Selective encryption to enable multiple decryption keys
First Claim
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1. A method of selectively encrypting digital video content, comprising;
- receiving a plurality of unencrypted packets containing the digital video content;
selecting certain of the packets of a specified type for encryption according to a selection criterion;
encrypting the selected packets using a first encryption key to produce first encrypted packets;
encrypting the selected packets using a second encryption key to produce second encrypted packets;
wherein the selected packets encrypted using the first encryption key and the selected packets encrypted using the second encryption key contain the same digital video content;
replacing the unencrypted packets of the specified packet type with the first encrypted packets and the second encrypted packets in the digital video signal to produce a partially dual encrypted video signal comprised of unencrypted packets along with first and second encrypted packets;
wherein the first encryption key is valid for a first segment of time and the second encryption key is valid for a subsequent time segment; and
transmitting the partially dual encrypted video signal to a receiver.
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Abstract
A selective encryption method and apparatus consistent with the invention duplicates selected packets in a file or data stream and multiple encrypts the packets using multiple encryption keys. Each encryption key is valid for a specific segment of time so that changes in entitlement keys used for decryption can be made without negatively impacting a customer'"'"'s ability to access content that has been paid for.
469 Citations
44 Claims
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1. A method of selectively encrypting digital video content, comprising;
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receiving a plurality of unencrypted packets containing the digital video content; selecting certain of the packets of a specified type for encryption according to a selection criterion; encrypting the selected packets using a first encryption key to produce first encrypted packets; encrypting the selected packets using a second encryption key to produce second encrypted packets; wherein the selected packets encrypted using the first encryption key and the selected packets encrypted using the second encryption key contain the same digital video content; replacing the unencrypted packets of the specified packet type with the first encrypted packets and the second encrypted packets in the digital video signal to produce a partially dual encrypted video signal comprised of unencrypted packets along with first and second encrypted packets; wherein the first encryption key is valid for a first segment of time and the second encryption key is valid for a subsequent time segment; and transmitting the partially dual encrypted video signal to a receiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of decrypting and decoding dual selectively encrypted digital video content, comprising:
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receiving partially dual encrypted video content comprising unencrypted packets along with first encrypted packets and second encrypted packets, wherein the first encrypted packets carry data encrypted under a first encryption, key and the second encrypted packets carry data encrypted under a second encryption key; wherein the first encrypted packets and the second encrypted packets contain the same digital video content; wherein the first encryption key is valid for a first period of time and the second encryption key is valid for a second period of time; determining which of the encrypted packets are encrypted under a currently valid encryption key; decrypting the encrypted packets having the currently valid encryption key; and decoding the unencrypted and decrypted packets to produce a decoded video signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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18. A selective encryption decoder, for decrypting and decoding selectively encrypted digital video content, comprising:
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a demultiplexer that receives dual selectively encrypted video content comprising unencrypted packets along with first encrypted packets and second encrypted packets, wherein the first encrypted packets carry data encrypted under a first encryption key and the second encrypted packets carry data encrypted under a second encryption key; wherein the first encrypted packets and tile second encrypted packets contain the same digital video content; wherein the first encryption key is valid for a first period of time and the second encryption key is valid for a second period of time; means for determining which of the first and second encryption keys are currently valid; a decrypter receiving the encrypted packets having the valid encryption key and decrypting the encrypted packets using a valid decryption key to produce decrypted packets; and a decoder that decodes the unencrypted and decrypted packets to produce a decoded video signal. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26)
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27. A selective encryption encoder, comprising:
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a packet identifier that identifies packets of a specified packet type; a packet duplicator that duplicates the identified packets to produce first and second sets of the identified packets in which the first and second identified packets contain the same digital video content; a first encrypter for encrypting the first set of identified packets using a first encryption key and for encrypting the second set of identified packets using a second encryption key, wherein the first encryption key is valid for a first time period and the second encryption key is valid for a second time period, to produce a dual selectively encrypted signal in which the first and second identified packets contain the same digital video content; and a transmitter that transmits the selectively encrypted signal to a recipient. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35)
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36. A television set-top box comprising:
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a receiver receiving a dual selectively encrypted digital television signal comprising; unencrypted packets along with first encrypted packets and second encrypted packets, wherein the first encrypted packets carry data encrypted under a first encryption key and the second encrypted packets carry data encrypted under a second encryption key; wherein the first encrypted packets and the second encrypted packets contain the same digital video content; wherein the first encryption key is valid for a first period of time and the second encryption key is valid for a second period of time; means for determining which of the first and second keys is valid; a decrypter that decrypts the encrypted packets using a valid decryption key; and a decoder that decodes the unencrypted packets and the decrypted packets to produce a signal suitable for play on a television set. - View Dependent Claims (37, 38, 39, 40)
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41. A tangible computer readable storage medium that carries instructions that when executed on a programmed processor facilitates operation of a video receiver device to decrypt and decode a selectively encoded digital video signal wherein the instructions comprise:
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a code segment that controls a demultiplexer that receives partially dual encrypted video content comprising unencrypted packets along with first encrypted packet and second encrypted packets, wherein the first encrypted packets carry data encrypted under first encryption key and the second encrypted packets carry data encrypted under a second encryption key; wherein the first encrypted packets and the second encrypted packets contain the same digital video content; wherein the first encryption key is valid for a first period of time and the second encryption key is valid for a second period of time; a code segment that determines which of the first and second keys are valid; a code segment that controls decryption of the encrypted packets under the valid key to produce decrypted packets; and a code segment that controls decoding the unencrypted and decrypted packets to produce a decoded video signal. - View Dependent Claims (42, 43, 44)
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Specification