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US 5,757,909 AGranted
Illegal view and copy protection method in digital video system and controlling method thereof
AssigneeLG Electronics Inc.
InventorTae Joon Park
Life of this patent
Estimating the term…
Abstract
Illegal view and copy protection method in a digital video system for preventing an illegal user from viewing the digital video system and copying therefrom, by setting a descrambling method which decrypts split keystreams adopting a smart card, including a determination step for determining received data of having been scrambled; a reproduction step, a recording step, and a transporting step, wherein the reproduction step, the recording step and the transporting step can be performed simultaneously or selectively.
Claims35
An illegal view and copy protection method in a digital video system comprising:
- a determination step for determining received data of having been scrambled;
- a reproduction step, if the received data was determined to be scrambled data in the determination step, splitting the scrambled data into a bitstream and a keystream for decrypting the split keystream for reading in key information, and descrambling the split bitstream according to the read in key information for displaying the bitstream on a display;
- a recording step for, if the received data was determined to be scrambled data in the determination step, recording the scrambled data on a recording medium either as scrambled data of a bitstream and a keystream according to a recording or copying mode, or after splitting the scrambled data into a bitstream and a keystream, encrypting the split keystream, and mixing the encrypted keystream with the bitstream;
- and
- a transporting step, if the received data was determined to be scrambled data in the determination step, splitting the scrambled data into a bitstream and a keystream for transporting the split keystream either after decrypting the split keystream with respect to key information from recording side according to a pay-per-copy mode or a back-up copy mode, or after decrypting the split keystream two times with respect to key information of said keystream's and key information from recording side;
- thereby the reproduction step, the recording step and the transporting step can be performed simultaneously or selectively.
3 more elements
An illegal view and copy protection method in a digital video system comprising:
- a reproduction step, on reception of scrambled data, splitting the scrambled data into a bitstream and a keystream for decrypting the split keystream for reading in key information, and descrambling the split bitstream according to the read in key information for displaying the bitstream on a display;
- and,
- a recording step for, on reception of scrambled data, recording the scrambled data on a recording medium as scrambled data of a bitstream and a keystream;
- thereby the reproduction step and the recording step can be performed simultaneously or selectively.
1 more element
An illegal view and copy protection method in a digital video system on reception of a keystream encrypted with respect to said keystream's key information at copying, comprising:
- a determining step for determining the mode of the keystream being a back-up copy mode or a pay-per-copy mode;
- a first transportation step for, if the mode was determined to be a PPC mode in the determining step, decrypting the keystream with respect to key information from a recording side for transporting the keystream;
- a first recording step for encrypting the keystream transported in the first transportation step with respect to the key information from the recording side and inserting the encrypted keystream into a position corresponding to an index code, for recording the keystream together with a bitstream on a recording medium;
- a second transportation step for, if the mode was determined to be a back-up copy mode in the determining step, decrypting the keystream for two times with respect to said keystream's key information and the key information from the recording side for transporting the keystream;
- and
- a second recording step for encrypting the keystream transported in the second transportation step with respect to the key information from the recording side and inserting the encrypted keystream into the position corresponding to the index code, for recording the keystream together with the bitstream on a recording medium.
3 more elements
An illegal view and copy protection method in a digital video system, comprising:
- a pay-per-copy mode reproduction step for having determined the recording medium being a pay-per-copy recording medium on detection of a keystream at reproduction from a recording medium, encrypting the keystream with respect to said keystream's key information and decrypting the keystream with respect to said keystream's key information for reading in the key information, for descrambling the bitstream using both the read in key information and an index code;
- and,
- a `back-up copy` mode reproduction step for, having determined the recording medium being a `back-up copy` recording medium on detection of a keystream decrypted with respect to said keystream's key information at reproduction from a recording medium, encrypting the keystream for two times with respect to said keystream's key information and the key information from a recording side and decrypting the keystream with respect to said keystream's key information for reading in the key information, for descrambling the bitstream using both the read in key information and an index code.
An illegal view and copy protection device in a digital video system, comprising:
- demodulating & error correcting means for demodulating a broadcasting signal and Reed Solomon decoding said signal;
- copy protection processing means for transporting the output of said demodulating & error correcting means to a digital recording/reproduction device, splitting the scrambled recording signal reproduced from said digital recording/reproduction device into a bitstream and a keystream, and encrypting the split keystream;
- decoding means for descrambling the bitstream from said demodulating & error correcting means or the copy protection processing means according to descrambling information;
- and,
- a smart card for decrypting the encrypted keystream of said copy protection processing means for applying to said decoding means as descrambling information.
2 more elements
An illegal view and copy protection device in a digital video system comprising:
- first copy protection processing means for splitting reproduction data from a first digital recording/reproduction device into a bitstream and a keystream and encrypting the split keystream;
- first and second smart cards for decrypting encrypted keystream from said first copy protection processing means with respect to said keystream's key information and the key information from a recording side;
- and,
- second copy protection processing means for encrypting the keystream from the first smart card transported through the second smart card with respect to said keystream's key information and transporting the encrypted keystream together with the split bitstream to a second digital recording/reproduction device, for recording on a recording medium.
1 more element
Dependencies are inferred from the claim text.