A system and method for using a single-use password to add SSO functionality to a service of a Service Provider belonging to an F-SSO federation that does not support F-SSO functionality for the service. In response to receiving notification from an Identity Provider that a user has requested access to the service, the Service Provider uses information provided by the Identity Provider to identify and authenticate the user, and then uses standard API calls to create and send a temporary password to the user. This password may be created as a function of the user's physical location or IP address and may be communicated out-of-band. Upon determining that the user has correctly returned the temporary password to the Service Provider, the Service Provider generates and sends the user a strong single-use password through a secure in-band communication, through which the user may access the service.