Just in time delivery of entitlement control message (ECMs) and other essential data elements for television programming
First Claim
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1. A method of generating an encrypted transport stream, comprising:
- encoding at least one program into a compressed video stream;
coding random access points (RAPs) into the compressed video stream at which a decoder can begin decoding each said program;
detecting the occurrence of RAPs in the video stream;
generating encryption keys;
upon detecting the occurrence of a RAP in the video stream, triggering an ECM generator to generate an entitlement control message (ECM) based on the current encryption key, said ECM including a message that allows the decoder to derive the current encryption key needed to decrypt the associated video stream;
delaying the video stream to insert the ECM into the video stream just ahead of the detected RAP, said pairing of the ECM with the RAP allows the decoder to derive from the ECM the current encryption key needed to decrypt the associated video stream just in time to begin decoding the compressed video stream at the RAP; and
encrypting the video stream with a crypto codeword appropriate to the associated ECM to provide an encrypted transport stream.
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Abstract
Essential data elements, particularly entitlement control messages (ECMs), are inserted in a manner that reduces the overhead bit rate without effecting overall tuning time at the customer receiver or security in satellite, cable or other programming networks. ECMs are inserted into the transport stream by detecting random access points (RAPS) in the encoded programming and inserting the ECM packets in a window just ahead of the RAP.
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Citations
27 Claims
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1. A method of generating an encrypted transport stream, comprising:
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encoding at least one program into a compressed video stream; coding random access points (RAPs) into the compressed video stream at which a decoder can begin decoding each said program; detecting the occurrence of RAPs in the video stream; generating encryption keys; upon detecting the occurrence of a RAP in the video stream, triggering an ECM generator to generate an entitlement control message (ECM) based on the current encryption key, said ECM including a message that allows the decoder to derive the current encryption key needed to decrypt the associated video stream; delaying the video stream to insert the ECM into the video stream just ahead of the detected RAP, said pairing of the ECM with the RAP allows the decoder to derive from the ECM the current encryption key needed to decrypt the associated video stream just in time to begin decoding the compressed video stream at the RAP; and encrypting the video stream with a crypto codeword appropriate to the associated ECM to provide an encrypted transport stream. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. An apparatus, comprising:
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an encoder that encodes a program into a compressed video stream including random access points (RAPs) at which a decoder may begin decoding said compressed video stream; a detector that detects the occurrence of RAPs in said compressed video stream; a codeword generator that provides encryption keys; an entitlement control message (ECM) generator that upon the detection of an occurrence of a RAP triggers the generation of an ECM based on the current encryption key, said ECM including a message that allows the decoder to derive the current encryption key needed to decrypt the associated video stream; a delay line that delays the compressed video stream; a multiplexer that inserts the ECM into the delayed compressed video stream within a window just ahead of the detected RAP, said pairing of the ECM with the RAP allows the decoder to derive from the ECM the current encryption key needed to decrypt the associated video stream just in time to begin decoding the compressed video stream at the RAP; and an encryption box that encrypts the compressed video stream with a crypto codeword appropriate to the associated ECM. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A method, comprising:
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encoding a plurality of programs into respective compressed program streams, each compressed program stream including random access points (RAPs) at which a decoder may begin decoding for said program; multiplexing the compressed program streams to create a transport stream; continuously generating encryption keys; detecting the occurrence of RAPs in the transport stream; only upon detecting the occurrence of a RAP, triggering the generation of an entitlement control message (ECM) based on the current encryption key, said ECM including a message that allows the decoder to derive the current encryption key needed to decrypt the associated video stream; delaying the transport stream to insert the ECM into the transport stream within a time window just ahead of the detected RAP, said pairing of the ECM with the RAP allows the decoder to derive from the ECM the current encryption key needed to decrypt the associated program stream just in time to begin decoding the compressed program stream at the RAP; encrypting the stream with a crypto codeword appropriate to the associated ECM; and broadcasting the encrypted transport stream. - View Dependent Claims (27)
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Specification