Authentication apparatus, authentication method, authentication system, and recording medium

An authentication method executed by an authentication apparatus, the authentication method comprising:

• a biometric key generation step of generating a biometric key, when a first condition is satisfied, from biometric information of a user by means of a predetermined one-way function;
• a public key acquisition step of acquiring an information processing device public key from an information processing device;
• a pair key generation step of generating a pair key based on the biometric key and random information that is randomly generated information, the pair key including an authentication apparatus secret key and an authentication apparatus public key;
• a common key generation step of generating a common key based on the authentication apparatus secret key generated in the pair key generation step and the information processing device public key acquired in the public key acquisition step;
• an identification information generation step of generating, based on the random information and the common key generated in the common key generation step, identification information for verifying validity of the user;
• a determination instruction step of transmitting, to the information processing device, the identification information generated in the identification information generation step and the authentication apparatus public key generated in the pair key generation step and instructing the information processing device to verify validity of the user based on the identification information and the authentication apparatus public key;
• and
• an updating step of, when a second condition that is different from the first condition is satisfied, updating contents of the identification information in such a way as to be different from contents of the identification information generated in the identification information generation step.

An authentication system, comprising:

• an authentication apparatus;
• and
• an information processing device including information processing device pair key generation means for generating a pair key, the pair key including an information processing device public key and an information processing device secret key, the information processing device being configured to give an instruction to provide a service, wherein
• the authentication apparatus includes:
• biometric key generation means for, when a first condition is satisfied, generating a biometric key from biometric information of a user by means of a predetermined one-way function;
• public key acquisition means for acquiring, from the information processing device, the information processing device public key generated by the information processing device pair key generation means;
• authentication apparatus pair key generation means for generating a pair key based on the biometric key and random information that is randomly generated information, the pair key including an authentication apparatus secret key and an authentication apparatus public key;
• common key generation means for generating a common key based on the authentication apparatus secret key generated by the authentication apparatus pair key generation means and the information processing device public key acquired by the public key acquisition means;
• identification information generation means for generating, based on the random information and the common key generated by the common key generation means, identification information for verifying validity of the user;
• determination instruction means for transmitting, to the information processing device, the identification information generated by the identification information generation means and the authentication apparatus public key generated by the authentication apparatus pair key generation means and instructing the information processing device to verify validity of the user;
• and
• updating means for, when a second condition that is different from the first condition is satisfied, updating contents of the identification information in such a way as to be different from contents of the identification information generated by the identification information generation means, and
• the information processing device further includes:
• identification information and the like acquisition means for acquiring the identification information and the authentication apparatus public key transmitted by the determination instruction means;
• determination means for determining validity of the user based on the identification information and the authentication apparatus public key acquired by the identification information and the like acquisition means;
• and
• service provision instruction means for giving an instruction to provide a service for the user the validity of whom has been verified by the determination means.

A recording medium storing a program, the program causing a computer to function as:

• biometric key generation means for, when a first condition is satisfied, generating a biometric key from biometric information of a user by means of a predetermined one-way function;
• public key acquisition means for acquiring an information processing device public key from an information processing device;
• pair key generation means for generating a pair key based on the biometric key and random information that is randomly generated information, the pair key including an authentication apparatus secret key and an authentication apparatus public key;
• common key generation means for generating a common key based on the authentication apparatus secret key generated by the pair key generation means and the information processing device public key acquired by the public key acquisition means;
• identification information generation means for generating, based on the random information and the common key generated by the common key generation means, identification information for verifying validity of the user;
• determination instruction means for transmitting, to the information processing device, the identification information generated by the identification information generation means and the authentication apparatus public key generated by the pair key generation means and instructing the information processing device to verify validity of the user based on the identification information and the authentication apparatus public key;
• and
• updating means for, when a second condition that is different from the first condition is satisfied, updating contents of the identification information in such a way as to be different from contents of the identification information generated by the identification information generation means.