DIGITAL SIGNATURE METHOD IN SIGNER APPARATUS, DIGITAL SIGNATURE METHOD IN THIRD TRUSTED PARTY AGENCY APPARATUS, METHOD FOR DISCRIMINATING GENUINENESS OF DIGITAL SIGNATURE, SIGNER APPARATUS, THIRD TRUSTED PARTY AGENCY APPARATUS, APPARATUS FOR DISCRIMINATING GENUINENESS OF DIGITAL SIGNATURE, DIGITAL SIGNATURE PROGRAM FOR SIGNER APPARATUS, DIGITAL SIGNATURE PROGRAM FOR THIRD TRUSTED PARTY AGENCY APPARATUS, PROGRAM FOR DISCRIMINATING GENUINENESS OF DIGITAL SIGNATURE, AND PROGRAM RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a digital signature technique capable of discriminating whether a digital signature is a legitimate digital signature signed by an original possessor of a private key of the digital signature or a person other than the original possessor of the privacy key falsifies the digital signature by illegitimately acquiring the private key or other means when the digital signature is signed. SOLUTION: A system related to the first embodiment includes: a private key generating function for a digital signature whereby a private key for generating the digital signature can be separately stored between the original possessor of the private key and one third trusted party agency or more; a signature generating function whereby the digital signature can be generated only when the possessor of storing part of the private key and all the third trusted party agencies take part in generation of the signature; and a discriminating function of discriminating an illegitimate act when the digital signature is signed by an illegitimate method. COPYRIGHT: (C)2004,JPO&NCIPI