ENCRYPTION PROCESSING APPARATUS, ENCRYPTION PROCESSING METHOD, DECRYPTION PROCESSING APPARATUS, AND DECRYPTION PROCESSING METHOD

摘要

PROBLEM TO BE SOLVED: To surely prevent unauthorized copying.SOLUTION: Data encrypted by a 1394 interface 26 of a DVD player 1 is transmitted to a personal computer 2 and a magneto-optical disk device 3 via a 1394 bus 11. In the magneto-optical disk device 3 in which function modification is not released to a user, a 1394 interface 36 decrypts the received data. On the other hand, in the personal computer 2 in which the function modification is released to the user, a 1394 interface 49 decrypts the encrypted data by using time-varying key i, and an application unit 61 further decrypts decrypted result by using a session key S.