JP2002244554A - Method for generating and confirming time stamp, and device and system therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure sufficient genuineness that could be a piece of evidence for a trial at inexpensive cost, relating to data handled by a computer. SOLUTION: This method comprises a 1st step for updating a count value of a counter each time input data are accepted or at predetermined time intervals, and a 2nd step for generating digital signatures of the accepted input data and count value of the counter by using a pre-registered signature key and outputting the generated digital signatures and the count value as time stamps presenting the accepting order or the accepted time of the input data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for generating and confirming a time stamp for confirming when to create or update data to be handled by a computer.

[0002]

2. Description of the Related Art In order for data such as a purchase order and accounting to be handled by a computer as evidence of a trial, it is necessary to show proof that the data has not been changed after creation and when the data was created or updated. Generally, an operating system (OS) of a computer has a function of recording the last update date and time. Therefore, there is a method in which the creation date and time or the update date and time are added to the target data and stored using the function of the OS. On the other hand, as a method of leaving evidence using a trusted third party, the Internet Public Key Infrastructure Committee (Internet Engineering Task Force)
Public Key Infrastructure X.509 Working Group)
There is a method that uses a time stamp protocol that is being drafted. In this protocol, when the user sends the hash value of the target data to the server, the server signs the hash value along with the date and returns it to the user, so that this data can be used as evidence.

[0003]

However, the information of the last update date and time provided by the OS of the computer can be obtained by changing the internal clock of the computer or by directly accessing data on the disk without going through the OS. By faking the last update date and time, it is possible to fake data that is convenient for him. For this reason, there is a problem that it is not possible to secure sufficient authenticity that can be evidence of a trial. Further, in the method using the time stamp protocol, there is a problem that a trusted third-party organization needs to open and operate the server, and the establishment of the organization is costly.

[0004] It is an object of the present invention to provide a time stamp generation method, a confirmation method, an apparatus and a system which can secure sufficient authenticity which can be used as evidence of a trial at low cost with respect to data handled by a computer. It is in.

[0005]

In order to achieve the above object, the present invention provides a first step of updating a count value of a counter each time input data is received, a step of updating the count value of the counter, and a step of updating the count value of the counter. Generating a digital signature using a previously registered signature key, and outputting the generated digital signature and the count value as a time stamp indicating the order of acceptance of input data. And Further, a first step of receiving the input data and updating the count value of the counter, and generating and generating a digital signature of the received input data and the count value of the counter using a previously registered signature key, A second step of outputting the digital signature and the count value as a time stamp indicating an acceptance time;
And a third step of performing predetermined processing so that processing including the first and second steps is performed at predetermined time intervals. Then, the processing of each step is performed in an IC card. The method further includes storing the digital signature output in the second step and the count value in a time stamp table together with identification information of data to be subjected to a time stamp. The method further includes storing the digital signature output in the second step and the count value in a time stamp table together with the identification information of the data to be subjected to the time stamp and the current date and time information.

A step of generating, as the input data, a third hash value of a first hash value of the data to be provided with a time stamp and a second hash value of another data to be provided with a time stamp immediately before; It is characterized by having. A step of generating, as the input data, a third hash value of a first hash value of the data to be provided with a time stamp, update date and time data, and a second hash value of another data to be provided with a time stamp added immediately before; It is characterized by having.

Further, in the time stamp confirmation method according to the present invention, the third hash value of the first hash value of the time stamp addition target data and the second hash value of the other time stamp addition target data added immediately before is provided. The digital signature of the target data management table stored in the order in which the time stamps are provided, the third hash value as input data, and the count value of a counter whose count value is updated each time the input data is received, and the count value are timed. A time stamp table stored as a stamp, and sequentially manages the first to third hash values of other time-stamped data to which a time stamp has been added after the time-stamped data to be checked. Obtained from the table and the first to third hash values are correct. A first step of confirming that,
Determine the consistency between the third hash value of the time-stamped data to be verified and the digital signature of the time-stamped data to be verified stored in the time stamp table. Outputting a count value stored together with the digital signature of the time-stamped data as information indicating the order in which the time-stamped data is received. A target data management table that stores a third hash value of the first hash value of the time stamp addition target data and the second hash value of another time stamp addition target data added immediately before in the order of the time stamp addition; A digital signature of a counter value that receives the third hash value as input data, and a count value of which is updated at predetermined time intervals, and a time stamp table that stores the count value as a time stamp. The first to third hash values of other time-stamped data to which a time stamp is added after the given time-stamped data are sequentially obtained from the target data management table, and the first to third hash values are obtained. First step to confirm that the file is correct, and a timestamp to be checked It is determined whether or not the third hash value of the completed data matches the digital signature of the time-stamped data to be confirmed stored in the time stamp table, and if both match, the time stamp is added. And outputting a count value stored together with the digital signature of the already-processed data as information indicating the reception time of the time-stamped data.

Further, the time stamp generating apparatus according to the present invention is characterized in that first time processing means for updating the count value of the counter each time input data is received, receiving the input data, and comparing the input data with the count value of the counter. And a second processing means for generating a digital signature of the digital signature using a pre-registered signature key and outputting the generated digital signature and the count value as a time stamp. First processing means for receiving input data and updating the count value of the counter; and generating a digital signature of the received input data and the count value of the counter using a previously registered signature key. Second processing means for outputting the obtained digital signature and the count value as a time stamp, and third processing means for performing predetermined processing so that processing by the first and second processing means is performed at predetermined time intervals. And characterized in that:
The generation device is configured by an IC card having a storage function and an arithmetic function.

A time stamp management system according to the present invention comprises a time stamp generation device and a time stamp management device for receiving data and generating and managing a time stamp indicating an order of receiving the data. A first processing unit that updates a count value of a counter each time input device receives input data; and generates a digital signature of the received input data and the count value of the counter using a previously registered signature key. ,
A second processing unit that outputs the generated digital signature and the count value as a time stamp, wherein the time stamp management device adds another hash value that is added immediately before the first hash value of the time stamp addition target data. A third hash value with the second hash value of the data to be time-stamped is generated and stored in the target data management table in the order of the time stamps, and the stored third hash value is stored in the input data of the time stamp generation device. And a fourth processing unit for storing a time stamp output from the time stamp generation device in a time stamp table.

A time stamp generating apparatus and a time stamp managing apparatus for receiving data and generating and managing a time stamp indicating the time of receiving the data, wherein the time stamp generating apparatus receives input data, First processing means for updating the count value of the counter at intervals; generating a digital signature of the received input data and the count value of the counter using a previously registered signature key; A second processing unit that outputs the count value and the time stamp as the time stamp, wherein the time stamp management device outputs the first hash value of the time stamp addition target data and another time stamp addition target data added immediately before. A third hash value with the second hash value is generated, and the target data management data is generated in the order of the time stamp. And third processing means for outputting the stored third hash value as input data of the time stamp generating device, and storing the time stamp output from the time stamp generating device in a time stamp table. And a fourth processing unit. Then, the time stamp management device sequentially performs the first to third hash values of other time stamped data to which a time stamp is added after the time stamped data to be checked for the time stamp. The fourth is obtained from the management table and confirms that the first to third hash values are correct.
And whether or not the third hash value of the time-stamped data to be verified matches the digital signature of the time-stamped data to be verified stored in the time stamp table. And a fifth processing unit that outputs a count value stored together with the digital signature of the time-stamped data as information indicating the reception timing of the time-stamped data when both match. Features.

According to the present invention, a time stamp indicating the order of creation or update of data handled by a computer is generated and output. Alternatively, it generates and outputs a time stamp indicating a data creation time or an update time. In this case, a time stamp is generated using a built-in counter and a signature key in the IC card. It is impossible for an IC card to rewrite or take out internal information or a program by an external instruction except for the manufacturer. Therefore, it is impossible to falsify the count value, the signature key, and the program for the generation process. Therefore, the time stamp generated and output cannot be tampered with from the outside. If a set of the time stamp and the input data is stored in a pair, the creation order or the creation time of the input data or the update order is determined by the time stamp. In addition, it is possible to confirm the renewal time, and secure sufficient authenticity that can be used as evidence of a trial or the like. In the present invention, the time stamp can guarantee that the target data is created or updated before the order (or time) indicated by the count value of the counter. In other words, the time stamp can guarantee that the target data has not been created or updated after the order (or time) indicated by the count value of the counter.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a system configuration diagram showing an embodiment of a document management system to which the present invention is applied. The system is roughly divided into a stamp processing computer 101, a stamp IC card 102, and an IC card reading / writing device (hereinafter, I / O device).
C card R / W) 103. The stamp processing computer 101 and the stamp IC card 102
Data is transferred through the C card R / W 103.
The stamp processing computer 101 is an application program 1 for creating and editing document data such as a word processor.
011 operates under the control of the operating system (OS) 1102.

The operating system 1102 includes:
File management unit 1103 and file update table (target data management table) 1104 used for time stamp processing
And time stamp table (time stamp table) 11
05 is provided and the application program 1
The document data created or updated by 011 is stored in the storage device 104 by the file management unit 1103. In this case, a time stamp is generated and recorded in the time stamp table 1105 each time document data is created or updated. On the other hand, the stamp IC card 102 includes an input / output device 1021, an arithmetic device 1022, a counter 1023, and a signature key 1024 stored in a storage area.

Each time the application program 1011 creates or updates document data and stores the document data in the storage device 104, the stamp processing computer 101 configured as described above sends a time stamp to the stamp IC card 102 via the IC card R / W 103. Send the stamp generation command and the data to be generated. In the stamp IC card 102, the input / output device 1021 receives the time stamp generation command and the data command to be generated,
Pass to. The arithmetic device 1022 signs the count value of the counter 1023 and the input data with the signature key 1024, and sends the signature result and the count value as a time stamp to the stamp processing computer 101 via the IC card R / W 103. Here, the signature key 1024 corresponds to a secret key if the signature processing is based on, for example, the RSA encryption. Note that the present invention uses R
It is not limited to SA.

The count value of the counter 1023 is
When the time stamp guarantees the order of the data, the count value is updated by one each time the data to be signed is input to the stamp IC card 102. However, in the case of guaranteeing the data creation or update timing, the count value is updated, for example, at one-second intervals, so as to have a function equivalent to a clock. The process of giving the counter 1023 a clock function will be described later. The stamp processing computer 101 records the time stamp received from the stamp IC card 102 together with the identification number of the document data in the time stamp table 1105.

FIG. 2 shows an example of the configuration of the file update table 1104. One record corresponding to one row is composed of the following column data. That is, the identification number 201 for uniquely identifying the record in the table, the storage device 10
File name 20 that uniquely identifies the document file in
2. File hash value 203 for the document data in the file, update date 204 of the document data in the file,
Stamp value 205 input to stamp IC card 102
It is composed of Although the file name 202 is represented using a character string, other identification information such as a storage position in the storage device 104 may be used. Also, the file hash value 203 is generated from a hash function,
The description is omitted because it has no relation to the gist of the present invention. The update date / time 204 is represented using, for example, the total number of seconds since 00:00:00 on January 1, 1970.

FIG. 3 shows an example of the configuration of the time stamp table 1105. One record corresponding to one row is composed of the following column data. That is, a record creation date and time 301, an identification number 302 for identifying a record in the file update table 1104 in FIG. 2, a count value 303 for this record, a stamp IC card 102
From the time stamp 304 obtained from the

FIG. 4 is a flowchart showing processing of the file update table 1104, FIG. 5 is a flowchart showing processing of the time stamp table 1105, and FIG. 6 is a flowchart showing processing in the stamp IC card 102. First,
The file update table processing will be described in detail with reference to FIG. In this file update processing, first, in step 401, the file management unit 110 in the OS 1102
3, the file update of the document data is detected. This detection method includes, for example, OPE
There is a method of detecting and implementing an event in which an N-file is closed. Similarly, there is a method of detecting when data is written to an opened file. Since the details of the detection method are out of the scope of the present invention, further description is omitted.

Next, in step 402, a file update record record is added to the file update table 1104. The additional method is as follows. First, one new record is added. Next, the identification number 201 is written. The identification number 201 is obtained by increasing the identification number 201 of the immediately preceding record by one. Next, the updated file name 202 is written. Next, the updated hash value of the file content (document data) is written to the file hash value 203. Next, the update date / time 204 is written.
The update date and time 204 is obtained from the clock function of the OS 1102. Finally, the stamp value 205 is written. The stamp value 205 includes a file name 202, a file hash value (first hash value) 203, and an update date and time 20.
The stamp value of the 4th and previous record (second hash value)
205 is the hash value (third hash value). For example, when focusing on the record with the identification number 201 = 5,
"Bar.txt", "3fe03fe3ab41cd113c", "0010234"
Hash values “3ef20a3f” of “3” and “4f3390cd” are written.

By performing such processing, the falsification detection data of the file names and file contents of all the records and the update date and time is created. This is because the hash value for the file name, file content, or update date and time of a certain record is included in the stamp value 205, and the hash value of the stamp value 205 is included in the stamp value of the next record.

Next, the time stamp table processing of FIG. 5 will be described in detail. This process is a loop process including the card process shown in FIG. That is, step 50
The processing shown in 1, 502, and 503 is continuously repeated without an infinite interval. First, in step 501, the latest record of the file update table 1104 is obtained. Next, in step 502, the stamp value 205 of the latest record is sent to the stamp IC card 102. FIG. 6 shows the processing in the stamp IC card 102. Next, in step 503, a new record of the time stamp table 1105 is created, and the count value 303 and the time stamp 30 returned from the stamp IC card 102 are created.
4 is stored together with the identification number 201 of the latest record in the file update table 1104 and the date and time of creation. The identification number is 302
The creation date is stored in 301.

Next, the card processing of FIG. 6 will be described. The card processing shown in FIG.
No. 4 shows an example in which the file creation time or the update time is confirmed. If an attempt is made to generate a time stamp for confirming the creation time or update time instead of the file creation or update order, a stamp IC
It is necessary to provide the card 102 with a clock function. In the present invention, the counter 1023 in the stamp IC card 102 is used.
, A time stamp generation command is continuously given from the stamp processing computer 101, and the processing shown in FIG. 6 is repeated without interruption in units of one second, for example. Has been realized. When generating a time stamp that guarantees the order of file creation or update, the time stamp generation command may be given to the stamp IC card 102 each time a file to be generated is detected.

In FIG. 6, first, at step 601, the stamp processing computer 101 receives the stamp value 205 sent at step 502. Next, a certain amount of processing is performed in step 602. This process is performed on the stamp IC card 10
2, since it is a process for increasing the processing time, the stamp IC card 102 has nothing to do with the original process. For example, it is a process of calculating "1 + 1" 1000 times, or a process of encrypting and decrypting certain data one million times. Next, after increasing the count value of the counter 1023 by one in step 603, the stamp value 2 is increased in step 604.
Signing is performed using the signature key 1024 on data obtained by adding the count value of the counter 053 and the count value of the counter 1023. Finally, in step 605, the stamp value 205 and the signature generated in step 604 are output to the stamp processing computer 101.

The processing shown in FIG.
As long as the time stamp generation command is given from 01, it is repeated without interruption. The repetition time interval is set to, for example, one second by appropriately selecting the processing content of step 602. As a result, the counter 1023 functions as a clock that updates the date and time at one-second intervals.

If the counter value of the counter 1023 in the IC card 102 and the signature generated in the signature step 604 are registered in the time stamp table 1105,
This is evidence that the target data (stamp value 205) exists at the date and time corresponding to the count value. For example, "200
It is assumed that the count value of “October 10, 00: 00: 10: 10” is “304590” and the count value “30453”
It is assumed that the data and the signature at the time of “0” exist. Then, it can be said that the present data existed before at least the difference between the count values “60 × (processing time in card)”. Since the processing time in the IC card 102 takes one second, it can be seen that the data corresponding to the count value “304530” existed before “10: 09: 10,2000, October 10, 2000”.

If the above processing is temporarily stopped for some reason, the increase in the count value will be smaller than the elapsed time. For example, it is assumed that the operation has been stopped for 20 seconds from “10:10:30 on October 11, 2000”. The count value is “10:11 on October 11, 2000.
Assuming that the count value of “minute 10 seconds” is “305990”, the count value “305930” actually corresponds to “9 minutes 50 seconds”, but there is no evidence that it has stopped. It is determined that the count value is “10 seconds”. It is preferable to leave evidence of the time as accurate as possible, but in the sense of preservation of evidence, "10 minutes 10 minutes
It is possible to guarantee that the data was generated before "seconds".

In the file update table 1104 of FIG. 2, the hash value of the file name 202, the file hash value 203, the update date and time 204, and the stamp value 205 of the previous record are used as the stamp value 205 of the new record. , Of which the required is the file hash value 20
3, the file hash value other than the file hash value 203 can be added to the hash value calculation target as needed. Further, the creation date and time 301 provided by the OS 1102 is also registered in the time stamp table 1105 in FIG. 3, but the date and time data indicated by the creation date and time 301 can be registered as necessary. This is because the creation date and time 301 provided by the OS 1102 can be falsified. However, if you register,
Although it may not be sufficient for evidence such as a trial, it can be used as a reference when a file is created or updated.

FIG. 7 is a flowchart showing a process for confirming the creation date and time or the update date and time of a document in which a time stamp is registered. First, in step 701, a record of a file whose update date and time is to be confirmed is searched from the file update table 1104 of FIG. In this case, if a plurality of records exist with the same file name, the latest one, that is, the identification number 201
Finds the record with the largest number. For example, file name = fo
o. When searching for txt, in FIG.
01 has records of “4”, “6”, and “8”, but selects a record with an identification number “8” having a large identification number and a new update date and time.

Next, at step 702, the same identification number 30 as the identification number 201 of the record found at step 701 in the time stamp table 1105 of FIG.
A record having the oldest creation date / time 301 after the record having 2 is searched for. Here, since the identification number is “8”, the time “001”, which is a record whose time is older after that, is “001”.
04401 ". Next, step 703
, The file update table 1 corresponding to the record selected in step 702 from the record selected in step 701
It is confirmed whether the records in the records 104 are consistent.

More specifically, for example, the record with the identification number 8 is selected in step 701. Step 7
The record selected in 02 is the record of the identification number 8 in the record of the file update table 1104 for the time “00104401”. Therefore, a record whose identification number 302 is “8” is searched from the file update table 1104,
Check whether the record in which 2 is “8” is correct. Specifically, for the record with the identification number 8, first, the hash value of the file content is calculated, and the same as the file hash value 203 in the record is confirmed.
2, the file hash value 203, the update date and time 204, and the hash value of the stamp value 205 of the record with the identification number 7 which is the previous record are calculated, and the current record (identification number =
Check whether it is the same as the stamp value of 8). If they are the same, it means that the data between the records with the identification numbers = 7 to 8 is correct. If there is no record with the identification number 302 = 8 in the time stamp table 1105, the identification number 201 = 8 in the file update table 1104 is used.
Check records from to.

Next, in step 704, it is confirmed whether or not the time stamp 304 of the record searched in step 702 is correct. Specifically, it is checked whether the signature of the stamp value 205 and the count value 303 of the file update table 1104 corresponding to the record becomes the time stamp 304. In the above example, the stamp value 205 of the identification number 8 of the file update table 1104 = “4ffadf28” and the count value 303 of the time stamp table 1105 = “23”
It is confirmed whether "5" corresponds to the time stamp 304 = "3a03efa8". That is, the third hash value (stamp value 205) of the time-stamped data to be confirmed matches the signature (time stamp 304) of the time-stamped data to be confirmed stored in the time stamp table 1105. It is determined whether or not to perform.

Next, in step 705, it is checked whether the counter value 303 of the record searched in step 702 matches the current time. Specifically, the creation date and time 30
The difference between the time registered in 1 and the current date and time is the count value 3
It is checked whether or not it corresponds to the difference between the number 03 and the current count value, that is, whether it is consistent with one card processing time. When they match, it can be considered that the counter 1023 is continuing the counting operation normally. Finally, in step 706, the count value 303 of the record to be confirmed is output as information indicating the reception time of the time-stamped data. Note that the count value 303
The determination as to whether or not matches the current date and time can be omitted. That is, when the counter 1023 is used as a clock function, the count value represents the date and time, so that the person in charge of confirmation checks whether or not the count value at the time of confirmation matches the current date and time. This is because if they do not match, the count value 303 output in step 706 may not be adopted as evidence.

It should be noted that the count value of the counter 1023 does not need to directly indicate the value of the current date and time. For example,
The count value 303 of the record with the identification number = 8 in FIG. 3 is “235”, and it cannot be understood that this alone represents the date and time directly. In such a case, the count value may be output via a process of converting the count value into date and time.

As described above, according to the present embodiment, a time stamp indicating the creation order or update order of data such as documents handled by a computer is generated and output. Alternatively, it generates and outputs a time stamp indicating a data creation time or an update time. In this case, since the time stamp is generated using the built-in counter and the signature key in the IC card, it is impossible to alter the count value, the signature key, and the program for the generation process. Therefore, the time stamp generated and output cannot be falsified from the outside. By storing a pair of the time stamp and the input data as a pair, the time stamp can be used to create or change the order of the input data or the time of the update. The order and renewal time can be confirmed, and sufficient authenticity that can be used as evidence of a trial or the like can be secured. As a preferred example to which the present invention is applied, a system that handles data such as purchase orders, sales orders, wills, and various identification cards related to the purchase and sale of stocks and various commodities.

In FIG. 1, a system for generating a time stamp for a document created or updated by the application program 1011 of the stamp processing computer 101 has been described as an example. The present invention can also be applied to a system in which a time stamp is generated and registered for such data. FIG. 8 is a system configuration diagram showing the example. 8 differs from FIG. 1 in that the document registration reception server 803 is operated as an application in the stamp processing computer 101, and the document data received by the document registration reception server 801 from the document registration client 803 via the Internet 802. Alternatively, the time stamp generated by the IC card 102 is stored in the time stamp table 11 under the management of the file management unit 1103 for the image data.
05. In this case, the document data or the image data is stored in the storage device 104. The same parts as those in FIG. 1 are denoted by the same reference numerals.

FIG. 9 is a flowchart showing the procedure of the document registration process in the configuration of FIG.
In step 01, the user specifies a document to be registered by the document registration client 803. FIG. 10 shows an example. On a screen 1000 in FIG. 10, a user identifier 1001, a password 1002 for authentication, and a document file name 1003 are specified. By clicking the registration button 1004 with a mouse, the document registration client 803 is instructed to register. Next, the document registration client 803 receiving the registration instruction in step 902 transmits the document data to the stamp processing computer 101 via the Internet 802. At the time of transmission, user authentication and encryption of document data are performed using the user identifier 1001 and the password 1002, but the details are not described because they are outside the scope of the present invention. In the next step 903, the stamp processing computer 101
Receives the document data, and the document registration reception server 801
The data is stored in the storage device 104 via S1102. Once stored, the file update table 110
The record corresponding to No. 4 is added.

Next, in step 904, the document registration receiving server 703 transmits the identification number 201 and the update date and time 204 of the record added to the file update table 1104 to the document registration client 803. Next, in step 905, the document registration client 803 displays the received identification number and update date and time as the document identification number and registration date and time. Figure 1
1 shows an example. In this example, the document name and the document size are shown in addition to the identification number and the registration date and time. With the configuration as shown in FIG. 8, even a computer user who does not have the stamp processing computer can be assured that the document has not been altered, and the role of the notary public can be changed to the stamp processing computer on the network. Can be realized.

Here, in the present embodiment, the user has explicitly designated a document to be recorded by the document registration client 803. With the following changes, evidence of file update for the entire file on the document registration client 803 can be obtained. That is, the document registration client 80
3 holds a file update table in the same manner as the stamp processing computer 101, and periodically identifies the identification number 201 of the latest record, the document name 1003, and the stamp value 20.
5 is sent to the document registration reception server 801 as file contents, processing corresponding to step 502 in FIG. 5 is performed periodically, and the document registration client 803 does not need to explicitly specify the document name. You can leave evidence of file updates for the entire file above.
Note that the present invention is not limited to the case where document data is registered via a network.
1 can be configured to read registered data from the tape reader 1201 connected to the device 1 and register a time stamp for the read data. The reading and writing of data with the tape reader 1201 are performed by a tape reading and recording program 1202.

As shown in FIG. 13, data transmitted from a large number of clients 1301-1 to 1301-n is received by the stamp processing computer 101 via the Internet 1302, and the received document or image data is received. , A time stamp is generated, the generated time stamp is added to the document data or the image data, and the time stamp is transmitted to the destination clients 1304-1 to 1304-m via the Internet 1303. In such a system, the time stamp generated by the stamp processing computer 101 itself is stored together with the data identification number, and each client 1301 as a transmission source is stored.
-1 to 1301-n store a file transfer table corresponding to the file update table. As a result, it is possible to leave evidence of the transmission order or the transmission date and time of the data transmitted by each of the transmission source clients 1301-1 to 1301-n. Therefore, if the present invention is applied to, for example, a system for buying and selling stock via the Internet, it is possible to present evidence of a dispute caused by misrecognition of the time of a buy order or a sell order.

[0040]

As is clear from the above description, according to the present invention, it is possible to secure sufficient authenticity that can be used as evidence of a trial at low cost with respect to data handled by a computer.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an embodiment of a document management system to which the present invention has been applied.

FIG. 2 is a diagram illustrating a configuration example of a file update table.

FIG. 3 is a diagram illustrating a configuration example of a time stamp table.

FIG. 4 is a flowchart showing processing of a file update table.

FIG. 5 is a flowchart showing processing of a time stamp table.

FIG. 6 is a flowchart showing processing in the IC card.

FIG. 7 is a flowchart illustrating a process of confirming a creation date and time or an update date and time of a document in which a time stamp is registered.

FIG. 8 is a system configuration diagram showing an example of a system for generating and registering a time stamp for data such as a document or an image received via a network.

FIG. 9 is a flowchart illustrating a procedure of a document registration process in the configuration of FIG. 8;

FIG. 10 is a diagram illustrating an example of a screen on which a user specifies a document to be registered by a document registration client.

FIG. 11 is a diagram showing an example of a screen displaying the identification number and the update date and time received by the document registration client, the document identification number and the registration date and time.

FIG. 12 is a diagram showing a configuration example of a system that reads registration data from a tape reader connected to a stamp processing computer and registers a time stamp for the read data.

FIG. 13 is a diagram showing an example of a system for transmitting and receiving data via a stamp processing computer.

[Explanation of symbols]

101: stamp processing computer, 102: stamp IC card, 103: IC card R / W, 104: storage device,
201: identification number, 202: file name, 203: file hash value, 204: update date and time, 205: stamp value, 301: creation date and time, 302: identification number, 303: count value, 304: time stamp, 801: document registration Reception server, 802, Internet, 803, Document registration client, 1011, Application program, 1102, Operating system, 1103,
File management unit, 1104: File update table, 1105
... Time stamp table, 1022 ... Calculator, 1023 ...
Counter, 1024 ... Signing key.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04L 9/10 H04L 9/00 621A (72) Inventor Takanori Tsukada 6-81 Onoecho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Address Hitachi Software Engineering Co., Ltd. In-house F-term (reference) 5B017 AA03 BA07 CA00 5J104 AA08 AA09 AA11 AA16 EA04 EA22 LA06 NA02 NA12 NA35 NA37 NA40 PA07

Claims (15)

[Claims] 1. A time stamp generating method for generating and outputting a time stamp indicating an order of receiving input data, comprising: a first step of updating a count value of a counter each time input data is received; And generating a digital signature of the counter and the count value of the counter using a pre-registered signature key, and outputting the generated digital signature and the count value as a time stamp. Timestamp generation method. 2. A time stamp generating method for generating and outputting a time stamp indicating a reception time of input data, comprising: a first step of receiving input data and updating a count value of a counter; A second step of generating a digital signature with the count value of the counter using a pre-registered signature key, and outputting the generated digital signature and the count value as a time stamp; And a third step of performing a predetermined process so that the process including the steps described above is performed at predetermined time intervals. 3. The time stamp generation method according to claim 1, wherein the processing of each step is performed in an IC card. 4. The method according to claim 1, further comprising the step of storing the digital signature output in the second step and the count value in a time stamp table together with identification information of data to be subjected to a time stamp.
Or the time stamp generation method according to 2. 5. The method according to claim 1, further comprising the step of storing the digital signature output in the second step and the count value in a time stamp table together with the identification information of the data to be subjected to the time stamp and the current date and time information. The time stamp generation method according to claim 1. 6. A step of generating, as the input data, a third hash value of a first hash value of data to be subjected to a time stamp and a second hash value of another data to be subjected to a time stamp added immediately before. The time stamp generation method according to claim 1, further comprising: 7. As the input data, a third hash value of a first hash value of data to be given a time stamp, update date / time data, and a second hash value of another data to be given time stamp, which is provided immediately before, is used. The time stamp generation method according to claim 1, further comprising a generation step. 8. Target data in which a third hash value of a first hash value of data to be subjected to a time stamp and a second hash value of another data to be subjected to a time stamp added immediately before is stored in the order of the time stamps. A management table, a digital signature of a counter value that receives the third hash value as input data, and a count value that is updated each time the input data is received, and a time stamp table that stores the count value as a time stamp. A time stamp confirmation method for confirming a time stamp indicating an acceptance order of time-stamped data, wherein other time-stamped data having a time stamp added after the time-stamped data to be checked The first to third hash values of A first step of acquiring from the management table and confirming that the first to third hash values are correct; a third hash value of time-stamped data to be confirmed and stored in the time stamp table; Check the consistency of the time-stamped data with the digital signature, and if they match, count the count value stored with the digital signature of the time-stamped data. A second step of outputting the information as information indicating the order of acceptance. 9. A target data in which a third hash value of a first hash value of data to be subjected to a time stamp and a second hash value of another data to be subjected to a time stamp added immediately before is stored in the order of the time stamps. A management table, and a time stamp table which receives the third hash value as input data, stores a digital signature with a count value of a counter whose count value is updated at predetermined time intervals, and stores the count value as a time stamp; A timestamp checking method for checking a timestamp indicating a reception time of data to which a timestamp has been added, wherein a timestamp of another timestamped data having a timestamp added after the timestamped data to be checked. The first to third hash values are sequentially stored in the target data management table. And a first step of confirming that the first to third hash values are correct, and a third hash value of the time-stamped data to be confirmed and a confirmation stored in the time stamp table. Determines whether the digital signature of the target time-stamped data matches, and if both match, counts the count value stored with the digital signature of the time-stamped data A second step of outputting as information indicating the acceptance time of the time stamp. 10. A time stamp generating apparatus for generating and outputting a time stamp indicating an order of accepting input data, comprising: first processing means for updating a counter value each time input data is accepted; Accepting, generating a digital signature of the input data and the count value of the counter using a previously registered signature key, and outputting the generated digital signature and the count value as a time stamp; A time stamp generating apparatus comprising: 11. A time stamp generating apparatus for generating and outputting a time stamp indicating a timing of receiving input data, comprising: first processing means for receiving input data and updating a count value of a counter; A second processing unit that generates a digital signature of the counter and the count value of the counter using a previously registered signature key, and outputs the generated digital signature and the count value as a time stamp; And a third processing unit for performing a predetermined process such that the process by the second processing unit is performed at a predetermined time interval. 12. The time stamp generation device according to claim 10, wherein the generation device is configured by an IC card having a storage function and an arithmetic function. 13. A system comprising: a time stamp generating device for receiving data and generating and managing a time stamp indicating an order of receiving the data; and a time stamp managing device, wherein the time stamp generating device converts the input data into First processing means for updating the count value of the counter each time it is accepted; and generating a digital signature of the received input data and the count value of the counter using a previously registered signature key. A second processing unit that outputs the count value as a time stamp, wherein the time stamp management apparatus further includes a first hash value of the time stamp addition target data and another time stamp addition target data added immediately before. Second
A third processing unit that generates a third hash value with the hash value, stores the third hash value in the target data management table in the order in which the time stamps are assigned, and outputs the stored third hash value as input data of the time stamp generation device. And a fourth processing means for storing a time stamp output from the time stamp generating device in a time stamp table. 14. A system comprising a time stamp generating device and a time stamp managing device for receiving data and generating and managing a time stamp indicating the receiving time of the data, wherein the time stamp generating device converts the input data into Receiving, first processing means for updating the count value of the counter at predetermined time intervals, and generating a digital signature of the received input data and the count value of the counter using a previously registered signature key, A second processing unit for outputting a digital signature and the count value as a time stamp, wherein the time stamp management device adds a first hash value of the data to be subjected to the time stamp and another time stamp added immediately before the first hash value. The second of the data to be granted
A third processing unit that generates a third hash value with the hash value, stores the third hash value in the target data management table in the order in which the time stamps are assigned, and outputs the stored third hash value as input data of the time stamp generation device. And a fourth processing means for storing a time stamp output from the time stamp generating device in a time stamp table. 15. The time stamp management device may sequentially determine first to third hash values of other time stamped data to which a time stamp has been added after the time stamped data to be checked. Acquired from the target data management table,
A fourth processing means for confirming that the third hash value is correct, a third hash value of the time-stamped data to be confirmed, and a time stamp to be confirmed stored in the time stamp table It is determined whether or not the digital signature of the time-stamped data matches with the digital signature of the time-stamped data. 15. The time stamp management system according to claim 13, further comprising: a fifth processing unit that outputs the time stamp.