Patent ID: 7748028

Claim:
An authentication method for performing user authentication processing on a user of a terminal device, the method comprising: transmitting, at the terminal device, first authentication information including a user ID to a relay device; forwarding, at the relay device, the first authentication information to an authentication server associated with the user ID; performing, at the authentication server, user authentication processing on the user of the terminal device, based on the first authentication information; issuing, at the authentication server, a temporary ID for the user of the terminal device and transmitting an authentication server ID for identifying the authentication server and the temporary ID to the relay device; communicating, at the relay device, the temporary ID and the authentication server ID to the terminal device; transmitting, at the terminal device, second authentication information including the temporary ID and the authentication server ID to the relay device; transmitting, at the relay device, third authentication information including the temporary ID to the authentication server, based on the authentication server ID included in the second authentication information; and performing, at the authentication server, user authentication processing on the user of the terminal device, based on the third authentication information.