Patent ID: 8082213

Claim:
A user-authentication service implemented as routines that execute one or more computer systems interconnected by two or more communications media with both an authentication-service client, and a user, the user-authentication service comprising: the one or more computer systems; stored user-authentication policies specified by the user; stored user information; account interface routines that implement an account interface by which the user specifies, modifies, adds, and deletes user-authentication policies; and authentication-interface routines that implement an authentication interface by which, following initiation of a transaction by the user with the authentication-service client, the authentication-service client submits an authentication request, through the first communications medium or through a second communications medium, to authenticate the user, the authentication-interface routines employing a variable-factor authentication, when specified to do so by stored user-authentication policies, to authenticate the user on behalf of the authentication-service client during which the user communicates with the user-authentication service through a third communications medium different from the first and second communications media and a user device different from that employed by the user to initiate the transaction with the authentication-service client.