| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To bring a public key certificate used for time certification information (time stamp) into one-to-one correspondence with electronic information. <P>SOLUTION: The time certification apparatus 20 receives the hash value of the electronic information together with a time stamp issuance request from a client apparatus 10 and requests an authentication station apparatus 30 to issue the public key certificate different for each received time stamp issuance request. The time certification apparatus 20 transmits a time stamp for which an electronic signature using a secret key paired with the public key of the public key certificate issued by the authentication station apparatus 30 according to the issuance request of the certificate is executed to information including the received hash value and time information, and the public key certificate to the client apparatus 10. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
