SIGNATURE METHOD FOR PREVENTING FALSIFICATION OF REWRITABLE MEDIA, SIGNATURE APPARATUS FOR EXECUTING METHOD THEREOF, SIGNATURE SYSTEM FOR PREVENTING FALSIFICATION PROVIDED WITH THE APPARATUS, SIGNATURE PROGRAM FOR PREVENTING FALSIFICATION TO REALIZE METHOD THEREOF, AND COMPUTER-READABLE RECORDING MEDIUM WITH THE FALSIFICATION PREVENTING SIGNATURE PROGRAM RECORDED THEREON

摘要

PROBLEM TO BE SOLVED: To simply discriminate whether or not falsification exists in display data after authentication by a rewritable medium single body. SOLUTION: A falsification preventing signature apparatus includes: a feature quantity extract section 33 for extracting a feature quantity denoting a feature of image data according to an instruction of an authenticator authenticating display data; an encryption/decryption section 35 for generating encrypted data by using an encryption key in pairs with an identifier to encrypt the feature quantity and decrypting the encrypted data into the feature quantity; a media write section 34 for attaching the identifier and the encrypted data to the rewritable media; and a controller 37 for discriminating whether or not the decrypted feature quantity is coincident with a feature quantity extracted from image data that are read from the display data and generated. COPYRIGHT: (C)2004,JPO