| 摘要 |
PROBLEM TO BE SOLVED: To provide a biometric authentication system, authentication client terminal, and biometric authentication method to significantly reduce an expected value of the number of inputs of biometric data for authentication, while effectively preventing spoofing. SOLUTION: In a biometric authentication system 1, prior probabilities of enrolled users u<SB>n</SB>and non-enrolled users u<SB>0</SB>are set previously, and 1:N matching is performed between feature quantity data of a user to be authenticated v and matching feature quantity data. The matching score is calculated for each enrolled user u<SB>n</SB>. The ratio of the likelihood v=u<SB>n</SB>to the likelihood v≠u<SB>n</SB>is calculated for each enrolled user u<SB>n</SB>using the calculated matching scores. Posterior probabilities of the enrolled users u<SB>n</SB>and non-enrolled users u<SB>0</SB>are calculated, using the likelihood ratios, and the prior probabilities of both the enrolled users u<SB>n</SB>and the non-enrolled users u<SB>0</SB>. Then, determination is made by comparing each posterior probability with a first threshold. COPYRIGHT: (C)2010,JPO&INPIT |
