Content scrambling with minimal impact on legacy devices

• US 7,292,692 B2
• Filed: 01/29/2004
• Issued: 11/06/2007
• Est. Priority Date: 03/25/2003
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Inventors: Bonan, James, Candelore, Brant L., Eyer, Mark Kenneth
• Primary Examiner(s): Barron, Jr., Gilberto
• Assistant Examiner(s): LEMMA, SAMSON B
• Application Number:
  US10/767,421
• Publication Number:
  US 20040240668A1
• Time in Patent Office: 1,377 Days
• Field of Search: 380/212, 380/201
• US Class Current: 380/212
• CPC Class Codes: H04N 21/23476 by partially encrypting, e.g. encrypting the ending portion of a movie
• CPC Class Codes: H04N 21/235 Processing of additional data, e.g. scrambling of additional data or processing content descriptors
• CPC Class Codes: H04N 21/434 Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream demultiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/435 Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream
• CPC Class Codes: H04N 7/162 Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

An encryption arrangement for television programs or other digital programming consistent with certain embodiments sends content completely in-the-clear and also encrypts only a portion of the content required for full presentation of a television program. The arrangement allows interoperability between new TVs that can handle encryption and older TVs that cannot. Regulations prevent new TVs from receiving only the clear content. New TVs are made to descramble the encrypted portions of the content. Older legacy TVs can receive all the content in the clear. The encrypted portions are chosen so that dramatically less bandwidth is required as compared to full dual carriage of the content. Licensing provisions relating to the encryption technology can be used to control unauthorized use of content. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

Claims

1. A method of encrypting a digital television signal, comprising:

examining unencrypted packets of data in the digital television signal to identify a selected packet type;

duplicating packets identified as being of a selected packet type to produce pairs of duplicated packets;

encrypting one of each pair of the duplicated packets;

inserting the encrypted packets along with the unencrypted packets of the selected packet type into the digital television signal along with the unencrypted packets of data that are not of the selected packet type to produce a selectively encrypted digital television signal that contains duplicate packets of the selected packet type with one of the duplicate packets being encrypted while the other of the duplicated packets remains unencrypted; and

broadcasting the selectively encrypted television signal over a terrestrial broadcast transmission system.

2. The method according to claim 1, further comprising distributing an ATSC broadcast flag with the selectively encrypted digital television signal.

3. The method according to claim 1, wherein the selectively encrypted television signal represents one or more channels in a transport stream.

4. The method according to claim 1, wherein a key is used to encrypt the duplicate packets, and wherein the key is a function of copy control information associated with the digital television signal.

5. The method according to claim 1, wherein a key is used to encrypt the duplicate packets, and wherein the key is a function of global ATSC defined keys.

6. The method according to claim 1, wherein the selected packet type comprises packets carrying information that is needed to decompress the digital television signal.

7. The method according to claim 1, further comprising assigning a packet identifier to the unencrypted packets.

8. The method according to claim 1, further comprising assigning the packet identifier to the encrypted packets.

9. The method according to claim 1, wherein the packet identifier is a primary packet identifier;

and a secondary packet identifier is assigned to the encrypted packets.

23. The method according to claim 1, wherein the unencrypted packets carry a first continuity counter and wherein the encrypted packets carry a second continuity counter.

24. The method according to claim 1, wherein the first packets carry a first continuity counter and wherein the second packets carry a second continuity counter.

10. A method of encrypting a digital television signal, comprising:

examining unencrypted packets of data in the digital television signal to identify a selected packet type;

identifying packets as being of the selected packet type to produce first packets;

duplicating and encrypting duplicates of the packets identified as being of the selected packet type using an encryption method to produce second packets while retaining the first packets in an unencrypted state;

replacing the unencrypted packets of the selected packet type with the first packets and the second packets in the digital television signal to produce a selectively dual encrypted television signal that contains duplicate packets of the selected packet type with one of the duplicate packets being encrypted while the other of the duplicated packets remains unencrypted; and

broadcasting the selectively encrypted television signal over a terrestrial broadcast transmission system.

11. The method according to claim 10, further comprising assigning a packet identifier to the unencrypted packets.

12. The method according to claim 10, further comprising assigning the packet identifier to the encrypted packet.

13. The method according to claim 10, wherein the digital television signal is compressed, and wherein the encrypted packets comprises a packet type that is needed to decompress the digital television signal if the duplicated packets sent in the clear are ignored.

14. A television receiver, comprising:

a receiver receiving a terrestrial broadcast digital television signal, wherein the television signal has a plurality of unencrypted packets and a plurality of encrypted packets, wherein the encrypted packets duplicate some of the unencrypted packets and contain information required to decode the digital television signal;

a decrypter that decrypts the encrypted packets and drops the transmitted unencrypted version of the same packets; and

a decoder that decodes the unencrypted packets and the decrypted packets to produce a signal suitable for play on a television set.

15. The television receiver according to claim 14, wherein the digital television signal complies with an MPEG standard, and wherein the unencrypted packets are identified by a primary packet identifier, and the encrypted packets are identified by a secondary packet identifier.

16. The television receiver according to claim 14, wherein the digital television signal is compressed, and wherein the encrypted packets comprises a packet type that is needed to decompress the digital television signal if the duplicated packets sent in the clear are ignored.

25. A television receiver according to claim 14, wherein the unencrypted packets carry a first continuity counter and wherein the encrypted packers carry a second continuity counter.

17. A method of decoding a selectively encrypted terrestrial broadcast television program, comprising:

receiving a selectively encrypted terrestrial broadcast digital television program comprising a plurality of packets, wherein certain packets of the plurality of packets are encrypted and a remainder of the packets are unencrypted, wherein the encrypted packets are also sent unencrypted and contain information that is required for correct decoding of the television program; and

decrypting the encrypted packets to produce decrypted packets; and

decoding the decrypted packets and the unencrypted packets to produce a decoded television signal.

18. The method according to claim 17, wherein the selectively encrypted television program is a digital television program, and wherein the certain encrypted packets comprise packets that are needed to decode the television program if the duplicated packets sent in the clear are ignored.

19. The method according to claim 17, wherein the terrestrial broadcast selectively encrypted television program complies with a digital satellite service or digital cable transport standard, and wherein the encrypted packets carry a payload of a packetized elementary stream header.

26. The method according to claim 17, wherein the unencrypted packets carry a first continuity counter and wherein the encrypted packets carry a second continuity counter.

20. A method of decoding selectively encrypted content, comprising:

receiving selectively encrypted digital content wherein the selectively encrypted digital content contains duplicate packets of the selected packet type with one of the duplicate packets being encrypted while the other of the duplicated packets remains unencrypted the encrypted content comprising information needed for correct decoding of the selectively encrypted content if the duplicated unencrypted content is ignored; and

decrypting the encrypted content under the encryption system to produce decrypted content.

21. The method according to claim 20, further comprising decoding the unencrypted content, ignoring the duplicated unencrypted content, and the decoding decrypted content to decode the selectively encrypted content.

22. The method according to claim 20, wherein the digital television content is broadcast using a signal that complies with a digital satellite service or digital cable transport standard, and wherein the encrypted packets carry a payload of a packetized elementary stream header.

27. The method according to claim 20, wherein the unencrypted packets carry a first continuity counter and wherein the encrypted packets carry a second continuity counter.