Digital signature assurance system, method, program and apparatus

An digital signature generating apparatus, which is provided so as to be communicated to the user authentication apparatus for executing a user authentication in accordance with a user authentication system that has been set in advance upon receipt of a request of the user authentication;

• generating the first assertion for asserting the user authentication system when a result of this user authentication indicates validity;
• and outputting the result of the user authentication and the first assertion, the apparatus comprising:
• a key management device configured to manage an digital signature generation key in accordance with a key management system that has been set in advance for each generation request source of the digital signature;
• an authentication request transmission device configured to transmit a user authentication request for the generation request source of the digital signature to the user authentication apparatus upon receipt of the generation request of the digital signature;
• an digital signature generation device configured to generate the digital signature by using the corresponding digital signature generation key in the key management device when a result of this user authentication received from the user authentication apparatus indicates validity;
• a second assertion generation device configured to generate the second assertion for asserting the key management system;
• means for applying the conversion processing to the digital signature and the first and second assertion and relating the digital signature and the first and second assertion each other by the acquired conversion value;
• and
• an output device configured to output the digital signature, the first and second assertion, and the conversion value.