Biometric authentication system, biometric authentication server, method and program thereof

A authentication server computer configured to store a plurality of pieces of biometric data, that is coupled to a plurality of client computers through a network, and processes an authentication request by checking biometric data for verification collected from a user of a client against the biometric data when the user requests the authentication through a client of the computer;

• the authentication server computer comprising:
• one or more computing machines configured to
• determine a cache target user, wherein the cache target user is another user who is different from the user who requested the authentication to the authentication server computer;
• generate an identifier of the cache target user;
• transmit biometric data of the cache target user and the identifier to the client computer of the user that requested the authentication;
• determine whether biometric data of any cache target user with a corresponding identifier are available on any of the client computers;
• measure a number of client computers that performed an authentication request to the authentication server computer;
• and
• determine the cache target user when the number of client computers measured by the measurement unit exceeds a certain number of client computers.

A biometric authentication method executed by an authentication server computer that includes a storage unit configured to store a plurality of pieces of biometric data, is coupled to a plurality of client computers through a network, and performs authentication request processing for a user of a client by checking biometric data for verification collected from a user against the biometric data, the method comprising:

• determining by the authentication server computer a cache target user, wherein the cache target user is another user who is different from the user who performed the authentication request to the authentication server computer;
• generating an identifier for the cache target user;
• transmitting by the authentication server computer biometric data of the cache target user and the identifier to the client computer of the user that performed the authentication request to the authentication server computer;
• measuring a number of client computers that performed an authentication request to the authentication server;
• and
• determining the cache target user when the number of client computers measured by the measurement unit exceeds a certain number of client computers.