DATA PROCESSING DEVICE

PROBLEM TO BE SOLVED: To provide a data processing device which can easily decode encoded data with one encoding key even if a person forgets another encoding key and reduce the storage capacity of a storage medium which stores encoded data in case that an encoding method is used which generates a plurality of encoded data from the same electronic data with different encoding keys. SOLUTION: A decryption code C1 is generated beforehand to an image data D1 to be encoded (or a duplicated image data generated based on the image data D1), and the image data D1 (or the identical duplicated image data of D1) is encoded with the decryption code C1. On the other hand, a compressed image data D2 generated based on the image data D1 to be encoded is encoded with another encoding key C2 (a user's ID code) different from the decryption code C1. COPYRIGHT: (C)2006,JPO&NCIPI