| 摘要 |
PROBLEM TO BE SOLVED: To permit a viewer to view contents only once at time when the viewer desires to view on the contents of 'No copy'. SOLUTION: The seed of a password key for ciphering a prescribed unit block is based on one or a plurality of unit blocks except for a prescribed unit block or information obtained by ciphering one or a plurality of unit blocks except for the prescribed unit block. The head of the unit block is at least one of GOP of an MPEG video, one audio frame of an MPEG audio, the PES packet of an MPEG system layer, the TS packet group of the MPEG system layer, an information group recorded in one track of a tape medium, an information group recorded in one sector of a disk medium and an information group recorded in the ECC block of a medium constituting ECC. |
