Patent ID: 7950050

Claim:
An authentication system comprising: a first information processor; a second information processor; an authentication-service-providing device; and an authentication device; said second information processor including, a second authentication information transmission unit that transmits second authentication information for authenticating a user to the authentication-service-providing device, and an authentication information obtaining unit that obtains third authentication information issued by the authentication-service-providing device in response to the second authentication information; said authentication-service-providing device including, a second authentication unit that receives the second authentication information from the second information processor and executes a second authentication based on the second authentication information, and an authentication information issuance unit that issues the third authentication information to the second information processor when the second authentication is successful; said first information processor including, a first authentication information transmission unit that receives input of first authentication information for authenticating the user and transmits the first authentication information to the authentication device, and a third authentication information transmission unit that receives input of third authentication information obtained by the second information processor and transmits the third authentication information to the authentication device; said authentication device including, a first authentication unit that receives the first authentication information from the first information processor and executes a first authentication based on the first authentication information, and a third authentication result obtaining unit that receives the third authentication information from the first information processor and cooperates with the authentication-service-providing device to obtain a result of a third authentication based on the third authentication information.