Selective encryption to enable multiple decryption keys
AssigneesSony Corporation, Sony Electronics Inc.
InventorBrant L. Candelore
Life of this patent
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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.
Claims54
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;
- and
- 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.
A method of decrypting and decoding selectively encrypted digital video content, comprising:
- receiving packets of digital video, certain of the packets being unencrypted and certain of the packets being encrypted, wherein certain of the encrypted packets carry data encrypted under a first encryption key and certain other packets carry information encrypted under a second encryption key;
- 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.
A selective encryption decoder, for decrypting and decoding selectively encrypted digital video content, comprising:
- a demultiplexer that receives packets of digital video, certain of the packets being unencrypted and certain of the packets being encrypted under a first encryption key and certain of the packets being encrypted under a second encryption key;
- 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.
A selective encryption encoder, comprising:
- 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;
- and
- a first encrypter for encrypting the selected packets using a first and second encryption key.
A television set-top box, comprising:
- a receiver receiving a digital television signal comprising:
- a plurality of unencrypted packets;
- and
- a plurality of encrypted packets, the encrypted packets being encrypted under first and second encryption keys;
- 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.
A computer readable medium that carries instructions that when executed on a programmed processor to facilitate operation of a video receiver device to decrypt and decode a selectively encoded digital video signal wherein the instructions comprise:
- a code segment that controls a demultiplexer that receives packets of digital video, certain of the packets being unencrypted and certain of the packets being encrypted under a first encryption key and certain of the packets being encrypted under a second encryption key;
- 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.
A selectively encrypted digital video signal embodied in a carrier wave, comprising:
- a stream of packets of video data, wherein the stream of packets when not encrypted represent a segment of video content;
- certain of the packets being unencrypted and certain of the packets being encrypted, wherein certain of the encrypted packets are encrypted using a first encryption key and certain of the packets are encrypted using a second encryption key;
- a first segment of code that identifies the unencrypted packets by a first packet identifier (PID);
- a second segment of code that identifies the packets encrypted under the first encryption key by the first packet identifier (PID).
- a third segment of code that identifies the packets encrypted under the second encryption key by a second packet identifier (PID).
Dependencies are inferred from the claim text.