Long-term signature server, long-term signature terminal, and long-term signature verification server

A long-term signature terminal comprising:

• electronic signature means for electronically signing using a private key;
• public key certificate transmission means for transmitting to a long-term signature server a public key certificate of a public key corresponding to the private key;
• function value transmission means for transmitting to the long-term signature server a function value calculated from original data using a predetermined function;
• signature data reception means for receiving from the long-term signature server signature data for electronically signing the signing target data generated using the transmitted public key certificate and function value;
• and
• signature value transmission means for electronically signing the signing target data by the electronic signature means using the received signature data and for transmitting an electronic signature value from the electronic signature to the long-term signature server.

A computer-readable medium storing a long-term signature verification program having instructions for causing a computer to realize:

• an electronic signature function which electronically signs using a private key;
• a public key certificate transmission function which transmits a public key certificate of a public key corresponding to the private key to the long-term signature server;
• a function value transmission function which transmits to the long-term signature server a function value calculated from the original data using a predetermined function to;
• a signature data reception function which receives from the long-term signature server signature data for electronically signing the signing target data generated using the transmitted public key certificate and function value;
• and
• a signature value transmission function which electronically signs the signing target data by the electronic signature function using the received signature data and which transmits an electronic signature value from the electronic signature to the long-term signature server.