| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent authentication information from being known by a third party, in authentication using an image as the authentication information. <P>SOLUTION: (a) is distribution authentication images GB11-GB13 to be distributed in a certain period, to a user to be authenticated, and (b) is distribution authentication images GB21-GB23 to be distributed in a period following it. In (a), a correct answer image including a characteristic of a "circle" as the authentication information and a dummy image including a characteristic different from it are disposed. A user in charge of authentication decides that the authentication succeeds when the characteristic of the "circle" is included in the distribution authentication image. Contents of the distribution authentication images provided to terminals are different from each other so as to make the correct answer image indistinguishable. When the authentication information of (a) is invalidated, an authentication image containing a correct answer image including a characteristic of a "heart shape" of (b) is distributed. The characteristic of the correct answer image is varied with time, thereby preventing the authentication information from being known by the third party. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
