公开(公告)号：US07215770B2

公开(公告)日：2007-05-08

申请号：US10403834

申请日：2003-03-31

申请人： Leo M. Pedlow, Jr. ,  Henry Derovanessian ,  Brant Candelore

发明人： Leo M. Pedlow, Jr. ,  Henry Derovanessian ,  Brant Candelore

IPC分类号： H04L9/00 ,  H04N7/167

CPC分类号： H04N7/1675 ,  H04L9/08 ,  H04L63/0428 ,  H04L2209/60 ,  H04N21/23608 ,  H04N21/23897 ,  H04N21/43607

摘要： A multimedia stream head end includes a legacy conditional access (CA) device that fully encrypts the stream using legacy keys. A copy of the stream is sent to a secondary CA device that encrypts only critical packets in the stream using secondary keys to render a partially encrypted stream. The critical packets in the fully encrypted stream from the legacy CA device are obtained and inserted next to the corresponding critical packets in the partially encrypted stream. Thus, only critical packets are encrypted, with encrypted versions being generated by both the legacy CA and secondary CA without the legacy CA knowing which of the packets that it encrypts are “critical”.

摘要翻译： 多媒体流头端包括使用传统密钥完全加密流的传统条件访问（CA）设备。 流的副本被发送到辅助CA设备，其仅使用辅助密钥来加密流中的关键分组以呈现部分加密的流。 来自传统CA设备的完全加密的流中的关键分组被获取并插入在部分加密的流中相应的关键分组之后。 因此，只有关键数据包被加密，加密版本由传统CA和辅助CA生成，而传统CA知道其加密的哪个数据包是“关键的”。