| 摘要 |
PROBLEM TO BE SOLVED: To enable a program provider to select a copy preventing function and to eliminate the necessity of a converter of a different format for a copy preventing function by using a field limited in a GA format. SOLUTION: The proposed copy preventing method is executed in an audio and video signal transmission process and a receiving and recording process. In the transmission process, a marker formed by a control word for scrambling an audio and video bit stream and by a copy preventing information for preventing illegal copy is used as a base. The marker is encrypted by using a encrypted key and multiplexed by the audio and video bit stream scrambled by the control word, and the multiplexed marker is transmitted. Thus the marker prepared by a program producer is multiplexed by the audio and video bit stream and transmitted. |
