Copy prevention method and apparatus for digital video system

• US RE41,074 E1
• Filed: 01/24/2005
• Issued: 01/12/2010
• Est. Priority Date: 11/26/1994
• Status: Expired due to Term

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Park, Tae Joon
• Primary Examiner(s): Lanier; Benjamin E
• Application Number:
  US11/040,606
• Time in Patent Office: 1,814 Days
• Field of Search: None
• US Class Current: 380/201
• CPC Class Codes: H04N 2005/91328 the copy protection signal being a copy management signal, e.g. a copy generation management signal [CGMS]
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 9/8042 involving data reduction
• CPC Class Codes: H04N 9/8063 using time division multiplex of the PCM audio and PCM video signals
• CPC Class Codes: H04N 9/8205 involving the multiplexing of an additional signal and the colour video signal

Abstract

A copy prevention method and apparatus for a digital video system is disclosed including the steps of: (a) adding a header area of a header start code and key field to a reproduced bit stream: (b) decrypting and transmitting the bit stream to which the header area is added: (c) detecting a key field of the decrypted and transmitted bit stream and detecting copy prevention information; and (d) encrypting the bit stream according to information detected from stop (c) and recording it an tape.A copy protection method including receiving encrypted digital data to be recorded, key information which is required to decrypt the encrypted digital data, and first copy control information which indicates a copy permission status of the encrypted digital data; and recording the encrypted digital data, the key information, and second copy control information on a digital recording medium, based on at least a status of the first copy control information.

Claims

1. A copy prevention method for a digital video system comprising the steps of:

(a) receiving a digital data stream reproduced from a digital medium;

(b) detecting an encryption key, which is a portion of said received digital data stream;

(c) decrypting said encryption key using key information;

(d) decrypting said received digital data stream based on said decrypted encryption key; and

(e) transmitting said decrypted digital data stream to at least one of a monitor and a digital recorder.

2. A copy prevention method for a digital video system as claimed in claim 1, wherein said key information is predetermined by said digital video system.

3. A copy prevention method for a digital video system as claimed in claim 1, wherein said decrypting step (d) is operated in units of predetermined block of said received digital data stream.

4. A copy prevention apparatus for a digital video system comprising:

receiving means for receiving a digital data stream reproduced from a digital medium;

a key detector to detect an encryption key, which is a portion of said received digital data stream;

a decryption unit to decrypt said encryption key using key information and to decrypt said received digital data stream based on said decrypted encryption key; and

a controller to control transmission of said decrypted digital data stream to at least one of a monitor and a digital recorder.

5. A copy prevention apparatus for a digital video system as claimed in claim 4, wherein said key information is predetermined by said digital video system.

6. A copy prevention apparatus for a digital video system as claimed in claim 4, wherein said decryption unit is operated in units of predetermined block of said received digital data stream.

7. A copy prevention method for a digital video system comprising the steps of:

(a) receiving a digital data stream reproduced from a digital medium;

(b) detecting an encryption key, which is a portion of said received digital data stream;

(c) decrypting said encryption key using key information;

(d) decrypting said received digital data stream based on said decrypted encryption key.

8. A copy prevention method for a digital video system as claimed in claim 7, wherein said key information is predetermined by said digital video system.

9. A copy prevention method for a digital video system as claimed in claim 7, wherein said decrypting step (d) is operated in units of predetermined block of said received digital data stream.

10. A copy prevention apparatus for a digital video system comprising:

receiving means for receiving a digital data stream reproduced from a digital medium;

a key detector to detect an encryption key, which is a portion of said received digital data stream;

a decryption unit to decrypt said encryption key using key information and to decrypt said received digital data stream based on said decrypted encryption key.

11. A copy prevention apparatus for a digital video system as claimed in claim 10, wherein said key information is predetermined by said digital video system.

12. A copy prevention apparatus for a digital video system as claimed in claim 10, wherein said decryption unit is operated in units of predetermined block of said received digital data stream.

13. A copy prevention method for a digital video system comprising the steps of:

(a) receiving a digital data stream reproduced from a digital medium;

(b) detecting an encryption key, which is a portion of said received digital data stream;

(c) decrypting said encryption key using predetermined key information;

(d) decrypting said received digital data stream based on said decrypted encryption key.

14. A copy prevention method for a digital video system as claimed in claim 13, wherein said decrypting step (d) is operated in units of predetermined block of said received digital data stream.

15. A copy prevention apparatus for a digital video system comprising:

receiving means for receiving a digital data stream reproduced from a digital medium;

a key detector to detect an encryption key, which is a portion of said received digital data stream;

a decryption unit to decrypt said encryption key using predetermined key information and to decrypt said received digital data stream based on said decrypted encryption key.

16. A copy prevention apparatus for a digital video system as claimed in claim 15, wherein said decrypting unit is operated in units of predetermined block of said received digital data stream.

17. A copy prevention method for a digital data system, comprising the steps of:

(a) receiving first key information;

(b) encrypting second key information using said first key information;

(c) encrypting digital data streams using said second key information; and

(d) recording at least said encrypted second key information and said encrypted digital data streams on a digital medium.

18. The method of claim 17, wherein said (b) randomly selects said second key information.

19. The method of claim 17, wherein said step (c) encrypts said digital data streams in blocks.

20. A copy prevention apparatus for a digital data system, comprising the steps of:

an encryption unit receiving first key information, encrypting second key information using said first key information, and encrypting digital data streams using said second key information; and

a controller controlling recording of at least said encrypted second key information and said encrypted digital data streams on a digital medium.

21. The apparatus of claim 20, wherein said encryption unit randomly selects said second key information.

22. The apparatus of claim 20, wherein said encryption unit encrypts said digital data streams in blocks.

23. A recording medium having a data structure for controlling operation of copy prevention function in a digital data processing device, comprising:

a digital data area storing digital data encrypted using first key information; and

a key information area storing said first key information encrypted using second key information, said first key information operatively controlling the decryption of said encrypted digital data in a digital data process device.

24. A copy prevention method for a digital data system, comprising:

receiving first key information, said first key information for encrypting digital data;

encrypting said first key information using second information; and

transferring said encrypted first key information.

25. The method of claim 24, wherein said encrypting step public key encrypts said second key information.

26. The method of claim 24, wherein said transferring step records said encrypted first key information on a digital medium.

27. The method of claim 24, wherein said transferring step transmits said encrypted first key information.

28. A copy prevention apparatus for a digital data system, comprising:

an encryption unit receiving first key information, said first key information for encrypting digital data, and encrypting said first key information using second key information; and

a controller controlling a transfer of said encrypted first key information.

29. The apparatus of claim 28, wherein said encryption unit public key encrypts said first key information.

30. The apparatus of claim 28, wherein said controller controls recording said encrypted first key information on a digital medium.

31. The apparatus of claim 28, wherein said controller controls transmitting said encrypted first key information.

32. A copy protection method, comprising:

receiving encrypted digital data to be recorded, key information which is required to decrypt the encrypted digital data, and first copy control information which indicates a copy permission status of the encrypted digital data; and

recording the encrypted digital data, the key information, and second copy control information on a digital recording medium, based on at least a status of the first copy control information,

wherein the encrypted digital data is partitioned into a GOP (Group Of Picture) unit, and

wherein the recording step includes recording the encrypted digital data partitioned into the GOP unit and recording the second copy control information followed by the GOP unit.

33. The method of claim 32, wherein said recording step records the encrypted digital data only when the first copy control information indicates that a copy is permitted.

34. The method of claim 33, wherein said recording step includes encrypting the key information and recording the encrypted key information in a control area followed by the encrypted digital data.

35. The method of claim 33, wherein the second copy control information indicates that the copy has been generated.

36. The method of claim 35, further comprising:

recording an identifier to identify that the second copy control information is included.

37. The method of claim 33, further comprising:

recording classification information to classify the encrypted digital data.

38. The method of claim 37, wherein the classification information is recorded in a header portion of the encrypted digital data.

39. The method of claim 32, wherein the key information is followed by the GOP unit.

40. A copy protection method, comprising:

receiving encrypted digital data to be recorded, key information which is required to decrypt the encrypted digital data, and first copy control information which indicates a copy permission status of the encrypted digital data; and

recording the encrypted digital data, the key information, and second copy control information on a digital recording medium, based on at least a status of the first copy control information,

wherein the received encrypted digital data is recorded as a GOP (Group Of Picture) unit, which is partitioned into a plurality of packets, each packet comprising a header portion and a data portion, and

wherein the second copy information is included in the header portion of at least one packet.

41. The method of claim 40, wherein an identifier is recorded in the header portion.

42. The method of claim 41, wherein the key information is recorded in a control data area followed by the GOP unit.

43. The method of claim 42, wherein classification information is recorded in the header portion of the packet, the classification information for classifying that the data portion of the packet is encrypted.

44. A copy protection method, comprising:

receiving encrypted digital data to be recorded, key information which is required to decrypt the encrypted digital data, and first copy control information which indicates a copy permission status of the encrypted digital data;

recording the encrypted digital data, the key information, and second copy control information on a digital recording medium, based on at least a status of the first copy control information, the encrypted digital content being partitioned into one or more first data units, the first data unit including a header portion and a data portion, and wherein said step of recording the encrypted digital data includes recording the one or more first data units; and

recording the second copy control information in the header portion followed by the data portion.

93. The method of claim 44, wherein said step of recording the encrypted digital data records the encrypted digital data only when the first copy control information indicates that a copy is permitted.

94. The method of claim 93, wherein said step of recording the encrypted digital data includes encrypting the key information and recording the encrypted key information in a control area followed by the encrypted digital data.

95. The method of claim 93, wherein the second copy control information indicates that the copy has been generated.

96. The method of claim 95, further comprising:

recording an identifier to identify that the second copy control information is included.

97. The method of claim 93, further comprising:

recording classification information to classify the encrypted digital data.

98. The method of claim 97, wherein the classification information is recorded in a header portion of the encrypted digital data.

45. A copy protection method, comprising:

providing digital content, key information for controlling at least a decryption of the digital content, and copy control information for controlling copying of the digital content, the digital content being partitioned into a GOP (Group Of Picture) unit; and

recording the key information, the copy control information and the digital content partitioned into the GOP unit on a digital recording medium,

wherein the copy control information is followed by the GOP unit.

46. The method of claim 45, wherein the key information in said providing step is encrypted key information.

47. The method of claim 46, wherein the encrypted key information is recorded in a control area followed by the digital content.

48. The method of claim 47, wherein the copy control information is recorded in the control area followed by the digital content.

49. The method of claim 46, wherein said recording step records the digital content as encrypted by the key information.

50. The method of claim 45, wherein said recording step includes recording a flag to indicate that the copy control information is included thereby identifying an existence of the copy control information.

51. The method of claim 50, wherein the flag and the copy control information are recorded in a control area followed by the digital content.

52. The method of claim 45, wherein said recording step further records a flag to indicate that the copy control information is included, in the area followed by the GOP unit.

53. A copy protection method, comprising:

providing digital content, key information for controlling at least decryption of the digital content, and copy control information for controlling copying of the digital content; and

recording the key information, the copy control information and the digital content on a digital recording medium, the digital content being partitioned into one or more first data units, the first data unit being partitioned into one or more second data units, the second data unit including a header portion and a data portion, and

the copy control information being included in the header portion followed by the data portion of at least one second data unit.

54. The method of claim 53, wherein said recording step further records a flag to indicate that the copy control information is included.

55. The method of claim 53, wherein the key information is recorded in a control data area followed by a first of the first data units.

56. A recording medium, comprising:

a plurality of first data units, which are partitioned into a plurality of second data units, which include a header portion and a data portion respectively, an encrypted digital content being included in the data portions of the second data units;

copy control information indicating whether or not a copy of the encrypted digital content is permitted;

an identifier which identifies whether or not the copy control information exists; and

encrypted key information, which is required to decrypt the encrypted digital content,

wherein the copy control information and the identifier are included in the header portion of the second data unit.

57. The recording medium of claim 56, wherein the copy control information and identifier are included in a control data area followed by a first of the first data units.

58. The recording medium of claim 56, wherein the copy control information can have a status to indicate that no more copies are permitted.

59. The recording medium of claim 57, wherein the encrypted key information is recorded in the control data area.

60. The recording medium of claim 59, wherein one of the plurality of first data units comprises at least one GOP (Group Of Picture) unit.

61. The recording medium of claim 56, wherein classification information is included in the header portion to indicate if the data portion is encrypted.

62. The recording medium of claim 56, wherein the encrypted digital content is decrypted only when the encrypted key information is normally decrypted.

63. A copy protection method, comprising:

retrieving encrypted digital content, first key information for decrypting the encrypted digital content, and copy control information which indicates whether or not a copy of the encrypted digital content is permitted; and

controlling a reproducing of the encrypted digital content from a recording medium based on the first key information and/or the copy control information, the digital content being partitioned into one or more first data units, the first data unit including a header portion and a data portion, the encrypted digital content being included in the data portion and the copy control information being included in the header portion followed by the data portion.

64. The method of claim 63, wherein said controlling step includes decrypting the encrypted digital content based on the first key information.

65. The method of claim 64, further comprising:

decrypting the first key information based on second key information, and then decrypting the encrypted digital content based on the decrypted first key information.

66. A copy protection apparatus, comprising:

a receiving unit configured to receive encrypted digital data to be recorded, key information which is required to decrypt the encrypted digital data, and first copy control information which indicates a copy permission status of the encrypted digital data;

a recording unit configured to record the encrypted digital data, the key information, and second copy control information on a digital recording medium; and

a controller operably coupled to the recording unit, to determine at least a status of the first copy control information, and to allow the recording unit to record the encrypted digital data based on the determined result,

wherein the encrypted digital data is partitioned into a GOP (Group Of Picture) unit, and

wherein the controller is further configured to control the recording unit to record the encrypted digital data in the GOP unit, and record the second copy control information in an area followed by the GOP unit.

67. The apparatus of claim 66, wherein said controller is configured to control the recording unit to record the encrypted digital data only when the first copy control information indicates that a copy is permitted as a result of the determination.

68. The apparatus of claim 67, further comprising:

an encrypting unit configured to encrypt the key information,

wherein the recording unit is further configured to record the encrypted key information in a control portion followed by the encrypted digital data, according to a control of the controller.

69. The apparatus of claim 67, wherein the second copy control information indicates that the copy has been generated.

70. The apparatus of claim 69, wherein the recording unit is further configured to record an identifier to identify that the second copy control information is included, according to a control of the controller.

71. The apparatus of claim 67, wherein the recording unit is further configured to record classification information to classify the encrypted digital data, according to a control of the controller.

72. The apparatus of claim 71, wherein the recording unit is further configured to record the classification information in a header portion of the encrypted digital data, under control of the controller.

73. The apparatus of claim 66, wherein the recording unit is further configured to record key information in the portion followed by the GOP unit, under control of the controller.

74. A copy protection apparatus, comprising:

a receiving unit configured to receive encrypted digital data to be recorded, key information which is required to decrypt the encrypted digital data, and first copy control information which indicates a copy permission status of the encrypted digital data;

a recording unit configured to record the encrypted digital data, the key information, and second copy control information on a digital recording medium; and

a controller operably coupled to the recording unit, to determine at least a status of the first copy control information, and to allow the recording unit to record the encrypted digital data based on the determined result, the received encrypted digital data being partitioned into a GOP (Group Of Picture) unit, which is partitioned into a plurality of packets, each packet comprising a header portion and a data portion,

wherein the recording unit is further configured to record the GOP unit, and record the second copy control information in the header portion of at least one packet under control of the controller.

75. The apparatus of claim 74, wherein the recording unit is further configured to record an identifier in the header portion, under control of the controller.

76. The apparatus of claim 75, wherein the recording unit is further configured to record the key information in a control data portion followed by the GOP unit, under control of the controller.

77. The apparatus of claim 76, wherein the recording unit is further configured to record classification information in the header portion of the packet under control of the controller, the classification information for classifying that the data portion of the packet is encrypted.

78. A copy protection apparatus, comprising:

a receiving unit configured to receive encrypted digital data to be recorded, key information which is required to decrypt the encrypted digital data, and first copy control information which indicates a copy permission status of the encrypted digital data;

a recording unit configured to record the encrypted digital data, the key information, and second copy control information on a digital recording medium; and

a controller operably coupled to the recording unit, to determine at least a status of the first copy control information, and to allow the recording unit to record the encrypted digital data based on the determined result, the received encrypted digital data being partitioned into a plurality of first data units, each of which includes a header portion and a data portion respectively,

wherein the recording unit is further configured to record the plurality of units, and to record the second copy control information in the header portion followed by the data portion in at least one first data unit, under control of the controller.

99. The apparatus of claim 78, wherein said recording unit is further configured to record the encrypted digital data only when the first copy control information indicates that a copy is permitted.

100. The apparatus of claim 99, wherein said recording unit includes an encrypting unit configured to encrypt the key information and said recording unit is further configured to record the encrypted key information in a control area followed by the encrypted digital data, under control of the controller.

101. The apparatus of claim 99, wherein the second copy control information indicates that the copy has been generated, and

wherein the recording unit is further configured to record an identifier to identify that the second copy control information is included, under control of the controller.

102. The apparatus of claim 99, wherein the recording unit is further configured to record classification information to classify the encrypted digital data, under control of the controller.

79. A copy protection apparatus, comprising:

a providing unit configured to provide digital content, key information for controlling at least decryption of the digital content, and copy control information for controlling copying of the digital content;

a partitioning unit configured to partition the provided digital content into a plurality of first data units;

a recording unit configured to record the key information, the copy control information and the partitioned digital content on a digital recording medium; and

a controller, operably coupled to the recording unit, to control the recording operation,

wherein the digital content is partitioned into a GOP (Group Of Picture) unit, and

wherein the recording unit is further configured to record the digital content in the GOP unit, and record the copy control information in an area followed by the GOP unit, under control of the controller.

80. The apparatus of claim 79, wherein the key information provided by the providing unit is encrypted key information.

81. The apparatus of claim 80, wherein the recording unit is further configured to record the encrypted key information in a control portion followed by the digital content or in a portion of at least one of first data unit, under control of the controller.

82. The apparatus of claim 81, wherein the recording unit is further configured to record the copy control information in the control portion followed by the digital content or in a portion of at least one of first data unit, under control of the controller.

83. The apparatus of claim 80, further comprising:

an encryption circuit configured to encrypt the digital content in a predetermined encryption algorithm, the digital content being encrypted by the key information,

wherein the recording unit is further configured to record the digital content as encrypted by the encryption circuit, under control of the controller.

84. The apparatus of claim 79, wherein the recording unit is further configured to record an identifier to indicate that the copy control information is included under control of the controller, thereby identifying an existence of the copy control information.

85. The apparatus of claim 84, wherein the recording unit is further configured to record the identifier and the copy control information in a control portion followed by the digital content or in a portion of at least one offirst data unit, under control of the controller.

86. The apparatus of claim 79, wherein the recording unit is further configured to record an identifier to indicate that the copy control information is included in the portion followed by the GOP unit or the portion of at least one GOP unit, under control of the controller.

87. A copy protection apparatus, comprising:

a providing unit configured to provide digital content, key information for controlling at least decryption of the digital content, and copy control information for controlling copying of the digital content;

a partitioning unit configured to partition the provided digital content into a plurality of first data units;

a recording unit configured to record the key information, the copy control information and the partitioned digital content on a digital recording medium; and

a controller operably coupled to the recording unit, to control the recording operation, the digital content being partitioned into one or more first data units, the first data unit being partitioned into one or more second data units, the second data unit including a header portion and a data portion,

wherein the recording unit is further configured to record the copy control information in the header portion followed by the data portion in at least one second data unit, under control of the controller.

88. The apparatus of claim 87, wherein the recording unit is further configured to record an identifier to indicate that the copy control information is included, under control of the controller.

89. The apparatus of claim 87, wherein the recording unit is further configured to record the key information in a control data portion followed by a first of the first data units, under control of the controller.

90. A copy protection apparatus, comprising:

a retrieving circuit configured to retrieve a digital data, the digital data including encrypted digital content, first key information for decrypting the encrypted digital content, and copy control information which indicates whether or not a copy of the encrypted digital content is permitted; and

a control circuit configured to control a reproducing of the encrypted digital content from a recording medium based on the first key information and/or the copy control information, the digital data being partitioned into one or more first data units, the first data unit including a header portion and a data portion, the encrypted digital content being included in the data portion and the copy control information being included in the header portion followed by the data portion.

91. The apparatus of claim 90, further comprising:

a decrypting circuit configured to decrypt the data portion including the encrypted digital content based on the first key information.

92. The apparatus of claim 91, wherein the decrypting circuit is configured to decrypt the first key information based on second key information, and then decrypt the encrypted digital content based on the decrypted first key information.