| 摘要 |
<p>A biometric authentication system, authentication client terminal, and biometric authentication method are provided to reduce an expected value of the number of inputs of biometric data for authentication, while effectively preventing forgery. In a biometric authentication system, prior probabilities of enrolled users (u n ) and non-enrolled user (u 0 ) are previously set. 1:N matching is performed between feature data of a claimant (v) and matching feature data. The matching score is calculated for each enrolled user (u n ). A ratio of the likelihood v=u n to the likelihood v‰ u n is calculated for each enrolled user (u n ) using the calculated matching scores. Posterior probabilities of the enrolled users (u n ) and non-enrolled user (u 0 ) are calculated, using the likelihood ratios, and the prior probabilities of both the enrolled users (u n ) and the non-enrolled user (u 0 ). Then, determination is made by comparing each posterior probability with a first threshold (A).</p> |
