Verifier specified signature generation equipment, verifier specified signature system, program and the recording medium

摘要

PROBLEM TO BE SOLVED: To enable authentication for a third person that a person who makes a signature have made a verifier designation signature if that person wants it, while usually functioning as a verifier designation signature.;SOLUTION: A verifier designation signature generating apparatus 10 previously stores a secret value of the person who makes a signature into a secret value storage memory 11, and previously stores a secret key of the person and a public key of a signature verifier into a key storage memory 12. The apparatus 10 calculates a hash value of the secret value, and generates a verifier designation signature using at least the hash value, the secret key and the public key. The apparatus 10 transmits this secret key only in the case where it is authenticated for a person other than a specific signature verifier that the verifier designation signature has been made by this verifier designation signature generating apparatus. Further, a third person terminal device receives the verifier designation signature and the secret key, and uses the hash value of information including the secret value and the verifier designation signature to determine whether or not the person who has made the verifier designation signature is genuine.;COPYRIGHT: (C)2007,JPO&INPIT