AUTHENTICATION METHOD OF AUTHENTICATING MEDIUM HAVING IDENTIFICATION INFORMATION AND AUTHENTICATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an authentication method and authentication device that authenticate a medium using an artifact metrics whose duplication or forgery is difficult.SOLUTION: An authentication method comprises: a process of acquiring a preliminarily registered reference partial image; a photographing process of photographing a part of an image provided in a medium, and obtaining an authentication partial image; and a determination process of collating the reference partial image with the authentication partial image, and determining whether the image provided in the medium matches a regular image. The regular image has a plurality of regular unit areas including a characteristic peculiar to print. The reference partial image is photographed at first resolving power set so that at least one regular unit area appears distinguishably in the reference partial image, and further the photographing process is implemented at second resolving power set so that a unit area corresponding to the regular unit area appears distinguishably in the authentication partial image.SELECTED DRAWING: Figure 4