| 摘要 |
PROBLEM TO BE SOLVED: To permit contents reproduction only once and to move them after recording them in a medium. SOLUTION: A recording and reproducing device is provided with: a ciphering means for ciphering, by each unit block, information in which a plurality of unit blocks are continued; a recording means for recording the ciphered information; and a deciphering means for deciphering and reproducing, by the unit block, the plurality of unit blocks of the ciphered information read from a recording medium. The seed of a cipher key for ciphering the unit block and the seed of the cipher key for deciphering the ciphered unit block are based on one or more unit blocks other than a prescribed unit block or the information for which one or more unit blocks other than the prescribed unit block are ciphered. In recording data ciphered by the method on the recording medium requiring driving, the cipher key or the seed of the cipher key is recorded in a memory attached to the recording medium. COPYRIGHT: (C)2003,JPO |
