| 摘要 |
PROBLEM TO BE SOLVED: To provide a recording system of a disk shaped optical recording medium in which a recorded disk shaped optical recording medium is made as a parent, duplicates of the parent are successively made and grandchildren copies are made into totally nonsensical duplicates. SOLUTION: The digital recording device of information uses a disk shaped optical recording medium 14 having a read-only region and a programmable region. In the device, the positional relationship between a mark 24b, which is provided at least at one place on the medium 14, and the read-only signals from a read-only region 24, is made into key information to cipher input information and the ciphered information is recorded in the programmable region. |
