COPYRIGHT PROTECTION SYSTEM, RECORDING DEVICE AND DECRYPTION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a copyright protection system capable of reproducing only original recording media by checking whether the recording media are original recording media or copy recording media. SOLUTION: A number unique to a medium is recorded on a recording medium 20 in an unrewritable state. A recording device 10 writes an encrypted content, an encrypted content key used to decrypt the encrypted content, and license information generated by reflecting both the encrypted content key and the unique media number on the recording medium 20. A reproduction device 30 acquires the unique media number, the encrypted content key and the license information recorded on the recording medium 20, judges whether the license information reflects both the unique media number and the encrypted content key. Only if the license information reflects both the unique media number and the encrypted content key, the reproduction device 30 decrypts the encrypted content key recorded on the recording medium 20, and decrypts the encrypted content by using the decrypted content key.