| 摘要 |
The present invention enhances security in relation to biometric information distribution in a biometric signature system for generating a signature for an electronic document using biometric information as a private key. At the time of registration, commitment information for registration is generated by expanding a prescribed private key and embedding the key in a feature quantity for user biometric information, and the commitment information is disclosed as a set with a corresponding public key. At the time of signing, a new temporary private key and temporary public key pair for the user-biometric-information feature quantity for signing are generated, a signature for a message is generated using the temporary private key, a commitment for signing is generated by expanding the temporary private key and embedding the key in the feature quantity for signing, and a set of the temporary public key, signature, and commitment are output as a biometric signature. When the biometric signature is verified, the signature is verified using the temporary public key, error correction is performed for the difference between the commitment for registration and the commitment for signing, a differential private key is calculated through compression, and the correspondence between the differential private key, temporary public key, and public key is verified. |
