REPRODUCING APPARATUS AND REPRODUCING METHOD FOR REPRODUCING CONTENTS, PROGRAM, KEY MANAGEMENT APPARATUS AND KEY MANAGEMENT SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide technology with which only a legal reproducing apparatus is capable of properly reproducing contents by eliminating the reproduction of the contents by an illegal reproducing apparatus. SOLUTION: The reproducing apparatus holds a secret key (904), acquires encrypted key information encrypted by a secret key encryption system (902, 903) and uses the secret key for decrypting the encrypted key information to obtain key information (905). When the key information is key updating information, the secret key is updated on the basis of the key updating information (914). When the key information is a decryption key, an encrypted content key encrypted by the private key encryption system is acquired, the decryption key is used for decoding to obtain a content key (910), contents scrambled by a scramble encryption system are acquired, and the content key is used for descrambling (913) to reproduce the contents (913). COPYRIGHT: (C)2004,JPO&NCIPI