The present invention relates to an authentication apparatus and an authentication method, and a storage medium using the processing of matching blood vessel images (vein information) for authentication. The authentication apparatus capable of authenticating/matching images with a high precision comprises an acquisition section (11) for acquiring an image, a Hough transforming section (12) for transforming the image to information transformed with Hough transformation, vein information acquisition section (11) for acquiring proper vein information transformed with Hough transformation, matching section (16, 164) for matching the information with the proper vein information, and an authentication section (16, 17) for authenticating the acquired image according to a result of the matching section.