AUTHENTICATION COLLABORATION SYSTEM AND AUTHENTICATION COLLABORATION METHOD

An authentication collaboration server of an authentication collaboration system performs a secrecy calculation process using authentication information as input for an authentication process, generating secret authentication information for each piece of the authentication information. An authentication information verification server obtains and compares sets of the combination of secret authentication information generated by the authentication server, and a user ID identifying a user of a user terminal using the authentication information that is a source of the secret authentication information. The authentication information verification server extracts the plurality of pieces of authentication information that have been applied. The authentication collaboration server approves a service, when a user authentication state is removed as authentication results constituting the user authentication state satisfies the policy for the service, after an authentication result in which application of the authentication information has occurred. A collaboration service is achieved including multiple low cost Web services.