| 摘要 |
PROBLEM TO BE SOLVED: To provide an authentication system which enables answering to an image that is presented for authentication by easier operation, capable of preventing access by a computer program with higher probability.SOLUTION: An authentication system includes a terminal and an authentication server. The terminal includes display control means allowing display of an authentication image generated by applying deformation to an image available by cutting out a basic diagram image that contains a plurality of diagram images by using a recognition target image, image deformation control means capable of varying the degree of deformation of the authentication image, and terminal communication control means for transmitting the deformation degree information on the displayed authentication image to an authentication server. The authentication server includes deformation degree determination means which compares the received deformation degree information with the information on deformation degree of the authentication information that makes the recognition target image visible, for determining whether or not the authentication image of the received deformation degree is in the deformation degree that makes the recognition target image visible, and authorization means which authenticates the terminal in a case where a true determination has been made. |
