Patent ID: 7448540

Claim:
An authentication apparatus for communicating with a first terminal and with a second terminal demanding to authenticate a user of the first terminal, and performing the authentication demanded by the second terminal, the apparatus comprising: a user database storing authentication information registered by a user of the first terminal; a first communication unit connecting to the first terminal via a first communication network, said first communication unit transmits to the first terminal an order to inquire said authentication information and receives from the first terminal an answer inputted by the first terminal corresponding to the order; a second communication unit connecting to the second terminal via a second communication network, said second communication unit receives from the second terminal an authentication demand to authenticate the user of the first terminal; and a processing unit performing the authentication, said processing unit sets up an identifying number to identify the authentication demanded by the second terminal, and when the first terminal transmits the same identifying number as said identifying number to said authentication apparatus, synchronizes a communication to the first terminal with a communication to the second terminal, retrieves from said user database authentication information to authenticate the user of the first terminal, and by inquiring the answer received from the first terminal with said authentication information retrieved from said user database, authenticates the user of the first terminal; wherein said second communication unit, by transmitting to the second terminal an authentication result judged by said processing unit, authenticates the user of the first terminal.