| 摘要 |
<p>PROBLEM TO BE SOLVED: To make it possible for a viewer to view 'copy-inhibited' contents only once when he/she desires. SOLUTION: The seed of a cryptographic key for enciphering a specified unit block is based on the cryptographic key used at the time of enciphering a block precedent to a specified block in the order of reproduction, and the head of the unit block is at least one of the GOP of MPEG video, a single audio frame of MPEG audio, a PES packet of an MPEG system layer, a TS packet group of the MPEG system layer, an information group recorded in a single track of a tape medium, an information group recorded in a single sector of a disk medium, and an information group recorded in an ECC block of media constituting the ECC.</p> |
