SIGNATURE DEVICE AND METHOD

摘要

PROBLEM TO BE SOLVED: To confirm the correctness of a signature without verifying a digital signature at the time of digitally signing information relating to the utilization of a source unutilizable without key information. SOLUTION: The connection calculation part 34 of a signature information issuance part 22 connects the utilization information of the source and ciphered key information by prescribed calculation and provides them to a user. On a user side, a signature calculation part 30 executes signature calculation by using an individual key to the entire connected information and returns an executed result to the separation calculation part 35 of the signature information issuance part 22. The separation calculation part 35 separates the signed connected information into the key information and the signed utilization information. The key information is used so as to cancel the protection of the source.