JP2001155011A - Time identifying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for identifying time when distributing an encoded document processible for a computer through a computer network such as internet. SOLUTION: When distributing the encoded document processible for the computer through the computer network such as internet, a server system for identifying time is provided separately from two client systems on distributing and receiving sides. Thus, the time, when that sentence is prepared, can be certified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time authentication method suitable for creating an encoded document that can be processed by a computer and then guaranteeing the time when the document was created.

[0002]

2. Description of the Related Art Conventionally, there has been a method of using the contents certification system of a post office to prove the time when a certain document is created. On the other hand, for an encoded document that can be processed by a computer, there is a system that uses encryption technology to authenticate that the content of the document has not been tampered with and that the sender of the document is a specific person. Was. Reference 1: Tatsuaki Okamoto: "Cryptography and Information Security",
Nikkei BP, p. 172, 1998. Reference 2: Ei Yamaguchi: "Network Management (19) PK
What is I? ", UNIX MAGAZINE October, pp. 51-57, 1999.

[0003]

In this case, there is a drawback that the contents and the method of use are limited by the mail method. In a system that delivers an encoded document that can be processed by a computer by applying various encryption technologies, it is possible to authenticate that the content of the document has not been tampered with or that a specific person is the identity of the person. However, there was a disadvantage that the time could not be authenticated.

[0004]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve these problems by creating an encoded document which can be processed by a computer when transferring the document over a computer network such as the Internet. Then, after encrypting the document and the current time together, there is a time authentication function that allows the person who has the encrypted document to confirm the encrypted time. In order to achieve such an object, the present invention is characterized in that time authentication can be performed using a computer connected to a computer network.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a computer system which is an embodiment of a time authentication method according to the present invention. A client system (1) including an information transmission processing unit (4), an information processing unit with time (5), and an information processing unit (6); a specific time encryption processing unit (7); and a specific time decryption processing unit (8) ) And a computer network (3) connecting them. FIG. 2 shows a configuration of a computer network system which is an embodiment of the time authentication method according to the present invention. It comprises one or more client systems (1), a server system (2), and a computer network (3), which are computer systems having the configuration shown in FIG. FIG. 3 shows a detailed flow of operations of the two client systems (1) and the server system (2) in FIG. 2 when authenticating the time when a certain document is created. As shown in FIG. 3, first, in step 31 of the client system (1a), information of an encoded document that can be processed by a computer is sent to a server system. Next, in step 32 of the server system,
The transmitted information and the current time are encrypted together by a specific time encryption processing unit using a common key encryption method and transmitted to the client system (1a). Next, in step 33 of the client system (1a), the information encrypted in step 32 is received by the information processing unit with time, and sent to the client system (1b). Next, in step 34 of the client system (1b),
The information encrypted in step 32 is received by the information processing unit, and is sent to the server system after a lapse of a certain time. Next, in step 35 of the server system, the information encrypted in step 32 is decrypted by the specific time decryption processing section and sent to the client system (1b). Next, in step 36 of the client system (1b), the information before being encrypted in step 32 and step 3
The current time added in step 2 is received by the information processing unit. The client system (1) in step 31
a) transmitting and receiving information of the server system;
Server system and client system (1)
a) Transmission and reception of information, and the client system (1a) and client system (1b) in step 33
Transmission and reception of information of the client system (1b) and the server system in step 34,
In the transmission and reception of information between the server system and the client system (1b) in step 35, each information is transmitted and encrypted using the public key of the receiving side in the public key cryptosystem on the transmitting side, and the public key is transmitted on the receiving side. The effect of the present invention can be obtained by adding a process of decryption using a secret key on the receiving side in the encryption method.

[0006]

As can be seen from the embodiments described above, according to the present invention, when it is desired to certify the time at which a certain document was created, a method using a post office content certifying system is conventionally used. This has the disadvantage of taking time and limiting the form of target information. However, by using a method of authenticating time using a computer connected to a computer network, computers can be processed. For information encoded in, the time at which the information was created can be proved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a computer system showing an embodiment of the present invention.

FIG. 2 is a configuration diagram of a computer network system in which one or more client systems and one server system are connected via a computer network, showing an embodiment of the present invention.

FIG. 3 is a flowchart showing a detailed operation of the two client systems and one server system of FIG. 2 showing the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Client system 2 Server system 3 Computer network 4 Information transmission processing part 5 Information processing part with a time 6 Information processing part 7 Specific time encryption processing part 8 Specific time decryption processing part

Claims (1)

[Claims] An information transmission processing unit (4) for processing information encoded by a computer, a time information processing unit (5) for processing time information, and a time information processing unit (5) for processing time information. A client system (1) having information and an information processing unit (6) for processing information;
A specific time encryption processing unit (7) for encrypting this information together with the current time, and a specific time encryption processing unit (7)
In a system in which a server system (2) having a specific time decryption processing unit (8) for decrypting the information encrypted by
In the time authentication method, a time authentication method characterized by certifying the current time, which was encrypted together with the information, as the creation time of the information.