Patent ID: 8595816

Claim:
A user authentication system which performs user authentication utilizing a terminal certificate between a user authentication apparatus and a user terminal, the system comprising: at least one user terminal having a certification authority secret key and a certification authority identifier, and at least one user authentication apparatus having a certification authority public key and a certification authority identifier are connected to at least a network, the user terminal includes: terminal certificate generation means which is configured to calculate a terminal signature using the certification authority secret key for signature subject information which is discretionary data, and generate a terminal certificate which is a self-signed certificate containing at least the signature subject information, the terminal signature, and the certification authority identifier; terminal information storage means which is configured to save the terminal certificate; registration request means which is configured to transmit at least the terminal certificate as a user registration request to the user authentication apparatus; and service request means which is configured to acquire from the terminal information storage means a terminal certificate corresponding to a certification authority identifier received from a user authentication apparatus upon a service request, and transmit the terminal certificate to the user authentication apparatus; and the user authentication apparatus includes: authentication information storage means; user registration means which is configured to register in the authentication information storage means a terminal certificate received from a user terminal; and user authentication means which is configured to transmit, in response to a service request from a user terminal when authenticating the user terminal, the certification authority identifier to the user terminal, obtain a corresponding terminal certificate from the user terminal, and verify the terminal signature contained in the terminal certificate using the certification authority public key.