Patent ID: 8875270

Claim:
An ID authentication system comprising a terminal apparatus, a plurality of service providing apparatuses, and an authentication server, wherein the terminal apparatus comprises: a one-time ID generator for generating a one-time ID that is temporarily used; a one-time ID transmitter for transmitting the one-time ID generated by the one-time ID generator to one of the service providing apparatus; and a user ID transmitter for transmitting the one-time ID transmitted by the one-time ID transmitter and a user ID uniquely identifying a user to the authentication server, the service providing apparatus comprises an ID inquiry unit for receiving the one-time ID transmitted from the terminal apparatus and inquiring of the authentication server about authentication information corresponding to the one-time ID that receives, the authentication server comprises: an authentication information manager for storing a user ID in association with the authentication information to perform authentication in the service providing apparatus; an ID receiver for receiving the one-time ID and the user ID transmitted from the terminal apparatus; and a server ID response unit for acquiring the user ID corresponding to the one-time ID included in the inquiry from the service providing apparatus from the one-time ID and the user ID received by the ID receiver, and further acquiring the authentication information associated with the user ID in the authentication information manager based on the user ID that is acquired, to transmit the authentication information to the service providing apparatus, the one-time ID generator of the terminal apparatus generates the one-time ID including address information of the authentication server, the service providing apparatus makes an inquiry at the authentication server specified by the address information included in the one-time ID, and the one-time ID also includes a character string and a domain name which are temporal identification information.