| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the transmission of recorded information to the Internet etc. against the intention of a creator, or make it hardly to use, even if the information is transmitted. <P>SOLUTION: Control information following the video audio information is provided with information about copy restriction and information about the propriety of transmitting video audio information via a communication line such as the Internet. When transmission-prohibited information is recorded in a recording medium, the information is encrypted using a device key and a content key. Thus, even the medium is detached and is attached to a personal computer to transmit the information, the information is difficult to be decrypted. <P>COPYRIGHT: (C)2007,JPO&INPIT |
