| 摘要 |
PROBLEM TO BE SOLVED: To block the reception of an authentication certificate by an impersonator by collating communication records stored in both authentication server and client in the authentication server and/or the client in the case that an access request from the client is present. SOLUTION: At the time of passing the authentication of individual information between the authentication server 1 and the client 3, the authentication server 1 issues the authentication certificate to the client 3. Also, the present date and time and the number of times of communication are written in a storage device inside the client 3 and the same date and time and number of times of the communication are preserved and stored also in the storage device inside the authentication server 1. In the case that a normal user accesses the authentication server 1 for second and succeeding times, a normal password is used. The authentication server 1 confirms that a user ID and the password are normal and the communication log of a previous time preserved inside the client 3 matches with the one preserved inside the authentication server 1 and permits transition to an authentication processing. |
