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 held 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 and a recording device, the copy protection method comprising:
 providing, via the generating device, encrypted key information, encrypted digital content, an identifier and copy prevention information, the encrypted digital content being encrypted by the encrypted key information, the encrypted key information required for at least decryption of the encrypted digital content, the identifier identifying an existence or a location of the copy prevention information and the copy prevention information indicating whether or not copying of the encrypted digital content is permitted, wherein the encrypted digital content is partitioned into a plurality of data segments, each of which includes a header portion and a data portion respectively, and wherein the copy prevention information and the identifier are included in the header portion followed by the data portion, and the encrypted digital content is included in the respective data portions; and   recording, via the recording device, the encrypted key information, and the plurality of data segments on a digital recording medium.   
     
     
       33. The method of claim 32, wherein the copy prevention information is updated prior to said recording step, and wherein said recording step records the encrypted digital content only when the copy prevention information before the update indicates that a copy of the encrypted digital content is permitted. 
     
     
       34. The method of claim 32, wherein said recording step includes recording the encrypted key information in a control area followed by an area for recording the encrypted digital content. 
     
     
       35. A copy protection method for a copy protection apparatus including a generating device and a recording device, the copy protection method comprising:
 providing, via the generating device, encrypted key information, encrypted digital content, an identifier and copy prevention information, the encrypted digital content being encrypted by the encrypted key information, the encrypted key information required for at least decryption of the encrypted digital content, the identifier identifying an existence or a location of the copy prevention information and the copy prevention information indicating whether or not copying of the encrypted digital content is permitted, wherein the encrypted digital content is partitioned into one or more GOP (Group Of Picture); and   recording, via the recording device, the encrypted key information, the encrypted digital content of GOPs, the identifier and the copy prevention information on a digital recording medium,   wherein the copy prevention information and the identifier are recorded in an area followed by the GOPs.   
     
     
       36. A recording medium to be read by a copy protection apparatus, the recording medium comprising:
 a data area including encrypted digital content;   a copy prevention information area for storing copy prevention information, which indicates whether or not a copy of the encrypted digital content is permitted; and   a key information area for storing key information, said key information for operatively controlling a decryption of the encrypted digital content,   wherein said copy prevention information area further includes an identifier to identify an existence or a location of the copy prevention information,   wherein said data area includes a plurality of first data segments, each first data segment includes a plurality of second data segments, and each second data segment comprises a header portion and a data portion, and   wherein at least the encrypted digital content is recorded in the respective data portions.   
     
     
       37. The recording medium of claim 36, wherein said key information area is followed by said data area. 
     
     
       38. The recording medium of claim 36, wherein the encrypted digital content is encrypted in packets and the packets correspond to the second data segments. 
     
     
       39. The recording medium of claim 36, wherein the key information is recorded in an encrypted format. 
     
     
       40. The recording medium of claim 36, wherein the copy prevention information is updated to indicate that a copy of the encrypted digital content has been made. 
     
     
       41. The recording medium of claim 40, wherein the updated copy prevention information indicates that no more copies of the encrypted digital content are permitted. 
     
     
       42. The recording medium of claim 36, wherein the header portion includes classification information to classify the encrypted digital content recorded in the data portion. 
     
     
       43. The recording medium of claim 36, wherein said copy prevention information area is followed by said data area or, is included in the header portion. 
     
     
       44. The recording medium of claim 43, wherein said copy prevention information area further includes an identifier to identify that the copy control information is included. 
     
     
       45. The method of claim 32, wherein the copy prevention information is variably placed within the header portion. 
     
     
       46. The recording medium of claim 43, wherein the copy prevention information is written in various locations within the header portion. 
     
     
       47. The recording medium of claim 36, wherein the header portion is not an encrypted portion while the data portion is an encrypted portion. 
     
     
       48. The method of claim 32, wherein the header portion is not an encrypted portion while the data portion is an encrypted portion. 
     
     
       49. The method of claim 35, wherein the copy prevention information is updated prior to said recording step, and wherein said recording step records the encrypted digital content only when the copy prevention information indicates that a copy of the encrypted digital content is permitted. 
     
     
       50. The method of claim 35, wherein said recording step includes recording the encrypted key information in a control area followed by an area for recording the encrypted digital content. 
     
     
       51. The method of claim 35, wherein the area followed by the GOPs is not encrypted while the GOPs is an encrypted portion. 
     
     
       52. A recording medium to be read by a copy protection apparatus, the recording medium comprising:
 a key information area for storing key information, said key information for operatively controlling a decryption of encrypted digital content; and   a data area including encrypted digital content, wherein said data area comprises a plurality of first data segments, each first data segment includes a plurality of second data segments, each second data segment comprises a header portion and a data portion, wherein at least the encrypted digital content is recorded in the respective data portions, and the header portion includes copy prevention information for indicating whether or not a copy of the encrypted digital content is permitted and an identifier for identifying a presence or a location of the copy prevention information.   
     
     
       53. The recording medium of claim 52, wherein said key information area is followed by said data area. 
     
     
       54. The recording medium of claim 52, wherein said encrypted digital content is encrypted in packets and the packets correspond to the second data segments. 
     
     
       55. The recording medium of claim 52, wherein the key information is recorded in an encrypted format. 
     
     
       56. The recording medium of claim 52, wherein the copy prevention information is updated to indicate that a copy of the encrypted digital content has been made. 
     
     
       57. The recording medium of claim 56, wherein the updated copy prevention information indicates that no more copies of the encrypted digital content are permitted. 
     
     
       58. The recording medium of claim 52, wherein the header portion further includes classification information to classify the encrypted digital content recorded in the data portion. 
     
     
       59. The recording medium of claim 52, wherein the header portion is not an encrypted portion while the data portion is an encrypted portion.