This invention relates to a biometric authentication system, and more particularly, to registration of a biometric certificate generated from biometric information.
A biometric authentication system performs personal authentication based on biometric information such as a fingerprint, a vein, an iris, a face, voice, and handwriting. Those pieces of biometric information are private information to be handled with care, and it is therefore required to manage the information properly to prevent leakage of the information. Further, the biometric authentication is expected to be widely used as social infrastructure from now on, but in order to use a large number of biometric authentication systems, it is required to register biometric information with each system. Thus, the user's time and effort to register the information is a factor that inhibits the widespread use of the biometric authentication systems.
JP 2013-123142 A is known as a technology for solving those problems. JP 2013-123142 A has the following description: “At the time of registration, a biometric signature system embeds a predetermined secret key into a feature quantity of biometric information on a user, and issues a biometric certificate containing a set of the feature quantity and a corresponding public key. At the time of signature, the biometric signature system newly generates a pair of a temporary secret key and a temporary public key for a signature feature quantity of biometric information on the user, creates a signature for a message through use of the temporary secret key, creates a commitment by embedding the temporary secret key into the signature feature quantity, and sets a set of the temporary public key, the signature, and the commitment as a biometric signature. At the time of verification of the biometric signature, the biometric signature system verifies the signature based on the temporary public key, and generates a difference secret key and a difference public key from the biometric certificate, the commitment, and the temporary public key to verify their correspondence.”