Time-multiplexed multi-program encryption system
First Claim
1. A system for time-multiplexed, multi-program encryption, comprising:
- at least one receiver for receiving and decoding at least one multiplex stream containing one or more programs;
critical packet identification means for identifying selected packets of said at least one multiplex stream to be encrypted;
at least one conditional access unit for encrypting selected packets of said at least one multiplex stream;
at least one multiplexer for directing said selected packets to said at least one conditional access unit for encryption, receiving said selected encrypted packets from said at least one conditional access unit and combining said selected encrypted packets and unencrypted packets into one or more output streams;
means for overriding and restoring parameters of said selected packets; and
wherein said unencrypted packets in said at least one multiplex stream are replaced with said selected encrypted packets corresponding to said unencrypted packets.
9 Assignments
0 Petitions
Accused Products
Abstract
A system and method are described for greatly increasing the number of services that can be encrypted with existing conditional access equipment. The method is most useful when many digitally compressed programs are encrypted at the same time. Only the most critical components of each compressed video, audio, or data stream are selected and then sequenced into a single stream. Additional formatting causes this sequence of segments from multiple sources to appear as a single continuous stream to the conditional access system. Once this stream has been encrypted, it is demultiplexed and the components are restored and re-sequenced into their respective programs. Messages such as the Entitlement Control Messages that are inserted into the stream by the encryption system, are also adjusted and included with each of the reconstructed programs. The technique not only allows encryption systems to be designed using less encryption hardware, but also simplifies the management of encryption sessions, particularly in on-demand programming applications.
84 Citations
20 Claims
-
1. A system for time-multiplexed, multi-program encryption, comprising:
-
at least one receiver for receiving and decoding at least one multiplex stream containing one or more programs; critical packet identification means for identifying selected packets of said at least one multiplex stream to be encrypted; at least one conditional access unit for encrypting selected packets of said at least one multiplex stream; at least one multiplexer for directing said selected packets to said at least one conditional access unit for encryption, receiving said selected encrypted packets from said at least one conditional access unit and combining said selected encrypted packets and unencrypted packets into one or more output streams; means for overriding and restoring parameters of said selected packets; and wherein said unencrypted packets in said at least one multiplex stream are replaced with said selected encrypted packets corresponding to said unencrypted packets. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A method for time-multiplexed, multi-program encryption, comprising:
-
receiving and processing streams corresponding to multiple programs; selecting critical packets from the multiple programs and combining them into at least one encryption stream; providing said encryption stream to a conditional access unit for encryption, said conditional access unit producing a corresponding encrypted stream; and separating packets in said encrypted stream and replacing corresponding packets of said multiple programs with said encrypted packets. - View Dependent Claims (15, 16)
-
-
17. A method for time-multiplexed, multi-program encryption, comprising:
-
receiving and processing streams corresponding to multiple programs; selecting and tagging critical packets from the multiple programs and combining them into at least one encryption stream; providing said encryption stream to a conditional access unit for encryption, said conditional access unit producing a corresponding encrypted stream; separating packets in said encrypted stream according to tag values and replacing corresponding packets of said multiple programs with said encrypted packets; for at least one encryption tier, monitoring a critical packet generation rate and generating an indication thereof; and transitioning programs from one encryption channel to another in response to said packet generation rate indication. - View Dependent Claims (18, 19, 20)
-
Specification