Biometric authentication system, communication terminal device, biometric authentication device, and biometric authentication method

A communication terminal apparatus used in a biometric authentication system comprising the communication terminal apparatus owned by a user subjected to biometric authentication and a biometric authentication apparatus that performs the biometric authentication, the communication terminal apparatus comprising:

• a registered information storing section that stores key information issued in association with biometric information at the time of registration of the user;
• a key concealment section that performs an exclusive OR operation of the stored key information and a first error correction code to calculate key concealment information and transmits the calculated key concealment information to the biometric authentication apparatus, the first error correction code being randomly selected from a predetermined error correction code group;
• an authentication parameter extracting section that acquires error corrected information calculated on the basis of an exclusive OR of biometric information at the time of authentication acquired by the biometric authentication apparatus when the user asks for the biometric authentication, the transmitted key concealment information, and a registration conversion template being the exclusive OR of the biometric information at the time of the registration, the key information and a second error correction code randomly selected from the error correction code group, and performs an exclusive OR operation of the acquired error corrected information and the first error correction code to calculate information to be verified;
• and
• a verification information generating section that generates information obtained by concealing the calculated information to be verified, as information for verification, and transmits the generated information for verification to the biometric authentication apparatus.

A biometric authentication apparatus used in a biometric authentication system comprising a communication terminal apparatus owned by a user subjected to biometric authentication and the biometric authentication apparatus that performs the biometric authentication, the biometric authentication apparatus comprising:

• an authentication biometric information acquiring section that acquires biometric information at the time of authentication from a person asking for biometric authentication;
• an authentication information acquiring section that acquires key concealment information from a communication terminal apparatus owned by the person;
• an error correction processing section that calculates error corrected information on the basis of an exclusive OR of the acquired biometric information at the time of the authentication, the acquired key concealment information, and a registration conversion template being an exclusive OR of the biometric information at the time of registration, key information issued in association with the biometric information at the time of the registration and a second error correction code randomly selected from an error correction code group;
• and
• a verification processing section that transmits the calculated error corrected information to the communication terminal apparatus, and performs the biometric authentication on the basis of the degree of identity between the information to be verified that is calculated by the communication terminal apparatus in response to the transmission and the second error correction code used to generate the registration conversion template.

A method of biometric authentication used in a biometric authentication system comprising a communication terminal apparatus owned by a user subjected to biometric authentication and a biometric authentication apparatus that performs the biometric authentication, the method of biometric authentication comprising:

• performing an exclusive OR operation of key information issued in association with biometric information at the time of registration of the user and a first error correction code to calculate key concealment information in the communication terminal apparatus, the first error correction code being randomly selected from a predetermined error correction code group;
• acquiring biometric information at the time of authentication from a person asking for biometric authentication, acquiring the key concealment information from the communication terminal apparatus owned by the person, and calculating error corrected information on the basis of an exclusive OR of the acquired biometric information at the time of the authentication, the acquired key concealment information, and a registration conversion template being the exclusive OR of the biometric information at the time of the registration, the key information and a second error correction code randomly selected from the error correction code group, in the biometric authentication apparatus;
• performing an exclusive OR operation of the error corrected information transmitted from the biometric authentication apparatus and the first error correction code to calculate information to be verified, and transmitting information for verification calculated from the information to be verified to the biometric authentication apparatus, in the communication terminal apparatus;
• and
• performing the biometric authentication on the basis of the degree of identity between the information for verification calculated on the basis of the transmitted error corrected information and the second error correction code used to calculate the error corrected information, in the biometric authentication apparatus.