| 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: An information digital recording device uses a disk shaped optical recording medium 14 which has a read-only region and a writable region. The positional relationship between a magnetic recording region 14m, which is provided at least at one place on the disk shaped optical recording medium, and the read-only signals from a read-only region 14a is made as key information to cipher inputted information and the ciphered input information is recorded into the writable region of the medium. |
