| 摘要 |
<P>PROBLEM TO BE SOLVED: To create long-term signature data/signature data on the server side while a secret key and original data are not transferred to the server side. <P>SOLUTION: A terminal transmits a function value calculated from the original data using a predetermined function and a signature data of the original data (a signature value obtained by enciphering the function value of the original data using the secret key, and a public key certificate of a public key which corresponds to the private key). The server deciphers the signature value with the public key to take out a function value and compares the taken out function value and the function value transmitted from the terminal to determine the validity of the original data. If being a long-term signature, the server creates, using information constituting the signature data, information obtained by removing the original data from information for creating a function value for checking the long-term signature, and transmits the information to the terminal. The terminal adds the information to the original data to calculate a function value using the predetermined function, and transmits the function value to the server. The server verifies the validity of the long-term signature using the function value. <P>COPYRIGHT: (C)2013,JPO&INPIT |
