| 摘要 |
PROBLEM TO BE SOLVED: To improve versatility of a storing device by recording a contents key ciphered by a preservation key and contents data ciphered by the contents key in a recording medium, and decoding the contents key ciphered by a preservation key reproduced from the recording medium by the preservation key. SOLUTION: A recording and reproducing device 140 is provided with freely attachably and detachably a recording medium 141 exclusively used for electronic distribution being a data storing device. Then, the recording medium 141 exclusively used for electronic distribution holds an intrinsic preservation key in a storage module 201 of a cipher processing section 191. Then, the recording medium 141 exclusively used for electronic distribution ciphers the contents key by the preservation key when the contents key transmitted from the recording and reproducing device 140 is recorded in an external memory 193, also, when the ciphered contents key is desired to be reproduced, a reproduced contents key is decoded by the preservation key and transmitted tp the recording and reproducing device 140. |
