| 摘要 |
PROBLEM TO BE SOLVED: To provide a client with a service on the basis of a necessary certificate. SOLUTION: A client computer transmits user data to an authentication server, receives a certificate from the authentication server and stores the certificate. A service-providing method includes the steps of receiving a service request from the client computer, requesting the certificate corresponding to the requested server from the client computer, receiving the certificate from the client computer, deciding whether or not mutual authentication by another authentication server is enabled, in the case the authentication level of the received certificate does not satisfy an authentication the level necessary for the requested service, making a mutual authentication request to the other authentication server in the case the mutual authentication enabled, and providing the client computer with the service in the case the mutual authentication satisfies the authentication level. |
