| 摘要 |
<p>A user authentication judging device stores proper environment information that is found proper as a use environment in an information processing device and also stores a proper environment judging threshold value set for every proper environment information. When the user authentication judging device detects that the use environment of the information processing device is changed, the user authentication judging device collects the changed environment information. If the changed environment information is consistent with any of the proper environment information, the user authentication judging device judges the authentication of the proper environment information. When the changed environment information is not consistent with any of the proper environment information, the user authentication judging device does not judge the authentication of the proper environment information. In the case where the changed environment information is authenticated, the user authentication judging device is instructed to receive living body information from applicants and also to set the proper environment judging threshold corresponding to the proper environment information that is consistent with the changed environment information to a similarity comparison subject to be calculated by checking. When receiving the living body information from the applicants, the user authentication judging device carries out a comparison of the living body information received from the applicants with registered living body information and its authenticating judgment by using the proper environment judging threshold instructed to set as the similarity comparison subject.</p> |
