Copy prevention method and apparatus for digital video system

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.

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 content protection method for a digital data system including a controller and an encryption device, the method comprising:
 receiving first key information by the encryption device within the digital data system, the first key information for encrypting digital content, the digital content including one or more data segments, the one or more data segments including a header portion and a data portion, wherein at least the data portion is encrypted using the first key information and the header portion includes classification information to classify the data portion;   encrypting, via the controller controlling the encryption device, the first key information using second key information that is different than the first key information; and   transferring the encrypted first key information with the controller.   
     
     
       33. The method of claim 32, wherein the second key information is a public key, such that said encrypting step encrypts the first key information using the public key. 
     
     
       34. The method of claim 32, wherein said transferring step includes recording the encrypted first key information on a digital storage medium. 
     
     
       35. The method of claim 32, wherein said transferring step also transmits the encrypted digital content. 
     
     
       36. An apparatus for content protection, comprising:
 an encryption device programmed to receive first key information, the first key information for encrypting digital data, and programmed to encrypt the first key information using second key information that is different than the first key information, wherein the digital data includes one or more data segments, the one or more data segments including a header portion and a data portion, wherein at least the data portion is encrypted using the first key information and the header portion is not encrypted and the header portion includes classification information to classify the data portion; and   a controller, coupled to the encryption unit, and programmed to control the encryption operation and control a transfer of the encrypted first key information.   
     
     
       37. The apparatus of claim 36, wherein the second key information is a public key, such that said encryption device is programmed to encrypt the first key information using the public key. 
     
     
       38. The apparatus of claim 36, wherein said controller is programmed to control recording of the encrypted first key information and encrypted digital data on a digital storage medium. 
     
     
       39. The apparatus of claim 36, wherein said controller is also programmed to control a transmitting of the encrypted digital data. 
     
     
       40. A content protection method within a digital data system including a controller and a generating device, the method comprising:
 generating, via the controller controlling the generating device, protected digital content, the protected digital content including one or more data segments, the one or more data segments including a header portion and a data portion, wherein at least the data portion is protected and the header portion includes classification information to classify the protected digital content; and   transmitting, via the controller, the protected digital content and first key information used to generate the protected digital content,   wherein the first key information is required to process the protected digital content in a receiving part and is encrypted using second key information different than the first key information.   
     
     
       41. The method of claim 40, further comprising:
 encrypting the first key information using the second key information prior to said transmitting step.   
     
     
       42. The method of claim 41, wherein the second key information is a public key, such that the first key information is encrypted using the public key. 
     
     
       43. The method of claim 40, wherein the generating step includes encrypting the digital content by a block-cipher algorithm or a stream-cipher algorithm. 
     
     
       44. A content protection method for a digital data system including a controller, a recording device and an encryption device, the method comprising:
 receiving first key information by the encryption device within the digital data system, the first key information for encrypting digital data, the digital data including a header portion and a data portion;   encrypting, via the controller controlling the encryption device, the first key information using second information;   encrypting, via the controller controlling the encryption device, the digital data using the first key information, wherein only the data portion is encrypted; and   recording, via the controller controlling the recording device, the encrypted first key information and the encrypted digital data on a digital medium,   wherein the header portion includes classification information to classify the encrypted data portion on a digital medium.   
     
     
       45. The method of claim 44, wherein the second information is a public key, such that the first key information is encrypted using the public key. 
     
     
       46. The method of claim 44, wherein the header portion and the data portion comprise a packet. 
     
     
       47. The method of claim 44, wherein the first key information is randomly generated. 
     
     
       48. A content protection method for a digital data system including a controller, a receiving circuit and a decryptor, the method comprising:
 (a) receiving encrypted digital content and encrypted first key information by the receiving circuit within the digital data system, the first key information being previously used for encrypting the digital content, the digital content including a header portion and a data portion, wherein only the data portion is encrypted;   (b) decrypting, via the controller controlling the decryptor, the first key information using second information; and   (c) decrypting, via the controller controlling the decryptor, the encrypted digital content using the decrypted first key information,   wherein the header portion includes classification information to classify the digital content, and   the step (a) includes classifying the digital content based on the classification information by the controller.   
     
     
       49. The method of claim 48, wherein the second information is a public key such that the first key information is decrypted by the public key. 
     
     
       50. The method of claim 48, wherein said step (c) decrypts the encrypted digital content only when the first key information is normally decrypted in step (b). 
     
     
       51. A content protection method within a digital data system for content protection including a controller and a receiving circuit, the method comprising:
 receiving protected digital content and key information which is required to process the protected digital content by the receiving circuit, wherein the protected digital content includes one or more data segments, the one or more data segments including a header portion and a data portion, wherein at least a portion of the header portion is non-protected; and   processing, via the controller, the protected digital content, based on the received key information,   wherein the header portion includes classification information to classify the digital content, and   the receiving step includes classifying the digital content based on the classification information by the controller.   
     
     
       52. The method of claim 51, wherein the received key information is encrypted, and
 wherein the processing step includes processing the encrypted key information by the processor.   
     
     
       53. The method of claim 52, wherein the protected digital content is processed only when the encrypted key information is normally decrypted. 
     
     
       54. The method of claim 53, wherein the encrypted key information is decrypted using second key information. 
     
     
       55. An apparatus for content protection, comprising:
 a receiving device to receive encrypted digital content and key information, wherein the encrypted digital content includes one or more data segments, the one or more data segments including a header portion and a data portion, wherein at least a portion of the header portion is non-encrypted;   a key detecting device to detect the key information; and   a controller to control a decryption process of the digital content based on the detected key information,   wherein the header portion includes classification information to classify the digital content, and   the controller is to classify the digital content based on the classification information.   
     
     
       56. The apparatus of claim 55, wherein the key information is first key information, and wherein said key detecting device is to decrypt the first key information using second key information. 
     
     
       57. The apparatus of claim 56, wherein said controller is to decrypt the data portion of each data segment using the decrypted first key information. 
     
     
       58. The apparatus of claim 55, wherein said controller is to decrypt the data portion of each data unit using the detected first key information. 
     
     
       59. The apparatus of claim 55, wherein the first key information was encrypted and predetermined by a digital data system. 
     
     
       60. An apparatus for content protection, comprising:
 a generating device to generate protected digital content, the protected digital content including one or more data segments, the one or more data segments including a header portion and a data portion, wherein at least the data portion is protected and the header portion includes classification information to classify the protected digital content; and   a controller to transmit the protected digital content and first key information used to generate the protected digital content,   wherein the first key information is required to process the protected digital content in a receiving part and is encrypted using second key information different than the first key information.   
     
     
       61. The apparatus of claim 60, further comprising:
 an encryption device to encrypt the first key information using the second key information prior to said transmission.   
     
     
       62. The apparatus of claim 61, wherein the second key information is a public key. 
     
     
       63. The apparatus of claim 61, wherein the controller is to control the encryption device to protect the digital content by a block-cipher algorithm or a stream-cipher algorithm. 
     
     
       64. An apparatus for content protection, comprising:
 a receiving device to receive first key information, the first key information for encrypting digital data, the digital data including a header portion and a data portion;   an encryption device to encrypt the first key information using second information, and encrypt the digital data using the first key information, wherein only the data portion is encrypted;   a recording device to record the encrypted first key information and the encrypted digital data on a digital medium; and   a controller, coupled to the encryption device and the recording device, to control the encryption operation and the recording operation,   wherein the header portion includes classification information to classify the encrypted data portion, and   wherein the controller is to classify the encrypted data portion based on the classification information.   
     
     
       65. The apparatus of claim 64, wherein the second information is a public key, and the encryption device is to encrypt the first key information using the public key. 
     
     
       66. The apparatus of claim 64, wherein the header portion and the data portion comprise a packet. 
     
     
       67. The apparatus of claim 64, wherein the first key information is randomly generated. 
     
     
       68. An apparatus for content protection, comprising:
 a receiving device to receive encrypted digital content and encrypted first key information, the first key information being previously used for encrypting the digital content, the digital content including a header portion and a data portion, wherein only the data portion is encrypted;   a decryption device to decrypt the first key information using second information and decrypt the encrypted digital content using the decrypted first key information; and   a controller, coupled to the receiving unit and the decryption unit, to control the decryption operation,   wherein the header portion includes classification information to classify the digital content, and   wherein the controller is to classify the digital content based on the classification information received from the receiving device.   
     
     
       69. The apparatus of claim 68, wherein the second information is a public key. 
     
     
       70. The apparatus of claim 68, wherein said controller is to control the decryption device to decrypt the encrypted digital content only when the first key information is normally decrypted. 
     
     
       71. An apparatus for content protection, comprising:
 a receiving device to receive protected digital content and key information required to process the protected digital content, wherein the protected digital content includes one or more data segments, the one or more data segments including a header portion and a data portion, wherein at least the header portion is non-protected;   a processor to process the protected digital content, using the received key information; and   a controller, coupled to the receiving device and the processor, to control the processing of the protected digital content,   wherein the header portion includes classification information to classify the digital content, and   wherein the controller is to classify the digital content based on the classification information received from the receiving unit.   
     
     
       72. The apparatus of claim 71, wherein the received key information is an encrypted key information. 
     
     
       73. The apparatus of claim 72, wherein the controller is to control the processor to process the protected digital content only when the encrypted key information is normally decrypted.