Cryptography – Video cryptography – Copy protection or prevention
Reissue Patent
1998-06-12
2001-02-13
Laufer, Pinchus M. (Department: 2766)
Cryptography
Video cryptography
Copy protection or prevention
C380S239000, C360S060000, C705S057000, C386S349000
Reissue Patent
active
RE037052
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a copy prevention method and apparatus of a digital
magnetic
recording/reproducing system, and more particularly to a copy prevention method and apparatus of a digital
magnetic
recording/reproducing system, wherein a marker involving copy prevention function information and executing the function is coded and inserted to perform the copy prevention function and realize the copy prevention function of various patterns desired by a program supplier.
2. Description of the Prior Art
One example of a conventional copy prevention method is described in U.S. Pat. No. 4,819,098, in which a signal inducing an interference to an automatic gain controller (AGC) circuit within a VCR is inserted to a video waveform to be recorded on a tape. When the tape is reproduced to display the signal on a television, the interference signal does not affect the AGC circuit of the television
to allow
, allowing
for a normal display.
However, when the reproduced signal is recorded by another VCR, i.e., when it is duplicated, the interference signal brings about
the
interference in the AGC circuit of the
recording
VCR
to record in
causing
an inaccurate signal level
to be recorded
. Accordingly, the nodal display cannot be attained when reproducing a duplicated tape.
As another example, U.S. Pat. No. 4,571,642 utilizes a control track employed during performing the reproduction for synchronizing a servo circuit within a VCR,
thereby
for
embodying the copy prevention function. The basic concept of this patent is for altering a video signal to force the control track to be inaccurately recorded when the video signal is duplicated onto another tape.
Still another example is disclosed in U.S. Pat. No. 4,577,216, in which a phase noise or the like is inserted
to
in
a chroma burst portion of a video signal to thereby embody the copy prevention function.
The above-mentioned methods
are for using
using
a difference
of
between the
sensitivity
between
of
circuits
of
in
a television and
of
a VCR.
Thus, the copy prepared to prevent the copy thereof as above may not exert the copy prevention function in a certain VCR, but may not execute a normal display on a certain television.
The above copy prevention methods are of an analog system, which are available for preventing the copy of an NTSC-class video signal to an analog VCR. However, in case of a high-definition image of the analog television (ATV), the copy is performed by means of a digital VCR rather than an analog VCR, so that it is difficult to employ the copy prevention method of the analog system.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide a copy prevention method and apparatus of a digital
magnetic
recording/reproducing system
applicable
to a digital VCR and incorporated with various copy prevention functions to enable the selection of a copy prevention function desired by a program supplier.
To achieve the above object of the present invention, there is provided a copy prevention method of a digital magnetic recording/reproducing system, which is performed by an audio and video signal transmitting process and an audio and video signal receiving/recording process. The audio and video signal transmitted process is carried out in the sequence of encrypting a marker formed by a control word for scrambling audio and video bit strips and copy prevention information for preventing an illegal copy by means of an encoding key, and multiplexing the marker with the audio and video bit strips scrambled by the control word. Then, the audio and video signal receiving/recording process is performed in the sequence of detecting the marker from the transmitted bit strips, decrypting and analyzing the detected marker by means of an encoded key to determine whether
copy
copying
is permitted or not, updating the detected marker to be recorded on a video tape, and generating the control word from the marker to perform a descrambling and supply the audio and video signals to be displayed on a monitor.
Also, a copy prevention apparatus of a digital magnetic recording/reproducing system includes a marker detecting and inserting part for detecting a marker from input bit strips, and inserting the updated marker to the bit strips to output the result. A marker analyzing and processing part decrypts and analyzes the encrypted marker from the marker detecting and inserting part by means of an encoded key, outputs a control word for descrambling the bit strips, and updates and encrypting the decrypted marker by means of the encoded key to output the result. In addition, a buffer part buffers the control word and updated and encrypted marker from the marker analyzing and processing section, and inserts the updated and encrypted marker in the marker detecting and inserting part, and a descrambler descrambles the bit strips provided via the marker detecting and inserting part by means of the control word from the buffer part.
These and other objects are achieved by providing a method of copy protecting digital data, comprising generating copy prevention information; generating control data; scrambling digital data based on said control data; forming a marker, said marker including said copy prevention information and said control data; and transmitting said scrambled digital data and said marker.
These and other objects are further achieved by providing a method of processing copy protected digital data, comprising receiving digital data said digital data including copy prevention information; determining from said copy prevention information whether copying is permitted; updating said copy prevention information if said determining step determines that a copy is permitted; inserting said updated copy prevention information in place of said copy prevention information only in said digital data for recording; and recording output from said inserting step.
These and other objects are still further achieved by providing an apparatus for copy protecting digital data, comprising a copy prevention generator generating copy prevention information; a control data generator generating control data; a scrambler scrambling digital data based on said control data; marker forming means for forming a marker, said marker including said copy prevention information and said control data; and a transmitting unit transmitting said scrambled digital data and said marker.
In an alternative embodiment, the scrambled digital data and the marker are recorded.
These and other objects are still further achieved by providing an apparatus for processing copy protected digital data, comprising a receiving unit receiving digital data, said digital data including copy prevention information; an analyzing unit determining from said copy prevention information whether copying is permitted, and updating said copy prevention information if a copy is permitted; an inserting unit inserting said updated copy prevention information in place of said copy prevention information only in said digital data for recording; and a recording unit recording output from said inserting unit.
REFERENCES:
patent: 4694489 (1987-09-01), Frederiksen
patent: 4890319 (1989-12-01), Seth-Smith et al.
patent: 5057947 (1991-10-01), Shimada
patent: 5231546 (1993-07-01), Shimada
patent: 5418853 (1995-05-01), Kanota et al.
patent: 5575787 (1996-11-01), Ryan
patent: 5579120 (1996-11-01), Oguro
patent: 5588058 (1996-12-01), Le Berre
patent: 5659613 (1997-08-01), Copeland et al.
patent: 5673357 (1997-09-01), Shima
patent: 5799081 (1998-08-01), Kim et al.
patent: 5907443 (1999-05-01), Hirata
Laufer Pinchus M.
LG Electronics Inc.
LandOfFree
Copy prevention method and apparatus of a digital... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Copy prevention method and apparatus of a digital..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Copy prevention method and apparatus of a digital... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2580274