Biometric authentication method and system

A biometric authentication system comprising:

• a client including:
• a feature data extraction unit that extracts a feature data array for registration from biometric information of a registration applicant at a biometric information registration time and extracts a feature data array for authentication from biometric information of a user at a authentication time;
• a conversion-parameter-for-comparison generation unit that generates a first conversion parameter for comparison by converting the feature data array for registration at the registration time and generates a second conversion parameter for comparison by converting the feature data array for authentication at the authentication time;
• a conversion-parameter-for-position-correction generation unit that generates a position correction template by converting the feature data array for registration at the registration time;
• a feature-data-conversion-for-position-correction unit that generates converted feature data for position correction from the feature data array for authentication at the authentication time;
• and
• a feature-data-conversion-for-comparison unit that generates a comparison template by converting the feature data array for registration using the first conversion parameter for comparison at the registration time, generates a corrected feature data array by performing position correction on the feature data array for authentication on the basis of a position correction amount at the authentication time, and generates a converted feature data array for comparison by converting the corrected feature data array using the second conversion parameter for comparison;
• and
• a server coupled with the client, the server configured to store the position correction template and the comparison template in a database coupled to the server, and further including:
• a position correction amount calculation unit that calculates the position correction amount between the feature data array for registration and the feature data array for authentication using the position correction template and the converted feature data for position correction;
• and
• a comparison and determination unit that calculates a distance between the comparison template and the converted feature data array for comparison and determines success or failure of authentication of the user as the registration applicant on the basis of comparison between the distance and a predetermined authentication threshold,
• wherein the generation of the position correction template by the feature-data-conversion-for-position-correction unit includes generating a local feature data array for registration by cutting a part of the feature data array for registration,
• wherein the generation of the converted feature data for position correction by the feature-data-conversion-for-position-correction unit includes generating a partial feature data array for authentication by cutting a part of the feature data array for authentication,
• wherein in the calculation of the position correction amount by the position correction amount calculation unit, a distance is calculated while the partial feature data array for authentication is repeatedly shifted relative to the local feature data array for registration, and a shift amount with which the distance is minimized is defined as the position correction amount, and
• wherein in the generation of the corrected feature data array, the feature data array for authentication is shifted by the position correction amount.

A biometric authentication system comprising:

• a registration client including:
• a first feature data extraction unit that extracts a feature data array for registration from biometric information of a registration applicant at a biometric information registration time;
• a first conversion-parameter-for-comparison generation unit that generates a first conversion parameter for comparison, the first conversion parameter for comparison being used to convert the feature data array for registration;
• a conversion-parameter-for-position-correction generation unit that generates a position correction template by converting the feature data array for registration;
• and
• a first feature-data-conversion-for-comparison unit that generates a comparison template by converting the feature data array for registration using the first conversion parameter for comparison;
• an authentication client including:
• a second feature data extraction unit that extracts a feature data array for authentication from biometric information of a user at an authentication time;
• a second conversion-parameter-for-comparison generation unit that generates a second conversion parameter for comparison, the second conversion parameter for comparison being used to convert the feature data array for authentication;
• a feature-data-conversion-for-position-correction unit that generates converted feature data for position correction from the feature data array for authentication;
• and
• a second feature-data-conversion-for-comparison unit that generates a corrected feature data array by performing position correction on the feature data array for authentication on the basis of the position correction amount and generates a converted feature data array for comparison by converting the corrected feature data array using the second conversion parameter for comparison;
• and
• a server coupled with the registration and authentication clients, the server configured to store the position correction template and the comparison template in a database coupled to the server and further including:
• a position correction amount calculation unit that calculates the position correction amount between the feature data array for registration and the feature data array for authentication using the position correction template and the converted feature data for position correction;
• and
• comparison and determination unit that calculates a distance between the comparison template and the converted feature data array for comparison and determines success or failure of authentication of the user as the registration applicant on the basis of comparison between the distance and a predetermined authentication threshold,
• wherein the generation of the position correction template by the feature-data-conversion-for-position-correction unit includes generating a local feature data array for registration by cutting a part of the feature data array for registration,
• wherein the generation of the converted feature data for position correction by the feature-data-conversion-for-position-correction unit includes generating a partial feature data array for authentication by cutting a part of the feature data array for authentication,
• wherein in the calculation of the position correction amount by the position correction amount calculation unit, a distance is calculated while the partial feature data array for authentication is repeatedly shifted relative to the local feature data array for registration, and a shift amount with which the distance is minimized is defined as the position correction amount, and
• wherein in the generation of the corrected feature data array, the feature data array for authentication is shifted by the position correction amount.