| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To check illegal use of digital data and to improve reliability even in the case of a system such as a personal computer. <P>SOLUTION: A DVD player 40 includes a drive part 50 for reading out recorded contents from a disk 30 in which digital data encrypted on the basis of a medium key K<SB>M</SB>and first to third key management information data composed of multiplexedly encrypting the medium key K<SB>M</SB>on the basis of a plurality of keys are recorded and a host part 60 for obtaining the medium key K<SB>M</SB>on the basis of the read contents of the drive part 50. The DVD player 40 manages a drive key KD<SB>j</SB>necessary for decrypting the medium key K<SB>M</SB>, a manufacturer key Km<SB>k</SB>and a host key KH<SB>i</SB>by dividing these keys into the DVD drive 50 with hardware configuration and the host 60 with software configuration. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
