| 摘要 |
<p>In an electronic musical apparatus, a media ID (MD1, MD2, MD3, MD4, MD5) is associated with each recording media of a memory card 8, hard disk device 10, flash memory ROM 11, CD-ROM 12 and internet 15. Each media ID is encrypted to be recorded on a different position in a ROM 2. Upon reading a music content, the media ID of the corresponding recording media is decoded to decode the music content based upon the media ID and the secret key, and then, the resultant is temporarily stored in a RAM 3. Upon writing a music content, it is encrypted based upon the media ID corresponding to a recording media and the secret key, and the content in the RAM 3 is deleted. This makes cryptanalysis hard to thereby enhance a protection level of a music content in an electronic musical apparatus. <IMAGE></p> |
