| 摘要 |
<P>PROBLEM TO BE SOLVED: To distribute a content key inexpensively in safety in VOD service while preventing eavesdropping. <P>SOLUTION: In order to distribute a content key in safety, a limited receiving function introduced for digital CATV is used, and the content key is generated from two scramble keys being delivered by the limited receiving function according to a predetermined algorithm. Furthermore, the content key is encrypted by the scramble key and delivered as VOD information to a receiver where the content key is decrypted using a scramble key obtained by the limited receiving function. Consequently, the content key is distributed in safety. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
