A copy prevention method and apparatus of a digital magnetic recording/reproducing system performs the copy prevention function by encoding to insert a marker involving copy prevention function information and executing the function and allows a program supplier to realize a desired copy prevention function of various patterns, in which the marker formed by a control word for scrambling audio and video bit straps and copy prevention information for preventing an illegal copy is encrypted by an encoded key to be multiplexed with the audio and video bit strips scrambled by the control word. The marker transmitted is detected from the bit strips to be decrypted and analyzed by the encoded key to determine whether the copy is permitted or not, so that the detected marker is updated to be recorded on a video tape and the control word is produced from the marker to perform the descrambling to supply the result to a monitor to be displayed. Thus, the program supplier selects the copy prevention function, and a separate format converting apparatus is not required since a field defined within a GA format is utilized while an existing DVCR is not need to be changed for performing the copy prevention function as the data amount to be recorded is not increased. A method and apparatus for transmitting digital data are discussed. According to an embodiment, the invention is directed to a method of transmitting digital data using a data processing apparatus including a scrambler, the method comprising: scrambling, by the scrambler, one or more data units included in the digital data based on control data, the digital data including a first data block and one or more succeeding data blocks, each data block including a header and one data unit, at least the header in the first data block including the control data, wherein the first data block and the one or more succeeding data blocks are scrambled based on the control data included in the first data block; and transmitting, by the data processing apparatus, the one or more scrambled data units and the control data, the control data being used for controlling a parameter of a scrambling/descrambling operation.

Patent
   RE44121
Priority
Dec 08 1994
Filed
Jan 07 2009
Issued
Apr 02 2013
Expiry
Dec 01 2015
Assg.orig
Entity
Large
17
103
EXPIRED
0. 39. A method of transmitting digital data using a data processing apparatus including a scrambler, the method comprising:
generating control data for initializing the scrambler;
initializing the scrambler based on the control data directly input into the scrambler;
scrambling, using the same initialized scrambler and the same control data, both digital audio data and digital video data;
generating a first 188 byte data block including a header with the control data used to initialize the scrambler and a scrambled data portion including the scrambled digital audio and/or digital video data;
generating at least a second 188 byte data block including the scrambled digital audio and digital video data and not including the control data;
determining if a minimum of a multiple of four 188 byte data blocks have been scrambled;
determining if a timing point that includes a decimal fraction of 0.66 control words per second (CW/s) has passed since a previous initialization of the scrambler;
re-initializing the scrambler based on a new control word when the determining steps determine either the minimum of the multiple of four 188 byte data blocks have been scrambled or the timing point that includes the decimal fraction of 0.66 control words per second (CW/s) has passed since the previous initialization of the scrambler; and
transmitting, by the data processing apparatus, the generated first data block and the at least second data block.
0. 42. An apparatus for transmitting digital data, comprising:
a processor; and
a memory connected to the processor and including executable instructions that when executed by the processor, cause the processor to perform:
generating control data for initializing the scrambler; initializing the scrambler based on the control data;
scrambling, using the same initialized scrambler and the same control data, both digital audio data and digital video data;
generating a first 188 byte data block including a header with the control data used to initialize the scrambler and a scrambled data portion including the scrambled digital audio and/or digital video data;
generating at least a second 188 byte data block including the scrambled digital audio and digital video data and not including the control data;
determining if a minimum of a multiple of four 188 byte data blocks have been scrambled;
determining if a timing point that includes a decimal fraction of 0.66 control words per second (CW/s) has passed since a previous initialization of the scrambler;
re-initializing the scrambler based on a new control word and based on the determination that either the minimum of the multiple of four 188 byte data blocks have been scrambled or the timing point that includes the decimal fraction of 0.66 control words per second (CW/s) has passed since the previous initialization of the scrambler; and
transmitting the generated first 188 byte data block and the at least second 188 byte data block.
0. 1. A copy prevention method of a digital magnetic recording/reproducing system comprising:
an audio and video signal transmitting process 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 said marker with said audio and video bit strips scrambled by said control word, and
an audio and video signal receiving/recording process of detecting said marker from said transmitted bit strips, decrypting and analyzing the detected marker by means of an encoded key to determine whether copy is permitted or not, updating said detected marker to be recorded on a video tape, and generating said control word from said marker to perform a descrambling and supply the audio and video signals to be displayed on a monitor.
0. 2. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 1, wherein said marker is placed on a transport-private-data field within said bit strips.
0. 3. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 2, wherein said marker is comprised of a copy prevention information area recorded with said copy prevention information for preventing said illegal copy, and a control word area recorded with said control word for descrambling.
0. 4. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 3, wherein said marker is formed of 8 bytes.
0. 5. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 4, wherein said copy prevention area is formed of one byte.
0. 6. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 4, wherein said control word area is formed of four bytes.
0. 7. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 3, wherein said copy prevention information is formatted by including a generational copy control field for restricting the number of permitting said copy of a program.
0. 8. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 7, wherein said generational copy control field comprises:
an allowable generational field for restricting the copy number of said program; and
a current generational field representing a current generation of a duplicated program.
0. 9. A copy prevention-method of a digital magnetic recording/reproducing system as claimed in claim 1, wherein said audio and video transmitting process comprises:
an audio and video bit-strip encoding step of encoding said audio and video bit strips;
a control word generating step of generating said control word for scrambling;
a scrambling step for scrambling said encoded audio and video bit strips by means of said generated control word;
a copy prevention information generating step of generating said copy prevention information for preventing said illegal copy;
a marker generating and encrypting step of generating said marker by means of said generated control word and copy prevention information and encrypting said marker by means of said encoded key; and
a multiplexing and transmitting step of multiplexing to transmit said scrambled audio and video bit strips and encrypted marker.
0. 10. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 1, wherein said audio and video signal receiving/recording process comprises:
a marker detecting step of demultiplexing said transmitted bit strips to detect said marker, and decrypting said marker by means of said encoded key;
a marker analyzing step of analyzing said detected marker to determine whether said copy is permitted or not, and detecting said control word;
an audio and video decoding step of descrambling and decoding said transmitted audio and video bit strips by means of said detected control word, and outputting said audio and video signals; and
a marker inserting step of updating said detected marker and encrypting said updated marker by means of said encoded key to insert the result when it is determined that said copy is permitted after analyzing said marker.
0. 11. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 10, wherein said marker analyzing step comprises:
a copy prevention information detecting step of detecting said copy prevention information for preventing said illegal copy from said detected marker;
a copy number restricting step of comparing an allowable generation of said allowable generational field and a current generation of said current generational field representing said current generation for restricting the number of permitting said copy of said program within said detected copy prevention information, and determining whether said copy is permitted or not-to process the result; and
a control word detecting step of detecting said control word for descrambling from said detected marker.
0. 12. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 11, wherein said copy number restricting step comprises:
comparing said allowable generation of said allowable generational field with said current generation of said current generational field to determine whether said allowable generation is below said current generation;
inhibiting said copy when it is determined that said allowable generation is below said current generation; and
permitting said copy when it is determined that said allowable generation is-not below said current generation, and proceeding to said marker inserting step.
0. 13. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 12, wherein said step of inhibiting said copy is performed by destructing said control word or impeding an output of said control word to block a reproduction after recording.
0. 14. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 10, wherein said control word is periodically changed.
0. 15. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 14, wherein said control word is changed in the interval of 0.6 second.
0. 16. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 14, wherein said marker is placed on said transport-private-data field within said bit strips whenever said control word is changed.
0. 17. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 16, wherein said marker inserting step comprises the steps of:
updating said marker when the analysis of said marker determines to permit said copy;
encrypting said updated marker by means of said encoded key; and
replacably inserting said encrypted marker with a succeeding marker.
0. 18. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 1, wherein said encoded key is transported via a separate transmission line to be stored.
0. 19. A copy prevention method of a digital magnetic recording/reproducing system as claimed in claim 18, wherein said encoded key is transported via said separate transmission line for a prescribed time interval.
0. 20. A copy prevention apparatus of a digital magnetic recording/reproducing system comprising:
an encrypted marker detecting and inserting part for detecting a marker from input bit strips, and inserting an updated marker to said bit strips to output the result;
a marker analyzing and processing part for decrypting and analyzing the encrypted marker from said marker detecting and inserting part by means of an encoded key, outputting a control word for descrambling said bit strips, and updating and encrypting the decrypted marker by means of said encoded key to output the result;
a buffer part for buffering said control word and updated and encrypted marker from said marker analyzing and processing part, and inserting said updated and encrypted marker in said marker detecting and inserting part; and
a descrambler for descrambling said bit strips provided via said marker detecting and inserting pant by means of said control word from said buffer part.
0. 21. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 20, wherein said encoded key is transported via a separate transmission line to be stored.
0. 22. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 21, wherein said encoded key is transported via said separate transmission line for a prescribed time interval.
0. 23. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 20, wherein said marker is placed on a transport-private-data field within said bit strips whenever said control word is changed.
0. 24. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 23, wherein said marker is comprised of a copy prevention information area recorded with said copy prevention information for preventing said illegal copy, and a control word area recorded with said control word for descrambling.
0. 25. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 24, wherein said marker is formed of 8 bytes.
0. 26. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 25, wherein said copy prevention area is formed of one byte.
0. 27. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 25, wherein said control word area is formed of four bytes.
0. 28. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 24, wherein said copy prevention information is formatted by including a generational copy control field for restricting the copy number of a program.
0. 29. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 28, wherein said generational copy control field comprises:
an allowable generational field for restricting the number of permitting the copy of a program; and
a current generational field representing a current generation of a duplicated program.
0. 30. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 20, wherein said control word is periodically changed.
0. 31. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 30, wherein said control word is changed in the interval of 0.6 second.
0. 32. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 30, wherein said marker is placed on a transport-private-data field within said bit strips whenever said control word is changed.
0. 33. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 30, wherein said marker detecting and inserting part replacably inserts said updated marker with a succeeding marker.
0. 34. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 20, wherein said marker detecting and inserting part comprises:
a marker detecting section for detecting to output said encrypted marker from said input bit strips to said marker analyzing and processing part, outputting a marker detection flag signal for informing of the position of said encrypted marker within said bit strips to said descrambler to be used as a reference signal of initializing said descrambler, and outputting said bit strips; and
a marker inserting section for inserting said updated and encrypted marker from said buffer part to said bit strips from said marker detecting section in accordance with said marker detection flag signal from said marker detecting section to output the result to said descrambler.
0. 35. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 24, wherein said marker analyzing and processing part comprises:
a marker decoding section for decrypting said encrypted marker from said marker detecting and inserting part by means of said encoded key;
a marker analyzing section for analyzing said copy prevention information within said marker from said marker decoding section, and outputting said control word to said buffer part and a control signal for updating said marker when said copy is permitted; and
a marker updating and encoding section for updating said marker from said marker decoding section in accordance with said control signal from said marker analyzing section, and encrypting said updated marker by means of said encoded key to output the result to said buffer part.
0. 36. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 35, wherein said marker analyzing and processing part further comprises an encoded key storage section for storing said encoded key to output it to said marker analyzing section and marker updating and encoding section.
0. 37. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 35, wherein said marker analyzing section compares an allowable generation of an allowable generational field with a current generation of a current generational field representing a current generation of a duplicated program to determine whether said copy is permitted or not.
0. 38. A copy prevention apparatus of a digital magnetic recording/reproducing system as claimed in claim 20, wherein said buffer part comprises:
a marker buffer for temporally storing said updated and encrypted marker from said marker analyzing and processing part, and outputting the result to said marker detecting and inserting part; and
a control word buffer for temporally storing said control word from said marker analyzing and processing part, and outputting the result to said descrambler.
0. 40. The method of claim 39, wherein the scrambling step does not scramble the header in the first 188 byte data block.
0. 41. The method of claim 43, further comprising
identifying the number of times the digital data has been copied and/or the number of times permitted to copy the digital data, based on copy prevention information included in the header of the first data block, wherein the copy prevention information includes at least one of current generation information and allowable generation information, the current generation information indicating the number of times the digital data has been copied and the allowable generation information indicating the number of times permitted to copy the digital data.
0. 43. The apparatus of claim 42, wherein the executable instructions further cause the processor to perform:
not scrambling the header in the first 188 byte data block.
0. 44. The apparatus of claim 42, wherein the executable instructions further cause the processor to perform:
identifying the number of times the digital data has been copied and/or the number of times permitted to copy the digital data, based on copy prevention information included in the header of the first data block, the copy prevention information including at least one of current generation information and allowable generation information, the current generation information indicating the number of times the digital data has been copied and the allowable generation information indicating the number of times permitted to copy the digital data.
0. 45. The apparatus of claim 42, wherein the executable instructions further cause the processor to perform:
determining whether the digital data requires a copy prevention function based on identification information included in the header of the first data block, the identification information indicating whether or not at least a portion of the digital data has a data structure for copy prevention, and the controller is further configured to detect copy prevention information for controlling the copy prevention function from the digital data according to a result of this determination.
0. 46. The method of claim 39, further comprising:
determining whether the digital data requires a copy prevention function based on identification information included in the header of the first data block, the identification information indicating whether or not at least a portion of the digital data has a data structure for copy prevention; and
detecting copy prevention information for controlling the copy prevention function from the digital data according to a result of this determining step.

magnetic recording/reproducing system according to the present invention emphasizes a fact that a DVCR can record all diverse signals on a video tape, so that a variety of input signals are largely classified into two, and different use a copy prevention methods are performed for each signal method based on the type of input signal.

First, signals transmitted from a terrestrial broadcasting system, a satellite broadcasting system and a pay television broadcasting system are classified as a broadcasting signal signals, and the following three copy prevention functions are applicable when recording the a broadcasting signal.

Three The three copy prevention functions are a no recording onto a video tape permitted, a free record/copy onto the tape, and a single generational recording onto the tape with no copy of the recorded tape.

Here, the third copy prevention function of the single generational recording onto the video tape with no duplication of the recorded tape is for enabling the signal from a television receiver to record on the tape be recorded once but inhibiting the re-recording of the signal by means of another, for example, a DVCR is prohibited while the firstly-recorded tape signal can be reproduced to watch through a monitor.

A second classification is for, for example, a rental tape to be identified by a pretaped signal. Here, the copy prevention function of the pretaped signal is similar to the above no recording onto the tape and the free record/copy onto the tape copy protection function, which and has the following three copy protection functions.

The three functions are no copy onto another tape, free copy to another tape and a single generational copy to another tape.

The single generational copy function to the other tape is of the copy prevention function for allowing a allows duplication from the original rental tape, but inhibiting inhibits another copy from the duplication, which is utilized in a digital audio tape (DAT) duplicate.

The present invention is advantageous in that a program supplier selects the above functions when providing a program. For this purpose, the program supplier inserts desired copy prevention function information, i.e., a marker, into a predetermined field within the program.

The marker inserted to transport data by the program supplier prior to being transmitted is encoded, and, in order to impede an illegal copy, an encoding key for interpreting the marker is transferred via a separate transmission line such as telephone line by a prescribed period interval, e.g., once a month, to be stored within a copy prevention apparatus.

In a system having an ATV decoder incorporated in a body with, for example, the DVCR in a body, a copy prevention apparatus for embodying the copy prevention functions executes a digital copy prevention function during an interface process between the ATV decoder and the DVCR, and. The copy prevention apparatus decodes and determines the marker of a received program by means of a received encoded encoding key to perform another function in accordance with respective copy prevention functions.

The copy prevention method of the digital magnetic recording/reproducing system according to the present invention is performed through an audio and video signal transmitting process as shown in FIG. 1, and an audio and video signal receiving and recording process as shown in FIG. 2.

The audio and video signal transmitting process is for encrypting the marker formed by a control word for scrambling audio and video bit strips and copy prevention (hereinafter simply referred to as “CP”) information for preventing an illegal duplication by means of an encoded key to multiplex and transmit the audio and video bit strips scrambled by the control word. Here, the marker is already formed by a program producer to be multiplexed and transmitted together with the audio and video bit strips.

In more detail, as shown in FIG. 1, the audio and video signal transmitting process is carried out in the sequence of an audio/video bitstrip encoding step 1 for encoding the audio and video bit strips, a control word generating step 2 for generating the control word for scrambling, and a scrambling step 6 for scrambling the encoded audio and video bit strips by means of the generated control word. Successively, a CP information generating step 3 generates the CP information for preventing the illegal copy, and marker producing and encrypting. steps 4 and 5 generates respectively generate the marker by using the generated control word and CP information and encrypts encrypt the resulting marker by means of the encoded an encoding key. Finally, a multiplexing and transmitting step 7 multiplexes the scrambled audio and video bit strips and encrypted marker to transmit the result.

The audio and video signal receiving and recording process is performed in such a manner that the marker is detected from the transmitted bit strips and is decrypted by means of the encoded encoding key and analyzed. Thus, it is determined whether the copy is permitted or not to update the detected marker to be recorded on a video tape, the detected marker is updated accordingly, and the control word is produced from the marker to carry out the descrambling and display the signals on a monitor. As a result, in which the audio and video signals transmitted from the program producer are recorded or displayed in accordance with the marker.

More specifically, as shown in FIG. 2, shows the audio and video signal receiving and recording process is performed by in detail. As shown, the process includes marker detecting steps 11 and 12 for detecting the marker by demultiplexing the transmitted bit strips, and decrypting the marker by means of the encoded encoding key, and a marker analyzing step 13 for analyzing the detected marker to determine whether the a copy is permitted or not and for detecting the control word. Then, the transmitted audio and video bit strips are descrambled and decoded by using the detected control word to supply the audio and video signals in audio and video decoding steps 14 and 15. Thereafter, the detected marker is updated and encrypted by means of the encoded encoding key to be inserted in case of permitting the copy after analyzing the marker in a and reinserted in the transmitted audio and video bit strips in marker inserting steps 16, 17 and 18 if copying is permitted.

The above-stated process will be described in detail below.

To begin with, the program producer encodes the audio and video bit strips 1, generates the control word for scrambling 2, and scrambles the encoded audio and video bit strips by means of the generated control word 6.

Also, the CP information for preventing the illegal copy is generated 3, and the marker is generated by using the generated control word and CP information 4, and the coded key is utilized to perform the encryption 5.

Finally, the scrambled audio and video bit strips and encrypted marker are multiplexed 7 to be transmitted for the program recording or reproduction.

The transmitted bit strips are demultiplexed to detect the marker 11, and the encoded. The encoding key is utilized to perform the decryption and the decrypted marker is output 12. The detected and decrypted marker is analyzed to determine whether the copy is permitted or not and the control word is detected 13.

The detected control word is used for descrambling and decoding the transmitted audio and video bit strips to provide the audio and video signals to the monitor to be displayed for display 14 and 15.

In addition, when it is determined that the a copy is permitted after analyzing the marker, the detected marker is updated to be encrypted, re-encrypted by means of the encoded encoding key, and the result is inserted to the audio and video bit strips to be recorded 16, 17 and 18.

Here, a position of inserting the marker will be observed with reference to FIG. 3.

The transmitted bit strips consists consist of transport packets of a fixed length, i.e., 188 bytes, in which a transport header is displaced on the preceding stage of the bit strips. The transport header is divided into a field of a fixed length of 4 bytes and an adaptation field of a variable length. Then, a transport-private-data field exists as one field within the adaption field. The transport-private-data field consists of an ID field and the encrypted marker. The ID field functions as a an identifier for informing that the transport-private-data field is a field utilized for the copy prevention method according to the present invention, and the encrypted marker following the ID field embodies the copy prevention function of the present invention.

When the marker is decrypted by means of the encoded encoding key, the decrypted marker is divided into a CP information area recorded with including the CP information for preventing the illegal copy, a control word area recorded with including the control word CW for descrambling, and a reserved area.

That is, the decrypted marker is formed of 8 bytes consisting of the CP information area of one byte, the reserved area of three bytes and control word area of four bytes.

At this time, the CP information is formatted by including a generational copy control field which restricts the number of permitting the copy permitted copies of the program, which. The generational copy control field is formed of an allowable generational field for limiting the copy number of the program and a current generational field representing a current generation of the duplicated program.

Next, the marker analyzing step 13 of the audio and video receiving and recording process will be described in detail.

The marker analyzing step 13 is carried out by the CP information detecting step of detecting the CP information for preventing the illegal copy from the detected marker, a copy number limiting step of comparing the allowable generation of the allowable generational field for restricting the number of permitting the copy of the program and the current generation of the current generational field representing the current generation of the duplicated program within the detected CP information to determine whether the copy is permitted or not, and the control word detecting step of detecting the control word from the detected marker for executing the descrambling.

In other words, the CP information for preventing the an illegal copy is detected from the detected marker, and the allowable generation of the allowable generational field for limiting the copy number of the program is compared with the current generation of the current generational field representing the current generation of the duplicated program within the detected CP information to determine whether the copy is permitted or not, so that the program is recorded in case of permitting the copy, otherwise the. Otherwise, reproduction cannot be executed in case of inhibiting the copy, even though the recording is attained.

Next, the control word for descrambling is detected from the detected marker.

Here, the step of limiting the copy number is carried out by comparing the allowable generation of the allowable generational field with the current generation of the current generational field to determine whether the allowable generation is the current generation, inhibiting the copy when it is determined that the allowable generation is below the current generation, and permitting the copy when it is determined that the allowable generation is not below the current generation to proceed to the marker insertion step.

The copy number limiting step will be described below.

When the allowable generation is below the current generation after comparing the allowable generation of the allowable generational field preset by the program producer with the current generation of the current generational field representing the current copy number, the copy number exceeds the copy number preset by the program producer. Thus, the copy cannot be further copying cannot be permitted.

At this time, in order to inhibit the copy, the control word is destructed or is not output to block the, which blocks reproduction after performing of the copy. This is because the audio and video bit strips are recorded under the state of being scrambled, the scrambled audio and video bit strips cannot be descrambled without the control word.

Therefore, by destructing the control word, the reproduction and display cannot be achieved even though the audio and video bit strips are recorded to; thereby have having the same effect of as impeding the recording of them.

At this time, since the control word is periodically changed in the of an interval of 0.6 second, the reproduction is impeded by destructing the succeeding control word even after accomplishing the recording.

Also, a control track within the video tape may be destructed to inhibit the copy when the recording medium is a video tape.

On the other hand, the marker is positioned on the private data field within the bit strips whenever the control word is changed.

Here, since the control word is periodically changed, the marker including the control word is received whenever the control word is changed to be supplied.

Meantime, the marker inserting step is performed by updating the marker when the copy is permitted after analyzing the marker 16, encrypting the updated marker by means of the encoded key 17, and replacing the encrypted marker with the following marker to be inserted 18.

In other words, if the copy is permitted after analyzing the marker, the current generation of the current generational field is augmented by one to update the marker 16. That is, the CP information including the updated current generational field obtained by augmenting the current generation by one is summed with the control word to be the updated marker.

The updated marker is encrypted by means of the encoded key to be replaced with encoding key and is inserted to replace the succeeding marker and inserted 17. More specifically, as the marker is supplied whenever the control word is changed, it is inserted whenever the control word is changed.

In other word words, as shown in FIG. 3, the detection of the encrypted marker and the replacement of the updated marker should be accomplished altogether on time basis.

Meanwhile, the encoded encoding key for encrypting and decrypting the marker is transmitted via a separate transmission line in a predetermined time interval and is stored to be utilized, thereby perfectly preventing the illegal copy.

That is, the marker encrypted by the encoded encoding key is transmitted and recorded together with the bit strips. Here, the control word for descrambling the scrambled audio and video bit strips is included in the marker, so that the marker should be primarily decrypted to obtain the control word. However, since the encoded encoding key for decrypting the marker is periodically changed, it is impossible to decrypt the marker without the encoded encoding key. Accordingly, it is further difficult to illegally obtain the control word.

As shown in FIG. 4, the copy prevention apparatus of the digital magnetic recording/reproducing system according to the present invention includes a marker detecting/inserting section 21, a descrambler 24, a marker analyzing/processing section 22 and a buffer section 23.

Marker detecting/inserting section 21 detects the marker from the received bit strips, and inserts to output the updated marker, i.e., the updated and encrypted marker, from buffer section 23 to the bit strips.

Marker analyzing/processing section 22 utilizes the encoded key encoding keys to decrypt and analyze the encrypted marker from marker detecting/inserting section 21, thereby providing the control word CW for descrambling the bit strips. Then, the decrypted marker is updated and encrypted by the encoded encoding key to be for output.

Buffer section 23 buffers control word CW and the updated and encrypted marker IEM from marker analyzing/processing section 22, so that the updated and encrypted marker IEM is supplied to be inserted in marker detecting/inserting section 21.

Descrambler 24 descrambles the bit strips output via marker detecting/inserting section 21 by means of the control word CW from buffer section 23 to supply the result to the monitor to be displayed or to, for example, a DVCR to record the bit strips inserted with the marker.

Here, the encoded encoding key is transmitted via the separate transmission line in at a predetermined time interval and is stored as the copy prevention method of the digital magnetic recording/reproducing system according to the present invention to double a copyright protection effect.

Referring to FIG. 3, the structure of the transport bit strips and marker will be described prior to describing the operation of the copy prevention apparatus of the digital magnetic recording/reproducing system constructed as above.

In the copy prevention apparatus of the digital magnetic recording/reproducing system, the marker is placed on the transport-private-data field within the bit strips, and the CP information area recorded with the CP information for preventing the illegal copy and the control word area recorded with the control word CW for descrambling are included thereto as shown in FIG. 3, like the copy prevention method.

Here, the CP information is formatted by including the generational copy control field for restricting the number of permitted copies of the program, which is formed of the allowable generational field for limiting the copy number of the program and the current generational field representing the current generation of the duplicated program.

The marker is formed of 8 bytes consisting of the CP information area of one byte and control word area of four bytes.

Hereinbelow, an operation of the copy prevention apparatus of the digital magnetic recording/reproducing system according to the present invention will be briefly described with reference to FIG. 4.

First, a process of displaying the input bit strips on the monitor will be described.

The input bit strips are supplied to marker analyzing/processing section 22 under the state that the marker is detected and encrypted in marker detecting/inserting section 21.

Encrypted marker EM is decrypted by means of the encoded encoding key to be analyzed in marker analyzing/processing section 22. At this time, the control word is detected from the analyzed marker to be buffered via buffer section 23 for descrambling the bit strips and is supplied to descrambler 24.

The bit strips, after detecting the detection of the marker in marker detecting/inserting section 21, are descrambled in descrambler 24 in accordance with the control word from buffer section 23, and provided to the monitor to be displayed for display.

Next, a process of recording the input bit strips via, for example, the DVCR will be described.

The process of detecting and analyzing the marker from the input bit strips is executed in the same manner.

That is, the input bit strips is are supplied to marker analyzing/processing section 22 under the state that the marker is detected and encrypted decrypted in marker detecting/inserting section 21.

Encrypted marker EM is decrypted by means of the encoded encoding key in marker analyzing/processing section 22 to detect the control word. At this time, the recording can be performed or not in accordance with the result of the analysis. If the recording is not permitted, the detected control word is destructed to impede the reproduction even though the recording can be attained. Otherwise, the current generation of the current generational field within the marker is augmented by one to update the marker, so that the encoded encoding key is utilized to encrypt the marker to supply, and the result is supplied to buffer section 23.

The updated and encrypted marker is buffered in buffer section 23 and is supplied to marker detecting/inserting section 21 to be inserted to the input bit strips.

Meantime, the control word is periodically changed in the interval of 0.6 second, and the marker is placed on the transport-private-data field within the bit strips whenever the control word is changed.

Consequently, the updated and encrypted marker is replaced with replaces the succeeding marker to be inserted.

The bit strips inserted with the updated and encrypted marker pass through descrambler 24 intact and are output to be recorded in the DVCR.

The detailed construction and operation of the copy prevention apparatus in the digital magnetic recording/reproducing system formed as above will be described with reference to the accompanying drawings.

FIG. 5 is a detailed construction view showing the copy prevention apparatus of FIG. 4, which will be described below.

Marker detecting/inserting section 21 includes a marker detector 31 which detects the encrypted marker from the input bit strips and supplies the detected marker to marker analyzing/processing section 22 and a marker detection flag signal for informing of the position of the encrypted marker within the bit strips to descrambler 24 to be. The flag is used as a reference signal of for initializing descrambler 24 while outputting the bit strips. In addition to marker detector 31, a marker inserter 32 inserts the updated and encrypted marker from buffer section 23 to into the bit strips from marker detector 31 in accordance with the marker detection flag signal from marker detector 31 to output the. The result is output to descrambler 24.

Marker analyzing/processing section 22 has a marker decoder 34 for decrypting the encrypted marker from marker detector 31 of marker detecting/inserting section 21 by means of the encoded encoding key, and a marker analyzer 34 for analyzing analyzes the CP information within the marker from marker decoder 34 to output the control word to buffer section 23 when the copy is permitted while outputting a control signal for updating the marker. Additionally, a marker updating/encoding unit 35 updates the marker from marker decoder 34 in accordance with the control signal from marker analyzer 34 to encrypt the marker by means of the encoded encoding key to output the result to buffer section 23.

Here, marker analyzing/processing section 22 further includes an encoding key storage unit (not shown) for storing the encoded encoding key and to output the result encoding key to marker decoder 33 and marker updating/encoding unit 35.

Besides Also, marker analyzer 34 compares the allowable generation of the allowable generational field for restricting the number of permitting the copy of the program with the current generation of the current generational field representing the current generation of the duplicated program to determine whether the a copy is permitted or not.

Buffer section 23 includes a marker buffer 36 for temporally storing the updated and encrypted marker from marker analyzing/processing section 22 to supply it to marker detecting/inserting section 21, and a control word buffer 37 for temporally storing the control word from marker analyzing/processing section 22 to supply it to descrambler 24.

An operation of the copy prevention apparatus of the digital magnetic recording system according to the present invention constructed as above will be described with reference to FIG. 6 FIGS. 6A-6G.

FIG. 6A is a timing chart of the transmitted bit strips, FIG. 6B is of illustrates the marker detection flag m-det-flag, FIG. 6C is of illustrates the control word CW(i) from marker analyzer 34, FIG. 6D is of illustrates the updated and encrypted master IEM(i) from marker updating/encoding unit 35, FIG. 6F is of illustrates the updated and encrypted marker IEM(i) from marker buffer 36, and FIG. 6G is of illustrates the control word CW(i) from control word buffer 37.

Encrypted marker EM(i) is included in the transmitted bit strips.

The transmitted bit strips including encrypted marker EM(i) is are formed as shown in FIG. 6A, which is supplied to marker detector 31 to detect encrypted marker EM(i) to be supplied to marker decoder 33. Also, marker detector 31 generates marker detection flag signal m-det-flag for informing of the position of the encrypted marker at the encrypted marker EM(i) portion as shown in FIG. 6B, so that the generated signal is supplied to marker inserter 32 together with the bit strips including encrypted marker EM(i). Also, marker detection flag m-det-flag is supplied to descrambler 24 to be utilized as the reference signal for initializing descrambler 24 by control word CW(i−1) from control word buffer 37.

Encrypted marker EM(i) is decrypted by the encoding key in marker decoder 33 to be and is supplied as decrypted marker M(i).

Decrypted marker M(i) is analyzed in marker analyzer 34 to determine whether the copy is permitted or not. In other words, marker analyzer 34 compares the CP information within decrypted marker M(i), i.e., the allowable generational field with the current generational field, and determines to permit the copy when the allowable generational field is not below the current generational field.

When the copy is permitted as above, marker analyzer 34 slightly delays control word CW(i), which is a part of decrypted marker M(i), to be supplied to control word buffer 37, as shown in FIG. 6C. At this time, marker analyzer 34 provide provides the control signal to marker updating/encoding unit 35 to control the updating of the marker.

That is, marker decoder 33 form forms decrypted marker M(i) from encrypted marker EM(i) after delaying a delay time required for the decode, and the marker analyzer 34 generates control word CW(i) from decrypted marker M(i) in marker analyzer 34.

At this time, control word CW(i) is transmitted to control word buffer 37 to be stored until it is utilized in descrambler 24.

Decrypted marker M(i) from marker decoder 33 is updated in accordance with the control signal from marker analyzer 34 in marker updating/encoding unit 35.

That is, the updated data is the data recorded on the current generational field within the marker, which is obtained by adding one to the previously recorded current generation.

The marker updated as described above is encrypted. i.e., encoded, in accordance with the encoded encoding key to be supplied to marker buffer 36 as shown in FIG. 6D, slightly delayed with respect to control word CW(i) from marker analyzer 34 as shown in FIG. 6C. In more detail, the encrypted marker M(i) from marker decoder 33 is supplied to marker updating/encoding unit 35 to be generated as marker IEM(i), which is updated and encrypted after delaying the a delay time required for the encoding to be, and marker IEM(i) is supplied to marker buffer 36.

Here, the point of generating updated and encrypted marker IEM(i) and control word CW(i) from marker updating/encoding unit 35 and marker analyzer 34 does not coincide with a point of utilizing updated and encrypted marker IEM(i) and control word CW(i) in marker inserter 32 and descrambler 24, i.e., the points of performing the replaceable insertion and initialization of descrambler 24 do not coincide with each other. Thus, updated and encrypted marker IEM(i) and control word CW(i) from marker updating/encoding unit 35 and marker analyzer 34 are temporally stored in marker buffer 36 and control word buffer 37 for that time.

As shown in FIG. 6E, updated and encrypted marker IEM(i) temporally stored in marker buffer 36 and synchronized to be output is inserted by marker inserter 32 to into the bit strips from marker detector 31.

In more detail, marker inserter 32 receives the bit strips having encrypted marker EM(i) and marker detection flag signal m-det-flag from marker detector 31, and receives updated and encrypted marker IEM(i) which will be replaceably inserted to into the position of encrypted marker EM(i) from marker buffer 36, so that updated and encrypted marker IEM(i) is replacably inserted to the position of marker detection flag signal m-det-flag in the transmitted bit strips including encrypted marker-EM(i) as shown in FIG. 6E.

In other words, marker inserter 32 inserts updated and encrypted marker IEM(i) from marker buffer 37 replacing encrypted marker EM(i+1) at the position of producing marker detection flag signal m-det-flag.

Here, the replacably inserted marker IEM(i) is formed from the immediately detected preceding encrypted marker. Accordingly, as shown in FIG. 6E, the marker IEM(i) is stored in marker buffer 37 for a certain period to be and then provided to marker inserter 32.

As shown in FIG. 6F, control word CW(i−1) is temporally stored in control word buffer 37 to be synchronized prior to being output and is utilized for descrambling the transmitted bit strips from marker inserter 32 in descrambler 24.

At this time, descrambler 24 uses marker detection flag signal m-det-flag from marker detector 31 as the reference signal for initializing based on control word CW(i−1) from control word buffer 37.

More specifically, descrambler 24 must be initialized by control word CW(i−N) from control word buffer 37 during a period from the point of generating encrypted marker EM(i), i.e., from a position of detecting marker detecting flag signal m-det-flag to the point before starting payload of a transport packet, where N is a natural number greater than zero. Here, control word CW(i−N) is a control word formed from encrypted marker EM(i−N) transmitted before encrypted marker EM(i) as many as N times. The natural number ‘N’ allows for arbitrarily controlling the initializing point of descrambler 24.

In the copy prevention method and apparatus of the digital magnetic recording/reproducing system according to the present invention as described above, a program supplier can select the copy prevention function, and the field defined within a GA format is utilized. As the result, a separate format transformation apparatus for the copy prevention function is not required, and there is no increase in data amount to be recorded to perform the copy prevention function without converting, for example, the general digital VCR.

While the present invention has been particularly shown and described with reference to particular embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be effected therein without departing from the spirit and scope of the invention as defined by the appended claims.

Park, Tae Joon

Patent Priority Assignee Title
11636654, May 19 2021 SNAP INC AR-based connected portal shopping
11863513, Aug 31 2020 Snap Inc. Media content playback and comments management
11870745, Jun 28 2022 SNAP INC ; Snap Inc. Media gallery sharing and management
11880947, Dec 21 2021 SNAP INC Real-time upper-body garment exchange
11888795, Sep 21 2020 Snap Inc. Chats with micro sound clips
11893166, Nov 08 2022 Snap Inc. User avatar movement control using an augmented reality eyewear device
11941767, May 19 2021 Snap Inc. AR-based connected portal shopping
11983462, Aug 31 2021 SNAP INC Conversation guided augmented reality experience
12062144, May 27 2022 Snap Inc. Automated augmented reality experience creation based on sample source and target images
12062146, Jul 28 2022 SNAP INC ; Snap Inc. Virtual wardrobe AR experience
12080065, Nov 22 2019 SNAP INC Augmented reality items based on scan
12086916, Oct 22 2021 Snap Inc. Voice note with face tracking
12094066, Mar 30 2022 Snap Inc. Surface normals for pixel-aligned object
12100156, Apr 12 2021 Snap Inc. Garment segmentation
ER3054,
ER4137,
ER8658,
Patent Priority Assignee Title
3753228,
4420829, Jan 08 1981 Holographic system for the storage of audio, video and computer data
4554461, Dec 24 1982 Hitachi, Ltd. Information transmitting apparatus
4694489, Dec 22 1983 Video transmission system
4736422, Jun 30 1983 Independent Broadcasting Authority Encrypted broadcast television system
4796220, Dec 15 1986 Pride Software Development Corp. Method of controlling the copying of software
4802215, Jul 23 1983 Independent Broadcasting Authority Security system for television signal encryption
4817140, Nov 05 1986 International Business Machines Corp. Software protection system using a single-key cryptosystem, a hardware-based authorization system and a secure coprocessor
4871140, May 20 1988 Moore Push-Pin Company Hanging device
4890319, Sep 21 1984 Scientific-Atlantic, Inc. Method for controlling copying of protected information transmitted over a communications link
4916738, Nov 05 1986 International Business Machines Corp. Remote access terminal security
4924513, Sep 25 1987 HEWLETT-PACKARD DEVELOPMENT COMPANY, L P Apparatus and method for secure transmission of data over an unsecure transmission channel
4937679, Aug 11 1986 Macrovision Dual deck video recording apparatus having enhanced copy protection and method for providing enhanced copy protection to such a recording apparatus
4965680, Jun 30 1987 Kabushiki Kaisha Toshiba Apparatus for releasing a restriction on the recording of an information signal on a recording medium
4975952, Sep 04 1985 U. S. Philips Corporation Method of data communication
4999806, Sep 04 1987 Software distribution system
5003590, Dec 18 1989 Eidak Corporation Encoding an optical video disc to inhibit video tape recording
5014274, Apr 08 1988 Victor Company of Japan, Ltd. Code-error correcting device
5034981, Apr 11 1988 EIDAK CORPORATION, A CORP OF DE Anti-copying video signal processing
5034985, Nov 13 1989 Pitney Bowes Inc. Matched mailing system employing address print array recognition
5054064, Mar 29 1990 Verizon Laboratories Inc Video control system for recorded programs
5057947, Feb 10 1988 MATSUSHITA ELECTRIC INDUSTRIAL CO , LTD , Recording and reproducing apparatus with limited digital copying
5058162, Aug 09 1990 Hewlett-Packard Company Method of distributing computer data files
5073925, Jul 08 1987 Matsushita Electric Industrial Co., Ltd. Method and apparatus for the protection of signal copy
5109413, Nov 05 1986 International Business Machines Corporation Manipulating rights-to-execute in connection with a software copy protection mechanism
5134656, Feb 22 1989 NAGRA PLUS S A Pre-payment television system using a memory card associated with a decoder
5138659, May 02 1991 GENERAL INSTRUMENT CORPORATION GIC-4 Conversion of television signal formats with retention of common control data stream
5144658, Nov 24 1989 Sharp Kabushiki Kaisha Repeater of digital audio interface signal
5159633, Jan 19 1990 Canon Kabushiki Kaisha Multimedia network system
5182680, Feb 26 1990 Sony Corporation Recording control system
5193176, Oct 17 1990 POWERCARD SUPPLY, L C Computer work saving during power interruption
5231546, Feb 10 1988 Matsushita Electric Industrial Co., Ltd. Recording and reproducing apparatus with limited digital copying
5233650, Mar 03 1989 Sun Plan Investments Limited Telephone support device
5243650, Mar 23 1990 Televerket Method and apparatus for encryption/decryption of digital multisound in television
5260999, Jun 28 1991 HEWLETT-PACKARD DEVELOPMENT COMPANY, L P Filters in license management system
5265164, Oct 31 1991 INTERNATIONAL BUSINESS MACHINES CORPORATION A CORP OF NEW YORK Cryptographic facility environment backup/restore and replication in a public key cryptosystem
5289276, Jun 19 1992 General Electric Company Method and apparatus for conveying compressed video data over a noisy communication channel
5303294, Jun 18 1991 Matsushita Electric Industrial Co., Ltd. Video theater system and copy preventive method
5315448, Mar 18 1993 Macrovision Corporation Copy protection for hybrid digital video tape recording and unprotected source material
5323244, Sep 24 1992 Matsushita Electric Industrial Co., Ltd. Recording and reproducing apparatus
5377266, Jul 21 1992 MATSUSHITA ELECTRIC INDUSTRIAL CO , LTD Scramble apparatus and descramble apparatus
5381481, Aug 04 1993 Cisco Technology, Inc Method and apparatus for uniquely encrypting a plurality of services at a transmission site
5392351, Mar 16 1992 Fujitsu Limited Electronic data protection system
5406625, Nov 22 1991 Sony Corporation Receiving apparatus and recording method
5418853, Jul 24 1992 Sony Corporation Apparatus and method for preventing unauthorized copying of video signals
5442541, Jul 23 1993 Xerox Corporation Enabling features over common communication channel
5469272, Mar 05 1991 Sony Corporation Digital signal recording and/or reproducing apparatus
5477276, Dec 17 1992 Sony Corporation Digital signal processing apparatus for achieving fade-in and fade-out effects on digital video signals
5504816, Feb 02 1994 Google Technology Holdings LLC Method and apparatus for controlling access to digital signals
5506903, Apr 06 1993 Sony Corporation Digital multiplex transmission system
5513260, Jun 29 1994 Macrovision Corporation Method and apparatus for copy protection for various recording media
5530756, Sep 15 1993 U S PHILIPS CORPORATION Television scrambling and descrambling method, and transmitter and receiver using said method
5546461, Apr 09 1993 MATSUSHITA ELECTRIC INDUSTRIAL CO , LTD Scramble system for use in digital video signal recording and reproducing system or transmission and receiving system, comprising scramble apparatus and descramble apparatus
5563946, Apr 25 1994 ACTIVISION PUBLISHING, INC Method and apparatus for enabling trial period use of software products: method and apparatus for passing encrypted files between data processing systems
5574787, Jul 25 1994 Macrovision Corporation Apparatus and method for comprehensive copy protection for video platforms and unprotected source material
5576843, Oct 29 1993 WARNER BROS HOME ENTERTAINMENT INC System and method for controlling play of multiple dialog audio tracks of a software carrier
5579120, Oct 08 1993 Sony Corporation Copyright protection for digital signal recording and/or reproduction and recording medium thereof
5583562, Dec 03 1993 Cisco Technology, Inc System and method for transmitting a plurality of digital services including imaging services
5588058, Mar 31 1993 U S PHILIPS CORPORATION Method and device for scrambling and descrambling of a specific television broadcast
5590306, Sep 08 1992 FUJIFILM Corporation Memory card management system for writing data with usage and recording codes made significant
5629980, Nov 23 1994 CONTENTGUARD HOLDINGS, INC System for controlling the distribution and use of digital works
5638513, Dec 22 1993 STAMPS COM, INC Secure software rental system using continuous asynchronous password verification
5646992, Sep 23 1993 MICROSEMI FREQUENCY AND TIME CORPORATION Assembly, distribution, and use of digital information
5659613, Jun 29 1994 Macrovision Corporation Method and apparatus for copy protection for various recording media using a video finger print
5673357, Feb 15 1994 Sony Corporation Video recording, transmitting and reproducing apparatus with concurrent recording and transmitting or multiple dubbing of copy protected video signals
5689559, Dec 08 1994 LG Electronics Inc Copy prevention method and apparatus of a digital magnetic recording/reproducing system
5689561, Oct 06 1995 Computer-based trading card system and method
5703859, Sep 01 1995 Sony Corporation Digital video copy protection system
5715403, Nov 23 1994 CONTENTGUARD HOLDINGS, INC System for controlling the distribution and use of digital works having attached usage rights where the usage rights are defined by a usage rights grammar
5757909, Nov 26 1994 LG ELECTRONICS, INC Illegal view and copy protection method in digital video system and controlling method thereof
5757910, Apr 06 1993 LG ELECTRONICS, INC Apparatus for preventing illegal copying of a digital broadcasting signal
5761302, Nov 26 1994 LG Electronics Inc Copy prevention method and apparatus for digital video system
5778064, Mar 31 1995 Sony Corporation Apparatus and method for processing a high definition video signal
5790664, Feb 26 1996 GraphOn Corporation Automated system for management of licensed software
5799081, Sep 18 1995 LG Electronics Inc. Illegal view/copy protection method and apparatus for digital broadcasting system
5832084, Nov 10 1995 LG Electronics, Inc. Recording method of digital magnetic recording medium for copyright protection and variable speed playback
5862115, Nov 30 1993 JVC Kenwood Corporation Method and apparatus for recording an information signal with scrambling thereof
5881038, Feb 27 1994 Matsushita Electric Industrial Co., Ltd. Method and apparatus for preventing illegal copy or illegal installation of information of optical recording medium
5898695, Mar 29 1995 Hitachi Maxell, Ltd Decoder for compressed and multiplexed video and audio data
5907443, May 30 1990 Canon Kabushiki Kaisha Recording and reproducing apparatus adapted to selectively control the number of copies made
5910987, Feb 13 1995 INTERTRUST TECHNOLOGIES CORP Systems and methods for secure transaction management and electronic rights protection
5925127, Apr 09 1997 Microsoft Technology Licensing, LLC Method and system for monitoring the use of rented software
5956505, Dec 24 1991 Pitney Bowes Inc. Remote activation of software features in a data processing device
6009401, Apr 06 1998 SAFENET DATA SECURITY ISRAEL LTD Relicensing of electronically purchased software
6028932, Nov 26 1994 LG Electronics Inc. Copy prevention method and apparatus for digital video system
6052242, Jun 07 1989 Canon Kabushiki Kaisha Recording apparatus with copy control based on copies made and allowed to be made
6236971, Nov 23 1994 CONTENTGUARD HOLDINGS, INC System for controlling the distribution and use of digital works using digital tickets
6430290, Jan 23 1998 Koninklijke Philips Electronics N V Conditional access
7069250, Oct 15 2001 CUFER ASSET LTD L L C Check based online payment and verification system and method
7114745, Dec 10 2002 TRW Automotive Safety Systems GmbH Monitoring system for detent connections
CN1085723,
EP267039,
EP498617,
EP519320,
EP580367,
EP581227,
EP589459,
JP6162690,
JP6199288,
JP6339110,
JP670282,
RE33189, May 09 1988 Comsat Corporation Security system for SSTV encryption
RE36763, Jul 24 1992 Sony Corporation Apparatus and method for preventing unauthorized copying of video signals
/
Executed onAssignorAssigneeConveyanceFrameReelDoc
Jan 07 2009LG Electronics Inc.(assignment on the face of the patent)
Date Maintenance Fee Events
Aug 23 2013ASPN: Payor Number Assigned.


Date Maintenance Schedule
Apr 02 20164 years fee payment window open
Oct 02 20166 months grace period start (w surcharge)
Apr 02 2017patent expiry (for year 4)
Apr 02 20192 years to revive unintentionally abandoned end. (for year 4)
Apr 02 20208 years fee payment window open
Oct 02 20206 months grace period start (w surcharge)
Apr 02 2021patent expiry (for year 8)
Apr 02 20232 years to revive unintentionally abandoned end. (for year 8)
Apr 02 202412 years fee payment window open
Oct 02 20246 months grace period start (w surcharge)
Apr 02 2025patent expiry (for year 12)
Apr 02 20272 years to revive unintentionally abandoned end. (for year 12)