of the local time authentication authority server 10 and the local time stamp issuing method described in the above-described embodiment is shown in outline.
[0040] First, with reference to Figure 7, the hardware configuration of the local timestamp issuing device 100 in this embodiment will be described. The local timestamp issuing device 100 is composed of a general information processing device, and as an example, it is equipped with the following hardware configuration. ·CPU(Central Processing Unit)101(Arithmetic unit) ROM (Read Only Memory) 102 (Storage Device) • RAM (Random Access Memory) 103 (Storage Device) • Program group 104 loaded into RAM 103 • Storage device 105 for storing the program group 104 • Drive device 106 for reading and writing to external storage medium 110 of the information processing device. • Communication interface 107 connecting to a communication network 111 outside the information processing device. • Input / output interface 108 for data input and output. • Bus 109 connecting each component
[0041] The local timestamp issuing device 100 can be equipped with the timestamp issuing unit 121, ledger timestamp request unit means 122, and ledger timestamp acquisition unit 123 shown in Figure 8, by having the CPU 101 acquire the program group 104 and execute it. The program group 104 is stored in a storage device 105 or ROM 102 in advance, for example, and the CPU 101 loads it into RAM 103 and executes it as needed. The program group 104 may also be supplied to the CPU 101 via a communication network 111, or it may be stored in a storage medium 110 in advance, and the drive device 106 reads the program and supplies it to the CPU 101. However, the timestamp issuing unit 121, ledger timestamp request unit means 122, and ledger timestamp acquisition unit 123 described above may be constructed with dedicated electronic circuits to realize such means.
[0042] Figure 7 shows an example of the hardware configuration of the information processing device, which is the local timestamp issuing device 100. The hardware configuration of the information processing device is not limited to the case described above. For example, the information processing device may consist of only a part of the configuration described above, such as not having the drive device 106.
[0043] Then, the local time stamp issuing device 100 executes the local time stamp issuing method shown in the flowchart of Figure 9, based on the functions of the time stamp issuing unit 121, the ledger time stamp request unit means 122, and the ledger time stamp acquisition unit 123, which are constructed by the program as described above.
[0044] As shown in Figure 9, the local timestamp issuing device 100 installed in an offline environment is In response to a request for a timestamp for electronic data from a predetermined information processing device installed in the same local environment as the local timestamp issuing device, a timestamp token is issued for the electronic data (step S101). At a predetermined timing, connect to a specific timestamp issuing device installed on the internet and request a timestamp from the said specific timestamp issuing device for the ledger data including the timestamp token issued for the electronic data (step S102), Obtain the timestamp token issued for the ledger data from the specified timestamp issuing device (step S103). This process is executed.
[0045] As described above, the present invention allows timestamp tokens included in ledger data to be proven to have existed at a predetermined time and not to have been tampered with after that time, based on a timestamp issued by a specific timestamp issuing device. This increases the reliability of verifying electronic data using timestamp tokens issued by a local timestamp issuing device. As a result, highly reliable timestamps can be issued even when using a timestamp issuing device in an offline environment.
[0046] The programs described above can be stored and supplied to a computer using various types of non-transitory computer-readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / Ws, and semiconductor memory (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash ROMs, and RAMs (Random Access Memory)). Programs may also be supplied to a computer using various types of transient computer-readable media. Examples of transient computer-readable media include electrical signals, optical signals, and electromagnetic waves. Transitory computer-readable media can be supplied to a computer via wired communication channels such as electric wires and optical fibers, or via wireless communication channels.
[0047] Although the present invention has been described above with reference to the embodiments described above, the present invention is not limited to the embodiments described above. Various modifications to the configuration and details of the present invention can be made within the scope of the present invention as can be understood by those skilled in the art. Furthermore, at least one of the functions of the time stamp issuing unit 121, the ledger time stamp request unit means 122, and the ledger time stamp acquisition unit 123 described above may be performed on an information processing device installed and connected at any location on the network, that is, it may be performed using so-called cloud computing.
[0048] <Note> Some or all of the above embodiments may also be described as follows. The general configuration of the local timestamp issuance method, local timestamp issuance device, and program in the present invention will be described below. However, the present invention is not limited to the following configuration. (Note 1) A method for issuing timestamps using a local timestamp issuing device installed in an offline environment, In response to a request for a timestamp for electronic data from a predetermined information processing device installed in the same local environment as the local timestamp issuing device, a timestamp token is issued for said electronic data. At a predetermined time, connect to a specific timestamp issuing device located on the internet and request a timestamp from that specific timestamp issuing device for the ledger data, including the timestamp token issued for the electronic data. A timestamp token issued for the ledger data from the specified timestamp issuing device is obtained. How to issue a timestamp. (Note 2) The method for issuing a timestamp as described in Appendix 1, To the specified timestamp issuing device, a timestamp is requested for the ledger data, which includes the timestamp token issued by the local timestamp issuing device, after the last time a timestamp was requested from the specified timestamp issuing device. How to issue a timestamp. (Note 3) A method for issuing a timestamp as described in Appendix 1 or 2, To request a timestamp for the ledger data, which includes multiple timestamp tokens issued by the local timestamp issuing device, from the specified timestamp issuing device. How to issue a timestamp. (Note 4) A method for issuing a timestamp as described in any of the appendices 1 to 3, Periodically, at pre-set timings, connect to the specific timestamp issuing device and request a timestamp from the said specific timestamp issuing device. How to issue a timestamp. (Note 5) A method for issuing a timestamp as described in any of the appendices 1 to 4, In response to a request for a timestamp for the electronic data from the predetermined information processing device, a timestamp token is issued, which is electronically signed by adding time information to the hash value of the electronic data. A request is made to the specified timestamp issuing device for a timestamp on the ledger data, which includes the hash value, the time information, and the timestamp token issued for the electronic data. How to issue a timestamp. (Note 6) The method for issuing a timestamp as described in Appendix 5, A request is made to the specified timestamp issuing device for a timestamp on the ledger data, which includes the hash value, the time information, the timestamp token issued for the electronic data, and the fuzzy hash value of the electronic data. How to issue a timestamp. (Note 7) A method for issuing a timestamp as described in any of the appendices 1 to 6, At a predetermined timing, a request is made to the specified timestamp issuing device to include a timestamp token previously obtained from the specified timestamp issuing device in the ledger data, and to request a timestamp for the said ledger data. How to issue a timestamp. (Note 8) The method for issuing a timestamp as described in Appendix 7, At a predetermined timing, the system requests a timestamp from the specified timestamp issuing device, including a timestamp token obtained from the specified timestamp issuing device in the most recent past in the ledger data, and requests a timestamp for the said ledger data. How to issue a timestamp. (Note 9) A local timestamp issuing device installed in an offline environment, A timestamp issuing unit that issues a timestamp token for electronic data in response to a request for a timestamp for electronic data from a predetermined information processing device installed in the same local environment as the local timestamp issuing device, A ledger timestamp request unit connects to a specific timestamp issuing device located on the internet at a predetermined timing and requests a timestamp from the said specific timestamp issuing device for the ledger data, which includes the timestamp token issued for the electronic data. A ledger timestamp acquisition unit that acquires a timestamp token issued for the ledger data from the specified timestamp issuing device, A local timestamp issuing device equipped with the following features. (Note 9.1) The time stamp issuing device described in Appendix 9, The ledger timestamp request unit requests the specific timestamp issuing device to issue a timestamp for the ledger data, which includes the timestamp token issued by the local timestamp issuing device after the last time a timestamp was requested from the specific timestamp issuing device. Timestamp issuing device. (Appendix 9.2) A time stamp issuing device as described in Appendix 9 or 9.1, The ledger timestamp request unit requests the specific timestamp issuing device to perform a timestamp on the ledger data, which includes a plurality of timestamp tokens issued by the local timestamp issuing device. Timestamp issuing device. (Appendix 9.3) A time stamp issuing device as described in any of Appendix 9 to 9.2, The ledger timestamp request unit periodically connects to the specific timestamp issuing device at a predetermined time and requests a timestamp from the specific timestamp issuing device. Timestamp issuing device. (Appendix 9.4) A time stamp issuing device as described in any of Appendix 9 to 9.3, The timestamp issuing unit, in response to a request for a timestamp for the electronic data from the predetermined information processing device, issues a timestamp token that has been digitally signed by adding time information to the hash value of the electronic data. The ledger timestamp request unit requests the specific timestamp issuing device to perform a timestamp on the ledger data, which includes the hash value, the time information, and the timestamp token issued for the electronic data. Timestamp issuing device. (Note 9.5) A timestamp issuing device as described in Appendix 9.4, The ledger timestamp request unit requests the specific timestamp issuing device to perform a timestamp on the ledger data, which includes the hash value, the time information, the timestamp token issued for the electronic data, and the fuzzy hash value of the electronic data. Timestamp issuing device. (Appendix 9.6) A time stamp issuing device as described in any of Appendix 9 to 9.5, The ledger timestamp request unit requests a timestamp for the ledger data from the specific timestamp issuing device at a predetermined timing, including a timestamp token previously obtained from the specific timestamp issuing device in the ledger data. Timestamp issuing device. (Note 9.7) A timestamp issuing device as described in Appendix 9.6, The ledger timestamp request unit requests a timestamp for the ledger data from the specific timestamp issuing device at a predetermined timing, including a timestamp token obtained from the specific timestamp issuing device in the most recent past in the ledger data. Timestamp issuing device. (Note 10) A local timestamp issuing device installed in an offline environment, In response to a request for a timestamp for electronic data from a predetermined information processing device installed in the same local environment as the local timestamp issuing device, a timestamp token is issued for said electronic data. At a predetermined time, connect to a specific timestamp issuing device located on the internet and request a timestamp from that specific timestamp issuing device for the ledger data, including the timestamp token issued for the electronic data. A timestamp token issued for the ledger data from the specified timestamp issuing device is obtained. A program to execute a process. [Explanation of symbols]
[0049] 10. Local Time Certification Authority Server 11 Timestamp Issuance Department 12 Ledger Timestamp Request Section 13. Ledger Timestamp Acquisition Unit 14 Verification Department 16 Ledger Storage Unit 20 User Terminals 30 Official Matters Certification Authority Server N External Network n Local network U User 100 Local Timestamp Issuer 101 CPU 102 ROM 103 RAM 104 Program Groups 105 Storage device 106 Drive unit 107 Communication Interface 108 Input / Output Interfaces 109 Bus 110 Storage medium 111 Communication Network 121 Timestamp Issuance Department 122 Ledger Timestamp Request Section 123 Ledger Timestamp Acquisition Unit
Claims
1. A method for issuing timestamps using a local timestamp issuing device installed in an offline environment, In response to a request for a timestamp for electronic data from a predetermined information processing device installed in the same local environment as the local timestamp issuing device, a timestamp token is issued for the electronic data, which is electronically signed by adding time information to the hash value of the electronic data. At a predetermined timing, connect to a specific timestamp issuing device installed on the internet and request a timestamp from the said timestamp issuing device for ledger data containing multiple records, each record containing one combination of the hash value, the time information, and the timestamp token issued for the electronic data. A timestamp token issued for the ledger data from the specified timestamp issuing device is obtained. How to issue a timestamp.
2. A method for issuing a timestamp according to claim 1, To request a timestamp from the specified timestamp issuing device for the ledger data which includes multiple records containing timestamp tokens issued by the local timestamp issuing device since the last time a timestamp was requested from the specified timestamp issuing device, How to issue a timestamp.
3. A method for issuing a time stamp according to claim 1 or 2, Periodically, at predetermined timings, connect to the specific timestamp issuing device and request a timestamp from the said specific timestamp issuing device. How to issue a timestamp.
4. A method for issuing a timestamp according to any one of claims 1 to 3, A request is made to the specified timestamp issuing device for a timestamp on the ledger data which includes a plurality of records, each of which includes the hash value, the time information, the timestamp token issued for the electronic data, and the fuzzy hash value of the electronic data. How to issue a timestamp.
5. A method for issuing a timestamp according to any one of claims 1 to 4, At a predetermined timing, a request is made to the specified timestamp issuing device to include a timestamp token previously obtained from the specified timestamp issuing device in the ledger data, and to request a timestamp for the said ledger data. How to issue a timestamp.
6. A method for issuing a time stamp according to claim 5, At a predetermined timing, a request is made to the specific timestamp issuing device to include a timestamp token obtained from the specific timestamp issuing device in the most recent past in the ledger data, and to request a timestamp for the said ledger data. How to issue a timestamp.
7. A local timestamp issuing device installed in an offline environment, A timestamp issuing unit that, in response to a request for a timestamp for electronic data from a predetermined information processing device installed in the same local environment as the local timestamp issuing device, issues a timestamp token for the electronic data, which is an electronically signed timestamp token obtained by adding time information to the hash value of the electronic data, A ledger timestamp request unit connects to a specific timestamp issuing device installed on the internet at a predetermined timing and requests a timestamp from the said specific timestamp issuing device for ledger data that includes multiple records, each record containing one combination of the hash value, the time information, and the timestamp token issued for the electronic data. A ledger timestamp acquisition unit that acquires a timestamp token issued for the ledger data from the specified timestamp issuing device, A local timestamp issuing device equipped with the following features.
8. A local time stamp issuing device according to claim 7, The ledger timestamp request unit requests a timestamp for the ledger data from the specific timestamp issuing device at a predetermined timing, including a timestamp token previously obtained from the specific timestamp issuing device in the ledger data. Local timestamp issuing device.
9. A local timestamp issuing device installed in an offline environment, In response to a request for a timestamp for electronic data from a predetermined information processing device installed in the same local environment as the local timestamp issuing device, a timestamp token is issued for the electronic data, which is electronically signed by adding time information to the hash value of the electronic data. At a predetermined timing, connect to a specific timestamp issuing device installed on the internet and request a timestamp from the said timestamp issuing device for ledger data containing multiple records, each record containing one combination of the hash value, the time information, and the timestamp token issued for the electronic data. A timestamp token issued for the ledger data from the specified timestamp issuing device is obtained. A program to execute a process.