Slice mask and moat pattern partial encryption

• US 20030152226A1
• Filed: 10/18/2002
• Published: 08/14/2003
• Est. Priority Date: 01/02/2002
• 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: Candelore, Brant L., Pedlow, Leo M. Jr., Derovanessian, Henry
• Granted Patent: US 7,155,012 B2
• Time in Patent Office: Days
• US Class Current: 380/218
• CPC Class Codes: H04K 1/00 Secret communication
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 9/14 using a plurality of keys or algorithms
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 21/234345 the reformatting operation being performed only on part of the stream, e.g. a region of the image or a time segment
• CPC Class Codes: H04N 21/23439 for generating different versions
• 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 21/236 Assembling of a multiplex stream, e.g. transport stream, by combining a video stream with other content or additional data, e.g. inserting a URL [Uniform Resource Locator] into a video stream, multiplexing software data into a video stream; Remultiplexing of multiplex streams; Insertion of stuffing bits into the multiplex stream, e.g. to obtain a constant bit-rate; Assembling of a packetised elementary stream multiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/23608 Remultiplexing multiplex streams, e.g. involving modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/2362 Generation or processing of Service Information [SI]
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/238 Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams hybrid fiber coaxial [HFC] networks for downstream channel allocation for video distribution H04L12/2801; flow control in packet networks H04L47/10; real-time communication protocols in data switching networks H04L65/00; scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/23897 by partially encrypting, e.g. encrypting only the ending portion of a movie
• CPC Class Codes: H04N 21/25435 involving characteristics of content or additional data, e.g. video resolution or the amount of advertising
• CPC Class Codes: H04N 21/25833 involving client hardware characteristics, e.g. manufacturer, processing or storage capabilities allocation of resources considering hardware capabilities in multiprogramming arrangements G06F9/5044; allocation of resources considering software capabilities in multiprogramming arrangements G06F9/5055
• CPC Class Codes: H04N 21/25875 involving end-user authentication restricting access to computer systems by authenticating users using a predetermined code G06F21/33; arrangements for secret or secure communication including means for verifying the identity or authority of a user of the system H04L9/32; networks authentication protocols H04L63/08; authentication in wireless network security H04W12/06
• CPC Class Codes: H04N 21/26606 for generating or managing entitlement messages, e.g. Entitlement Control Message [ECM] or Entitlement Management Message [EMM] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/2668 Creating a channel for a dedicated end-user group, e.g. insertion of targeted commercials based on end-user profiles information retrieval from the Internet by querying with filtering and personalisation G06F16/9535; arrangements for replacing or switching information during the broadcast H04H20/10; push services over packet-switching network H04L12/1859; adaptation of message content in packet-switching networks H04L51/063
• CPC Class Codes: H04N 21/4331 Caching operations, e.g. of an advertisement for later insertion during playback
• CPC Class Codes: H04N 21/4333 : Processing operations in response to a pause request
• 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 21/4344 : Remultiplexing of multiplex streams, e.g. by modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/4345 : Extraction or processing of SI, e.g. extracting service information from an MPEG stream
• CPC Class Codes: H04N 21/4347 : Demultiplexing of several video streams
• 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 21/43607 : Interfacing a plurality of external cards, e.g. through a DVB Common Interface [DVB-CI]
• CPC Class Codes: H04N 21/43856 : by partial decryption, e.g. decrypting a multiplex stream that has been partially encrypted
• CPC Class Codes: H04N 21/440245 : the reformatting operation being performed only on part of the stream, e.g. a region of the image or a time segment
• CPC Class Codes: H04N 21/440281 : by altering the temporal resolution, e.g. by frame skipping television signal recording using magnetic recording on tape for reproducing at a rate different from the recording rate H04N5/783
• CPC Class Codes: H04N 21/44055 : by partially decrypting, e.g. decrypting a video stream that has been partially encrypted
• CPC Class Codes: H04N 21/4516 : involving client characteristics, e.g. Set-Top-Box type, software version or amount of memory available
• CPC Class Codes: H04N 21/454 : Content or additional data filtering, e.g. blocking advertisements
• CPC Class Codes: H04N 21/458 : Scheduling content for creating a personalised stream, e.g. by combining a locally stored advertisement with an incoming stream; Updating operations, e.g. for OS modules ; time-related management operations arrangements for replacing or switching information during the broadcast or during the distribution H04H20/10
• CPC Class Codes: H04N 21/4623 : Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/47202 : for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 21/63345 : by transmitting keys key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 21/812 : involving advertisement data advertising per se G06Q30/02
• CPC Class Codes: H04N 21/835 : Generation of protective data, e.g. certificates protecting software against unauthorised usage in a vending or licensing environment G06F21/10
• CPC Class Codes: H04N 5/783 : Adaptations for reproducing at a rate different from the recording rate
• CPC Class Codes: H04N 5/913 : for scrambling ; for copy protection
• 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 7/163 : by receiver means only
• CPC Class Codes: H04N 7/165 : Centralised control of user terminal subsequent to an upstream request signal H04N7/17345; Registering at central by two-way working H04N7/17309
• 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
• CPC Class Codes: H04N 7/52 : Systems for transmission of a pulse code modulated video signal with one or more other pulse code modulated signals, e.g. an audio signal or a synchronizing signal assembling of a multiplex stream by combining a video stream with other content or additional data, remultiplexing of multiplex streams, insertion of stuffing bits into the multiplex stream, assembling of a packetised elementary stream at server side H04N21/236; disassembling of a multiplex stream, remultiplexing of multiplex streams, extraction or processing of Service Information, disassembling of packetised elementary stream at client side H04N21/434
• CPC Class Codes: H04N 9/7925 : for more than one standard

Abstract

A selective encryption encoder consistent with certain embodiments of the invention has vertical and/or horizontal stripes encrypted. In one embodiment, packets are examined in the digital video signal to identify a specified packet type, the specified packet type being both packets carrying intra-coded data representing a pattern of horizontal stripes across an image and packets carrying intra-coded data representing a pattern of vertical stripes across an image. The packets identified as being of the specified packet type are encrypted using a first encryption method to produce first encrypted packets. These first encrypted packets are then used to replace the unencrypted packets in the digital video signal to produce a partially encrypted video signal. The packets of the specified type can also be multiple encrypted and replaced in the data stream to produce a multiple encrypted video data stream.

Claims

1. A method of partially dual encrypting a digital video signal, comprising:

examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a pattern of horizontal stripes across an image;

encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets;

encrypting the packets identified as being of the specified packet type using a second encryption method 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.

2. The method according to claim 1, wherein the horizontal stripes are encrypted by encryption of slice headers in the horizontal stripes.

3. The method according to claim 2, wherein the horizontal stripes are encrypted by encryption of slice headers plus the first macroblock in each slice of the horizontal stripes.

4. The method according to claim 1, wherein the horizontal stripes are encrypted by encryption of macroblocks containing intra-coded data in the horizontal stripes.

5. The method according to claim 1, wherein the horizontal stripes are encrypted by encryption of all macroblocks in the horizontal stripes.

6. The method according to claim 1, wherein the horizontal stripes are encrypted by encryption of a predefined pattern of macroblocks in the horizontal stripes.

7. The method according to claim 1, wherein the horizontal stripes are encrypted by encryption of a predefined pattern of packets in the horizontal stripes.

8. The method according to claim 1, wherein the horizontal stripes are encrypted according to a binary array forming a slice mask, and wherein the binary array provides a code for encryption of slices within the image.

9. The method according to claim 8, wherein the horizontal stripes are encrypted by encryption of slice headers for slices coded for encryption.

10. The method according to claim 8, wherein the slices are encrypted by encryption of slice headers plus a first macroblock for slices coded for encryption.

11. The method according to claim 8, wherein the slices are encrypted by encryption of macroblocks containing intra-coded data for slices coded for encryption.

12. The method according to claim 8, wherein the horizontal stripes are encrypted by encryption of all macroblocks in the horizontal stripes.

13. The method according to claim 8, wherein the horizontal stripes are encrypted by encryption of a predefined pattern of macroblocks in the horizontal stripes.

14. The method according to claim 8, wherein the horizontal stripes are encrypted by encryption of a predefined pattern of packets in the horizontal stripes.

15. The method according to claim 1, wherein the pattern of horizontal stripes corresponds to odd numbered slices and even numbered slices on alternating video frames.

16. A computer readable medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a digital video signal according to claim 1.

17. The computer readable medium of claim 16, wherein the medium comprises one of an electronic storage medium and a carrier wave.

18. An electronic transmission medium carrying an encrypted digital video signal encrypted by the method according to claim 1.

19. A selective encryption encoder, comprising:

a packet identifier that identifies packets of a specified packet type, the specified packet type comprising packets carrying data representing a pattern of horizontal stripes across an image;

a packet duplicator that duplicates the identified packets to produce first and second sets of the identified packets;

means for sending and receiving packets to and from a primary encryption encoder to encrypt the first set of identified packets under a first encryption method;

a secondary encrypter for encrypting the second set of identified packets under a second encryption method.

20. The selective encryption encoder according to claim 19, wherein the horizontal stripes are encrypted by encryption of slice headers in the horizontal stripes.

21. The selective encryption encoder according to claim 20, wherein the horizontal stripes are encrypted by encryption of slice headers plus the first macroblock in each slice of the horizontal stripes.

22. The selective encryption encoder according to claim 19, wherein the horizontal stripes are encrypted by encryption of macroblocks containing intra-coded data in the horizontal stripes.

23. The selective encryption encoder according to claim 19, wherein the horizontal stripes are encrypted by encryption of all macroblocks in the horizontal stripes.

24. The selective encryption encoder according to claim 19, wherein the horizontal stripes are encrypted by encryption of a predefined pattern of macroblocks in the horizontal stripes.

25. The selective encryption encoder according to claim 19, wherein the horizontal stripes are encrypted by encryption of a predefined pattern of packets in the horizontal stripes.

26. The selective encryption encoder according to claim 19, wherein the horizontal stripes are encrypted according to a binary array forming a slice mask, and wherein the binary array provides a code for encryption of slices within the image.

27. The selective encryption encoder according to claim 26, wherein the binary array is 2-dimensional with one dimension representing the slice number, and other dimension representing either one of packets and macroblocks in each slice.

28. The selective encryption encoder according to claim 26, wherein the horizontal stripes are encrypted by encryption of slice headers for slices coded for encryption.

29. The selective encryption encoder according to claim 26, wherein the slices are encrypted by encryption of slice headers plus a first macroblock for slices coded for encryption.

30. The selective encryption encoder according to claim 26, wherein the slices are encrypted by encryption of macroblocks containing intra-coded data for slices coded for encryption.

31. The selective encryption encoder according to claim 19, wherein the pattern of horizontal stripes corresponds to odd numbered slices and even numbered slices on alternating video frames.

32. The selective encryption encoder according to claim 19, wherein the horizontal stripes are encrypted according to a two-dimensional binary array with one dimension representing the slice number, and other dimension representing either one of packets and macroblocks in each slice, and wherein the binary array provides a code for encryption of the packets or macroblocks comprising the slices within the image.

33. A method of partially encrypting a digital video signal, comprising:

examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a pattern of horizontal stripes across an image;

encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets; and

replacing the unencrypted packets of the specified packet type with the first encrypted packets in the digital video signal to produce a partially encrypted video signal.

34. The method according to claim 33, further comprising encrypting the packets identified as being of the specified packet type using a second encryption method to produce second encrypted packets;

and

inserting the second encrypted packets into the digital video signal to produce a dual partially encrypted video signal.

35. The method according to claim 33, wherein the horizontal stripes are encrypted by encryption of slice headers in the horizontal stripes.

36. The method according to claim 35, wherein the horizontal stripes are encrypted by encryption of slice headers plus the first macroblock in the horizontal stripes.

37. The method according to claim 33, wherein the horizontal stripes are encrypted by encryption of macroblocks containing intra-coded data in the horizontal stripes.

38. The method according to claim 33, wherein the horizontal stripes are encrypted according to a binary array forming a slice mask, and wherein the binary array provides a code for encryption of slices within the image.

39. The method according to claim 38, wherein the horizontal stripes are encrypted by encryption of slice headers for slices coded for encryption.

40. The method according to claim 38, wherein the slices are encrypted by encryption of slice headers plus a first macroblock for slices coded for encryption.

41. The method according to claim 38, wherein the slices are encrypted by encryption of macroblocks containing intra-coded data for slices coded for encryption.

42. The method according to claim 33, wherein the horizontal stripes are encrypted by encryption of all macroblocks in the horizontal stripes.

43. The method according to claim 33, wherein the horizontal stripes are encrypted by encryption of a predefined pattern of macroblocks in the horizontal stripes.

44. The method according to claim 33, wherein the horizontal stripes are encrypted by encryption of a predefined pattern of packets in the horizontal stripes.

45. The method according to claim 33, wherein the pattern of horizontal stripes corresponds to odd numbered slices and even numbered slices on alternating video frames.

46. The method according to claim 33, wherein the pattern of horizontal stripes changes from frame-to-frame.

47. The method according to claim 33, wherein the pattern of horizontal stripes changes periodically.

48. The method according to claim 33, wherein the pattern of horizontal stripes is more dense in an active region of the image.

49. The method according to claim 33, wherein the horizontal stripes are encrypted according to a two-dimensional binary array with one dimension representing the slice number, and other dimension representing either one of packets and macroblocks in each slice, and wherein the binary array provides a code for encryption of the packets or macroblocks comprising the slices within the image.

50. A computer readable medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a digital video signal according to claim 33.

51. The computer readable medium of claim 50, wherein the medium comprises one of an electronic storage medium and a carrier wave.

52. An electronic transmission medium carrying an encrypted digital video signal encrypted by the method according to claim 33.

53. A method of partially encrypting a digital video signal, comprising:

examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets containing slice headers for slices representing a pattern of horizontal stripes across an image;

encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets; and

replacing the unencrypted packets of the specified packet type with the first encrypted packets in the digital video signal to produce a partially encrypted video signal.

54. A computer readable medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a digital video signal according to claim 53.

55. The computer readable medium of claim 54, wherein the medium comprises one of an electronic storage medium and a carrier wave.

56. An electronic transmission medium carrying an encrypted digital video signal encrypted by the method according to claim 53.

57. A method of partially dual encrypting a digital video signal, comprising:

examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a pattern of vertical stripes across an image;

encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets;

encrypting the packets identified as being of the specified packet type using a second encryption method 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.

58. The method according to claim 57, wherein the vertical stripes are encrypted by encryption of macroblocks containing intra-coded data in the vertical stripes.

59. The method according to claim 57, wherein the vertical stripes are encrypted according to a binary array forming a moat mask, and wherein the binary array provides a code for encryption of vertical stripes within the image.

60. The method according to claim 59, wherein the vertical stripes are encrypted by encryption of macroblocks containing intra-coded data within the vertical stripes coded for encryption.

61. A computer readable medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a digital video signal according to claim 57.

62. The computer readable medium of claim 61, wherein the medium comprises one of an electronic storage medium and a carrier wave.

63. An electronic transmission medium carrying an encrypted digital video signal encrypted by the method according to claim 57.

64. A selective encryption encoder, comprising:

a packet identifier that identifies packets of a specified packet type, the specified packet type comprising packets carrying data representing a pattern of vertical stripes across an image;

a packet duplicator that duplicates the identified packets to produce first and second sets of the identified packets;

means for sending and receiving packets to and from a primary encryption encoder to encrypt the first set of identified packets under a first encryption method;

a secondary encrypter for encrypting the second set of identified packets under a second encryption method.

65. The selective encryption encoder according to claim 64, wherein the vertical stripes are encrypted by encryption of macroblocks containing intra-coded data in the vertical stripes.

66. The selective encryption encoder according to claim 64, wherein the vertical stripes are encrypted according to a binary array forming a vertical moat mask, and wherein the binary array provides a code for encryption of vertical stripes within the image.

67. The selective encryption encoder according to claim 64, wherein the vertical stripes are encrypted by encryption of macroblocks containing intra-coded data for slices coded for encryption.

68. A method of partially encrypting a digital video signal, comprising:

examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a pattern of vertical stripes across an image;

encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets; and

replacing the unencrypted packets of the specified packet type with the first encrypted packets in the digital video signal to produce a partially encrypted video signal.

69. The method according to claim 68, further comprising encrypting the packets identified as being of the specified packet type using a second encryption method to produce second encrypted packets;

and

inserting the second encrypted packets into the digital video signal to produce a dual partially encrypted video signal.

70. The method according to claim 68, wherein the vertical stripes are encrypted by encryption of macroblocks containing intra-coded data in the vertical stripes.

71. The method according to claim 68, wherein the vertical stripes are encrypted according to a binary array forming a vertical moat mask, and wherein the binary array provides a code for encryption of stripes within the image.

72. The method according to claim 71, wherein the stripes are encrypted by encryption of macroblocks containing intra-coded data for stipes coded for encryption.

73. A computer readable medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a digital video signal according to claim 68.

74. The computer readable medium of claim 73, wherein the medium comprises one of an electronic storage medium and a carrier wave.

75. An electronic transmission medium carrying an encrypted digital video signal encrypted by the method according to claim 68.

76. A method of partially encrypting a digital video signal, comprising:

examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying intra-coded data within a pattern of vertical stripes across an image;

encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets; and

replacing the unencrypted packets of the specified packet type with the first encrypted packets in the digital video signal to produce a partially encrypted video signal.

77. A computer readable medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a digital video signal according to claim 76.

78. The computer readable medium of claim 77, wherein the medium comprises one of an electronic storage medium and a carrier wave.

79. An electronic transmission medium carrying an encrypted digital video signal encrypted by the method according to claim 76.

80. A method of partially dual encrypting a digital video signal, comprising:

examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising both packets carrying data representing a pattern of horizontal stripes across an image and packets carrying data representing a pattern of vertical stripes across the image;

encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets;

encrypting the packets identified as being of the specified packet type using a second encryption method 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.

81. The method according to claim 80, wherein the horizontal stripes are encrypted by encryption of slice headers in the horizontal stripes.

82. The method according to claim 81, wherein the horizontal stripes are encrypted by encryption of slice headers plus the first macroblock in the horizontal stripes.

83. The method according to claim 80, wherein the horizontal stripes are encrypted by encryption of macroblocks containing intra-coded data in the horizontal stripes.

84. The method according to claim 80, wherein the horizontal stripes are encrypted according to a binary array forming a slice mask, and wherein the binary array provides a code for encryption of slices within the image.

85. The method according to claim 80, wherein the vertical stripes are encrypted by encryption of macroblocks containing intra-coded data in the vertical stripes.

86. The method according to claim 80, wherein the vertical stripes are encrypted according to a binary array forming a moat mask, and wherein the binary array provides a code for encryption of vertical stripes within the image.

87. The method according to claim 80, wherein the vertical stripes are encrypted by encryption of macroblocks containing intra-coded data within the vertical stripes coded for encryption.

88. The method according to claim 80, wherein the horizontal stripes are encrypted according to a two-dimensional binary array with one dimension representing the slice number, and other dimension representing either one of packets and macroblocks in each slice, and wherein the binary array provides a code for encryption of the packets or macroblocks comprising the slices within the image.

89. A computer readable medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a digital video signal according to claim 80.

90. The computer readable medium of claim 80, wherein the medium comprises one of an electronic storage medium and a carrier wave.

91. An electronic transmission medium carrying an encrypted digital video signal encrypted by the method according to claim 80.

92. A selective encryption encoder, comprising:

a packet identifier that identifies packets of a specified packet type, the specified packet type comprising both packets carrying data representing a pattern of horizontal stripes across an image and packets carrying data representing a pattern of vertical stripes across an image;

a packet duplicator that duplicates the identified packets to produce first and second sets of the identified packets;

means for sending and receiving packets to and from a primary encryption encoder to encrypt the first set of identified packets under a first encryption method;

a secondary encrypter for encrypting the second set of identified packets under a second encryption method.

93. The selective encryption encoder according to claim 92, wherein the horizontal stripes are encrypted by encryption of slice headers in the horizontal stripes.

94. The selective encryption encoder according to claim 93, wherein the horizontal stripes are encrypted by encryption of slice headers plus the first macroblock in the horizontal stripes.

95. The selective encryption encoder according to claim 92, wherein the horizontal stripes are encrypted by encryption of macroblocks containing intra-coded data in the horizontal stripes.

96. The selective encryption encoder according to claim 92, wherein the horizontal stripes are encrypted according to a binary array forming a slice mask, and wherein the binary array provides a code for encryption of slices within the image.

97. The selective encryption encoder according to claim 92, wherein the vertical stripes are encrypted by encryption of macroblocks containing intra-coded data in the vertical stripes.

98. The selective encryption encoder according to claim 92, wherein the vertical stripes are encrypted according to a binary array forming a moat mask, and wherein the binary array provides a code for encryption of vertical stripes within the image.

99. The selective encryption encoder according to claim 92, wherein the vertical stripes are encrypted by encryption of macroblocks containing intra-coded data within the vertical stripes coded for encryption.

100. The selective encryption encoder according to claim 92, wherein the horizontal stripes are encrypted according to a two-dimensional binary array with one dimension representing the slice number, and other dimension representing either one of packets and macroblocks in each slice, and wherein the binary array provides a code for encryption of the packets or macroblocks comprising the slices within the image.

101. A method of partially encrypting a digital video signal, comprising:

examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising both packets carrying data representing a pattern of horizontal stripes across an image and packets carrying data representing a pattern of vertical stripes across an image;

encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets; and

replacing the unencrypted packets of the specified packet type with the first encrypted packets in the digital video signal to produce a partially encrypted video signal.

102. The method according to claim 101, wherein the horizontal stripes are encrypted by encryption of slice headers in the horizontal stripes.

103. The method according to claim 102, wherein the horizontal stripes are encrypted by encryption of slice headers plus the first macroblock in the horizontal stripes.

104. The method according to claim 101, wherein the horizontal stripes are encrypted by encryption of macroblocks containing intra-coded data in the horizontal stripes.

105. The method according to claim 101, wherein the horizontal stripes are encrypted according to a binary array forming a slice mask, and wherein the binary array provides a code for encryption of slices within the image.

106. The method according to claim 101, wherein the vertical stripes are encrypted by encryption of macroblocks containing intra-coded data in the vertical stripes.

107. The method according to claim 101, wherein the vertical stripes are encrypted according to a binary array forming a moat mask, and wherein the binary array provides a code for encryption of vertical stripes within the image.

108. The method according to claim 101, wherein the vertical stripes are encrypted by encryption of macroblocks containing intra-coded data within the vertical stripes coded for encryption.

109. The method according to claim 101, wherein the horizontal stripes are encrypted by encryption of all macroblocks in the horizontal stripes.

110. The method according to claim 101, wherein the horizontal stripes are encrypted by encryption of a predefined pattern of macroblocks in the horizontal stripes.

111. The method according to claim 101, wherein the horizontal stripes are encrypted by encryption of a predefined pattern of packets in the horizontal stripes.

112. The method according to claim 101, wherein the horizontal stripes are encrypted according to a two-dimensional binary array with one dimension representing the slice number, and other dimension representing either one of packets and macroblocks in each slice, and wherein the binary array provides a code for encryption of the packets or macroblocks comprising the slices within the image.

113. A computer readable medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a digital video signal according to claim 101.

114. The computer readable medium of claim 113, wherein the medium comprises one of an electronic storage medium and a carrier wave.

115. An electronic transmission medium carrying an encrypted digital video signal encrypted by the method according to claim 101.

116. A method of partially encrypting a digital video signal, comprising:

examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type representing a pattern of horizontal stripes across an image and packets representing a pattern of vertical stripes across the image;

encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets; and

replacing the unencrypted packets of the specified packet type with the first encrypted packets in the digital video signal to produce a partially encrypted video signal.

117. A computer readable medium storing instructions which, when executed on a programmed processor, carry out the method of encrypting a digital video signal according to claim 116.

118. The computer readable medium of claim 117, wherein the medium comprises one of an electronic storage medium and a carrier wave.

119. An electronic transmission medium carrying an encrypted digital video signal encrypted by the method according to claim 116.

120. 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, wherein certain of the encrypted packets represent at least one of a pattern of horizontal stripes across an image and a pattern of vertical stripes across the image;

a decrypter that decrypts the encrypted packets; and

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

121. A selective encryption decoder, for decrypting and decoding a selectively encrypted digital video signal, comprising:

a demultiplexer that receives packets of digital video, certain of the packets being unencrypted and certain of the packets being encrypted, wherein certain of the encrypted packets represent at least one of a pattern of horizontal stripes across an image and a pattern of vertical stripes across the image;

the unencrypted packets having a first packet identifier (PID) and the encrypted packets having a second packet identifier (PID);

a decrypter receiving the encrypted packets having the second PID and decrypting the encrypted packets using a first encryption method to produce decrypted packets;

a PID remapper that changes at least one of the first and second PIDs so that the unencrypted packets and the decrypted packets have the same PID; and

a decoder that decodes the unencrypted and decrypted packets to produce a decoded video signal.

122. A method of decrypting and decoding a selectively encrypted digital video signal, 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 represent at least one of a pattern of horizontal stripes across an image and a pattern of vertical stripes across the image;

the unencrypted packets having a first packet identifier (PID) and the encrypted packets having a second packet identifier (PID);

decrypting the encrypted packets having the second PID to produce decrypted packets;

remapping at least one of the first and second PIDs so that the unencrypted packets and the decrypted packets have the same PID; and

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

123. A computer readable medium storing instructions which, when executed on a programmed processor, carry out the method of decoding and decrypting a digital video signal according to claim 122.

124. The computer readable medium of claim 123, wherein the medium comprises one of an electronic storage medium and a carrier wave.

125. An electronic transmission medium carrying a digital video signal decoded and decrypted by the method according to claim 122.

126. A computer readable medium that carries instructions that when executes 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, wherein certain of the encrypted packets represent at least one of a pattern of horizontal stripes across an image and packets representing a pattern of vertical stripes across the image;

the unencrypted packets having a first packet identifier (PID) and the encrypted packets having a second packet identifier (PID);

a code segment that controls decryption of the encrypted packets to produce decrypted packets;

a code segment that controls remapping at least one of the first and second PIDs so that the unencrypted packets and the decrypted packets have the same PID; and

a code segment that controls decoding the unencrypted and decrypted packets to produce a decoded video signal.

127. The computer readable medium according to claim 126, wherein the medium comprises one of a carrier wave and a storage medium.

128. 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 represent at least one of a pattern of horizontal stripes across an image and a pattern of vertical stripes across the image;

a first segment of code that identifies the unencrypted packets by a first packet identifier (PID); and

a second segment of code that identifies the encrypted packets by a second packet identifier (PID).

129. A selectively encrypted digital video signal embodied in a computer readable medium, comprising:

a sequence of packets of video data, wherein the sequence of packets when not encrypted represent a segment of video content;

wherein certain of the packets are unencrypted;

wherein certain of the packets have been produced by decrypting encrypted packets;

wherein certain of the decrypted packets represent at least one of a pattern of horizontal stripes across an image and a pattern of vertical stripes across the image; and

a segment of code that identifies the unencrypted packets by a first packet identifier (PID); and

a segment of code that identifies the encrypted packets by a second packet identifier (PID).

130. The selectively encrypted digital video signal embodied in a computer readable medium according to claim 129, wherein the medium comprises one of a carrier wave and a storage medium.