AUTHENTICATION SYSTEM AND AUTHENTICATION METHOD

PROBLEM TO BE SOLVED: To ensure security of a device without making an authorized user conscious of authentication processing. SOLUTION: A cellular phone 1a includes: a storage part 14 previously storing authentication information about a face image of a user; a casing status monitoring part 11 detecting a predetermined status of its own machine; an application monitoring part 12; an acquisition part 13 acquiring the face image of the user without notifying the user when a predetermined status is detected; a determination part 15 comparing the obtained face image with authentication information stored in the storage part 14 and determining whether agreement is obtained between them; and a function control part 16 maintaining a released condition when it is determined that the face image agrees with the authentication information since locking of a predetermined application is released before determination by the determination part 15, and when the face image does not agree with the authentication information, locking the predetermined function. COPYRIGHT: (C)2011,JPO&INPIT