Patent ID: 8341696

Claim:
An image forming apparatus, comprising: an authentication information unit including login information indicating whether a user is logged into the image forming apparatus and an authentication key used to obtain the login information; an authentication key providing unit including the authentication key; a plurality of functional units implementing functions of the image forming apparatus; and a functional-unit authentication unit including authentication information indicating whether each of the functional units is authenticated and a first verification unit configured to determine whether one of the functional units is authenticated based on the authentication information; wherein each of the functional units includes an authentication key obtaining unit configured to obtain the authentication key from the authentication key providing unit when the first verification unit determines that said one of the functional units is authenticated; and the authentication information unit further includes a second verification unit configured to determine whether the authentication key obtained by the authentication key obtaining unit of said one of the functional units matches the authentication key included in the authentication information unit, and a login information providing unit configured to provide the login information to said one of the functional units when the second verification unit determines that the authentication key obtained by the authentication key obtaining unit of said one of the functional units matches the authentication key included in the authentication information unit.