| 摘要 |
<p>An encryption arrangement for multiple encryption of TV programs. A system (100) according to embodiments of the present invention multiple encrypts only a portion of the data required for full presentation of a TV program to permit coexistence of multiple conditional access encryption systems (118, 124) associated with multiple manufacturer's set-top boxes (36, 136) within a single system. In one embodiment, a time slicing technique is used to encrypt portions of a program on a time allocated basis. By only encrypting a portion of the program, dramatically less bandwidth is consumed than the alternate of multiple encryption of all program data, thus permitting a larger number of programs to be carried over the same bandwidth while permitting coexistence of multiple conditional access systems in a single CATV system (32).</p> |
