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 copy protection method for a copy protection apparatus including a generating device, an encryption device and a recording device, the method comprising:
 generating, via the generating device, copy prevention information to control a copy protection operation, the copy prevention information for indicating whether or not copying of digital data is permitted;   generating, via the generating device, identification information to indicate an existence of the copy prevention information;   encrypting, via the encrypting device, the digital data with key information while the copy protection information and the identification information is not encrypted, the key information being required to encrypt the digital data; and   recording, via the recording device, the copy prevention information, the identification information and digital data on a digital recording medium,   wherein the copy prevention information indicates at least one of “copying of digital data is permitted” and “copying of digital data is not permitted” when the identification information indicates that the copy prevention information exists, and   wherein the recording step records the identification information such that the identification information is first read to indicate the existence of the copy prevention information and is not used to control directly the copy protection operation and the copy prevention information is next read to control the copy protection operation.   
     
     
       33. The method of claim 32, further comprising:
 dividing the digital data into at least a plurality first data segments, and then recording the digital data based on the data segments.   
     
     
       34. The method of claim 33, wherein the first data segment includes a unit of at least one GOP (Group Of Picture) formed in MPEG data. 
     
     
       35. The method of claim 34, wherein the first data segment is divided into a plurality of second data segments including a header portion and a data portion, respectively. 
     
     
       36. The method of claim 35, wherein the copy prevention information and the identification information are recorded in the header portion of the second data segment. 
     
     
       37. The method of claim 33, further comprising:
 adding a header to the first data segment, the header including the identification information and the copy prevention information and the first data segment including at least one GOP (Group Of Picture), and then recording the header and first data segment on the digital recording medium.   
     
     
       38. A copy protection method for a copy protection apparatus including a receiving device, and a recording device, the method comprising:
 receiving, via the receiving device, copy prevention information which indicates whether or not copying of digital content is permitted; and   selectively recording, via the recording device, the digital content on a digital recording medium, based on a status of the received copy prevention information,   wherein recording is not performed when the copy prevention information indicates that the copy is not permitted, and recording is performed when the copy prevention information indicates that at least one copy is permitted,   wherein updated copy prevention information and identification information are further recorded on the digital recording medium when recording is performed, the identification information for indicating an existence of the copy prevention information,   wherein the updated copy prevention information indicates at least one of “copying of digital content is permitted” and “copying of digital content is not permitted” when the identification information indicates that the updated copy prevention information exists,   wherein the digital content is encrypted with key information while the copy prevention information and the identification information is not encrypted, and   wherein the identification information is recorded such that the identification information is first read to indicate the existence of the copy prevention information and is not used to control directly the copy protection operation and the copy prevention information is next read to control the copy protection operation.   
     
     
       39. The method of claim 38, wherein the updated copy prevention information indicates that no more copies are permitted. 
     
     
       40. The method of claim 39, wherein the updated copy prevention information and the identification information are written into a header followed by the digital content. 
     
     
       41. The method of claim 38, wherein the digital content is recorded as a data segment including a header portion and a data portion, and the copy prevention information and the identification information are recorded in the header portion of the digital content. 
     
     
       42. The method of claim 38, wherein the copy prevention information and the identification information are recorded in an area followed by the digital content, which is divided into a GOP (Group Of Picture). 
     
     
       43. A copy protection method for a copy protection apparatus including a reproducing device and a controller, the method comprising:
 reading, via the reproducing device, control data recorded on a digital recording medium, the control data including an identifier to indicate whether or not copy prevention information exists, wherein the copy prevention information indicates whether digital content recorded on the digital recording medium is to be copied; and   controlling, via the controller, a copy protection function based on the copy prevention information,   wherein the copy prevention information indicates at least one of “copying of digital content is permitted” and “copying of digital content is not permitted” when the identifier indicates that the copy prevention information exists,   wherein the digital content is encrypted with key information while the copy prevention information and the identifier is not encrypted, and   wherein the identifier is recorded such that the identifier is first read to indicate the existence of the copy prevention information and is not used to control directly the copy protection operation and the copy prevention information is next read to control the copy protection operation.   
     
     
       44. The method of claim 43, further comprising:
 identifying whether the copy prevention information exists based on the identifier, wherein said controlling step determines whether to perform the copy protection function according to the status of the copy prevention information.   
     
     
       45. A recording medium to be read by a copy protection apparatus, comprising:
 copy prevention information indicating whether digital content recorded on the recording medium is to be copied; and   an identifier to identify the existence of the copy prevention information,   wherein the copy prevention information indicates at least one of “copying of digital content is permitted” and “copying of digital content is not permitted” when the identifier indicates that the copy prevention information exists,   wherein the digital content is encrypted with key information while the copy prevention information and the identifier is not encrypted, and   wherein the identifier is recorded such that the identifier is first read to indicate the existence of the copy prevention information and is not used to control directly the copy protection operation and the copy prevention information is next read to control the copy protection operation.   
     
     
       46. The recording medium of claim 45, wherein the digital content is divided into a plurality of first data segments, each first data segment including a plurality of second data segments, each second data segment including a header portion and a data portion, and
 wherein the copy prevention information is included in the header portion of at least one of the second data segments.   
     
     
       47. The recording medium of claim 45, wherein the copy prevention information is followed by the digital content. 
     
     
       48. The recording medium of claim 45, wherein the digital content is divided into a plurality of first data segments, each first data segment including a plurality of second data segments, each second data segment including a header portion and a data portion, wherein the first data segment includes at least one GOP (Group Of Picture), wherein the identifier and the copy prevention information are recorded in a position followed by the GOP or are recorded in the header portion of the second data segment. 
     
     
       49. An apparatus for copy protection, comprising:
 an extractor device programmed to extract copy prevention information to control a copy protection function, the copy prevention information for indicating whether user data is to be copied; and   a controller programmed to record the user data on a digital recording medium based on the copy prevention information,   wherein the copy prevention information is extracted when identification information indicates an existence of the copy prevention information,   wherein the copy prevention information indicates at least one of “copying of user data is permitted” and “copying of user data is not permitted” when the identification information indicates that the copy prevention information exists,   wherein the user data is encrypted with key information while the copy prevention information and the identification information is not encrypted, and   wherein the identification information is recorded such that the identification information is first read to indicate the existence of the copy prevention information and is not used to control directly the copy protection operation and the copy prevention information is next read to control the copy protection operation.   
     
     
       50. The apparatus of claim 49, wherein the controller is programmed to divide the user data into at least a plurality first data segments, and then to record the user data based on the data segments. 
     
     
       51. The apparatus of claim 49, wherein the controller is programmed to determine whether the copy prevention information exists based on the identification and a status of copy prevention information when the copy prevention information exists, and to control the recording of the user data based on the status of the copy prevention information. 
     
     
       52. The apparatus of claim 51, wherein the controller is programmed to record the user data only when the copy prevention information indicates that the copy is permitted. 
     
     
       53. The method of claim 32, wherein the copy prevention information indicates at least three different copy prevention methods, and the at least three different copy preventing methods includes a no copy method preventing the digital data from being copied, a copy permitted method allowing the digital data to be freely copied, and a backup-copy-only method allowing only a backup copy of the digital data. 
     
     
       54. The method of claim 43, wherein the copy prevention information indicates at least three different copy prevention methods, and the at least three different copying methods includes a no copy method preventing the digital content from being copied, a copy permitted method allowing the digital content to be freely copied, and a backup-copy-only method allowing only a backup copy of the digital content. 
     
     
       55. The recording medium of claim 45, wherein the copy prevention information indicates at least three different copy prevention methods, and the at least three different copying methods includes a no copy method preventing the digital content from being copied, a copy permitted method allowing the digital content to be freely copied, and a backup-copy-only method allowing only a backup copy of the digital content. 
     
     
       56. The apparatus of claim 49, wherein the copy prevention information indicates at least three different copy prevention methods, and the at least three different copying methods includes a no copy method preventing the user data from being copied, a copy permitted method allowing the user data to be freely copied, and a backup-copy-only method allowing only a backup copy of the user data. 
     
     
       57. The method of claim 32, wherein the identification information indicates an address of where the copy prevention information is located. 
     
     
       58. The method of claim 57, wherein the address of the copy prevention information is variable and changes for different digital data. 
     
     
       59. The method of claim 32, wherein a recording apparatus attempting to copy the digital data first reads the identification information to determine if the copy prevention information has been generated, reads the copy prevention information when the identification information indicates the copy prevention information exists, and performs or does not perform a copying of the digital data based on the copy prevention information. 
     
     
       60. The method of claim 32, wherein the copy prevention information further includes information limiting a number of copies that can be made. 
     
     
       61. The method of claim 38, wherein the identification information indicates an address of where the copy prevention information is located. 
     
     
       62. The method of claim 61, wherein the address of the copy prevention information is variable and changes for different digital data. 
     
     
       63. The method of claim 38, wherein a recording apparatus attempting to copy the digital data first reads the identification information to determine if the copy prevention information has been generated, reads the copy prevention information when the identification information indicates the copy prevention information exists, and performs or does not perform a copying of the digital data based on the copy prevention information. 
     
     
       64. The method of claim 38, wherein the copy prevention information further includes information limiting a number of copies that can be made. 
     
     
       65. The method of claim 43, wherein the identification information indicates an address of where the copy prevention information is located. 
     
     
       66. The method of claim 65, wherein the address of the copy prevention information is variable and changes for different digital data. 
     
     
       67. The method of claim 43, wherein a recording apparatus attempting to copy the digital data first reads the identification information to determine if the copy prevention information has been generated, reads the copy prevention information when the identification information indicates the copy prevention information exists, and performs or does not perform a copying of the digital data based on the copy prevention information. 
     
     
       68. The method of claim 43, wherein the copy prevention information further includes information limiting a number of copies that can be made. 
     
     
       69. The recording medium of claim 45, wherein the identification information indicates an address of where the copy prevention information is located. 
     
     
       70. The recording medium of claim 69, wherein the address of the copy prevention information is variable and changes for different digital data. 
     
     
       71. The recording medium of claim 45, wherein a recording apparatus attempting to copy the digital data first reads the identification information to determine if the copy prevention information has been generated, reads the copy prevention information when the identification information indicates the copy prevention information exists, and performs or does not perform a copying of the digital data based on the copy prevention information. 
     
     
       72. The recording medium of claim 45, wherein the copy prevention information further includes information limiting a number of copies that can be made. 
     
     
       73. The apparatus of claim 49, wherein the identification information indicates an address of where the copy prevention information is located. 
     
     
       74. The apparatus of claim 73, wherein the address of the copy prevention information is variable and changes for different digital data. 
     
     
       75. The apparatus of claim 49, wherein a recording apparatus attempting to copy the digital data first reads the identification information to determine if the copy prevention information has been generated, reads the copy prevention information when the identification information indicates the copy prevention information exists, and performs or does not perform a copying of the digital data based on the copy prevention information. 
     
     
       76. The apparatus of claim 49, wherein the copy prevention information further includes information limiting a number of copies that can be made.