To provide a security system capable of extracting a same/similar face image even if a face in authentication is varied from that in registration.

A camera device 1 having a face image input part 4 and an authentication server 2 are connected mutually via a communication line network 3. The authentication server 2 is provided with a face image acquisition part 6, an image storage part 11 storing face image data, a registration information generation part 8 cutting a face part around the eyes, the eyebrows, the nose of the face image, calculating a DCT coefficient, generating a binary one-dimensional template, and associating a face image data file name and the binary one-dimensional template by one-to-one correlation, and a database 9 storing a registration template. The authentication server 2 is also provided with an authentication part 7 calculating a DCT coefficient for the face image from the face image input part, comparing the DCT coefficient with the binary one-dimensional template, and extracting one or a plurality of registration templates matching the binary one-dimensional template having correlation above a threshold value and a display part 10 for displaying the registration template.