JPH08336125A - Scramble system - Google Patents

Abstract

PURPOSE: To provide a scramble system by which scrambling is applied to even a video signal recorded on a video recording and reproducing device and descrambling in video reproduction is applied only to the video signal recorded via the same STB and the reproduction of a video recording medium by a non-contractor is prevented from being performed. CONSTITUTION: A center device 100 applies the scrambling 1 and the scrambling 2 to the video signal, and transmits it with key data which cancels the scrambling 1. The STB 200 samples the key data from a demodulation signal, and outputs a signal canceling the scrambling 1 to a TV monitor by a descrambling circuit 204. While. the video signal canceling the scrambling 2 and the key data are selected by a selector 209, and outputted to a VTR. Since the scrambling 1 is applied to a recorded and reproduced video signal, the video signal is outputted to the TV monitor by canceling the scrambling 1 after collating the key data included in a reproduced video signal by a comparator 210.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scramble system for preventing illegal interception of communication or broadcasting, and more particularly to scrambling a video signal and transmitting the scrambled video signal from the center and recording and reproducing the received video image. It relates to an effective scramble system.

[0002]

2. Description of the Related Art In pay broadcasting, video signals and audio signals are scrambled in order to prevent illegal interception, and the video signal or audio signals cannot be restored unless the subscriber contracts the scramble with a descrambler. There is a system.

In a conventional scramble system,
If the scrambled video signal and the descrambling key (Key) data are received by the set top box (hereinafter abbreviated as STB) and the STB identification code (hereinafter abbreviated as STB-ID) matches The descramble key signal in the key data is used to descramble, and the descrambled video is recorded in a VTR or is monitored on a TV or the like. In addition, even if a plurality of scrambled images have the same STB-ID, descrambling is performed based on the descrambling key signal, and the VTR
The signal output to the TV or TV was in a state where all the scrambles were unscrambled.

[0004]

However, in the conventional scramble system, it is possible to record the scrambled video in the video recording / reproducing apparatus such as the VTR. Therefore, if the recorded medium is used, There was a problem that it could be viewed easily by anyone other than the contractor.

The present invention has been made in view of the above problems. An object of the present invention is to scramble the video signal recorded in the video recording / reproducing apparatus and to make the same S.
An object of the present invention is to provide a scramble system in which only a video signal recorded via TB can be descrambled during video reproduction and which prevents a non-contractor from reproducing the video recording medium.

[0006]

To achieve the above object, the present invention has the following constitution. That is, in the scramble system according to claim 1, the first scramble in which the scramble is descrambled based on the key data, and the video recording / reproduction that does not hinder the display on the video display device even if the scramble is not released A scramble system for applying a second scramble that interferes with recording and reproduction in a device to a video signal,
Transmitting means for transmitting the first and second scrambled video signals and a signal including key data for descrambling the first scramble, and the first and second scrambled video signals and Receiving means for receiving a signal containing key data for descramble of No. 1, first key extracting means for extracting the key data from the received signal, and first scrambling for descrambling based on the key data First descrambling means for outputting a demultiplexed video signal, second descrambling means for descrambling a second scramble from the received signal, the key data and the second descrambling signal And a recording signal output means for outputting a recording signal to the video recording / reproducing device, and extracting key data from the reproduction signal of the video recording / reproducing device. A second key extraction means that, the first
The key data extracted by the key extracting means and the second
Comparing means for comparing with the key data extracted by the key extracting means, if the comparison result by the comparing means is coincident, the first scramble of the reproduction signal is released, and if the comparison result is not coincident, the reproduction signal is And a control unit that does not release the first scramble.

A scramble system according to a second aspect is the scramble system according to the first aspect, wherein the first scramble is line rotation, line permutation, line translation, interference wave superimposition, synchronous compression, polarity inversion. It is a summary that it is either of.

A scramble system according to a third aspect is the scramble system according to the first aspect, wherein the second scramble is a scramble for changing a vertical synchronization phase width, and the second scramble is a scramble for a video display device. It is possible to detect vertical synchronization from an unreleased video signal, and it is impossible or difficult for the video recording / reproducing apparatus to detect vertical synchronization from an unreleased video signal. Use as a summary.

The scramble system according to a fourth aspect is the scramble system according to the first aspect, wherein the second scramble is a scramble for changing a vertical sync amplitude, and the second scramble is released in the video display device. It is possible to detect vertical synchronization from a video signal that has not been scrambled, and it is impossible or difficult for a video recording / reproducing apparatus to detect vertical synchronization from a video signal that has not been descrambling the second. And

A scramble system according to a fifth aspect is the scramble system according to the first aspect, wherein the key data includes at least a set top box identification code and a descramble key.

A scramble system according to a sixth aspect is the scramble system according to the first aspect, wherein the key data is inserted in a vertical blanking period of a video signal.

A scramble system according to a seventh aspect is the scramble system according to the first aspect, further comprising storage means for storing the key data on a receiving side.

The scramble system according to claim 8 is the scramble system according to claim 1, wherein the date recorded in the video recording / reproducing apparatus is stored in the set top box, and the recorded program is reproduced from the video recording / reproducing apparatus. The main point of this is to cancel the scramble within the specified viewing period of the program.

The scramble system according to claim 9 is the scramble system according to claim 1, wherein the key data output from the first switching means to the video recording / reproducing device is encrypted key data. The gist of the second key extracting means is that the key data is extracted by deciphering.

The scramble system according to claim 10 is the scramble system according to claim 1, wherein
It is a gist to charge a viewing fee according to a viewing period of a broadcasted program and a viewing period of playing a program recorded in a video recording / playback apparatus.

The scramble system according to claim 11 is the scramble system according to claim 1,
The gist is to charge a viewing fee according to the number of times the program recorded in the video recording / reproducing apparatus is reproduced.

[0017]

With the above structure, the scramble system according to the present invention performs the first and second scramble processing on the video signal on the transmission side, transmits the video signal together with the key data for descrambling the first scramble, and receives it on the reception side. The key data is extracted from the signal, and based on the key data, the first descramble means outputs the video signal whose first scramble is released to the video display device. The video signal that has been subjected to the second scramble is input to the video display device, but there is no problem in displaying the video even if the scramble is not released.

On the other hand, the second descrambled video signal and the first scrambled key data are output to the video recording / reproducing apparatus. Since the signal input to the video recording / playback device has been scrambled 2 so that recording / playback is not hindered, the recorded video signal itself is scrambled 1, so video recording is performed by anyone other than the contractor. The video played back from the playback device cannot be viewed.

Also, key data is extracted from the signal reproduced from the video recording / reproducing apparatus and compared with the key data extracted from the received signal, and if the comparison results are in agreement,
Recognizing that the recorded image is reproduced from the same set top box, the scramble 1 is released and the image is output to the image display device.

Further, in the present invention, the first scramble may be any one of line rotation, line permutation, line translation, interference wave superimposition, synchronous compression, and polarity inversion, and based on key data. The first scramble can be released.

Further, in the present invention, the second scramble may be a scramble for changing the vertical sync phase width or the vertical sync amplitude, and in the integration of the vertical sync separation circuit of the video display device, the vertical sync is obtained from the video signal. The second scramble is performed by selecting the vertical sync phase width or vertical sync amplitude that can be detected and for which the vertical sync cannot be detected or is difficult to integrate by the vertical sync separation circuit of the video recording / reproducing apparatus. And

Further, in the present invention, the key data includes at least a set top box identification code and a descramble key, and can identify a subscriber.

Further, in the present invention, the key data can be inserted during the vertical blanking period of the video signal to prevent the video display from being disturbed.

Further, according to the present invention, the receiving side may be further provided with a storage means for storing the key data, and the recorded key data is compared with the received key data even when it is not in a broadcasting time zone. You can

Further, in the present invention, the date recorded on the video recording / reproducing apparatus is stored in the set top box,
When the recorded program is reproduced from the video recording / reproducing apparatus, if the program is within the predetermined viewing period, the scramble is released, so that the program can be viewed only for a certain period after the broadcast.

Also, in the present invention, the key data output from the first switching means to the video recording / reproducing apparatus is encrypted key data, and the second key extracting means performs decryption. The confidentiality of the key data can be enhanced by carrying out the extraction of the key data.

Further, in the present invention, the viewing fee is charged according to the viewing period of the broadcasted program and / or the viewing period of playing the program recorded in the video recording / playback apparatus. It can be carried out.

In the present invention, the viewing fee is charged according to the number of times the program recorded in the video recording / playback apparatus is played back, so that the fee can be charged according to the number of viewing times.

[0029]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the first embodiment of the scramble system according to the present invention.

In the figure, in the center device 100, the scrambler 102 applies scramble 1 which is the first scramble to the video signal from the video signal source 101, and the scrambler 103 applies scramble 2 which is the second scramble. . Next, the key data superposition circuit 10
4, the key data 105 is superimposed, the modulator 106 modulates a predetermined carrier wave, and the modulated signal is transmitted to the transmission path 150.

On the receiving side, the STB 200, the TV monitor 250 which is a video display device, and the V monitor which is a video recording / reproducing device.
And TR260. The STB 200 includes a tuner 201, a demodulation circuit 202, a scramble 1 key extraction circuit 203, a descramble 1 circuit 204, a descramble 2 circuit 205, and a key extraction circuit 206.
A synchronization detection circuit 207, a timing generation circuit 208,
A selector 209, a key comparator 210, a key extraction circuit 211, and a switch 212 are provided.

The signal received via transmission line 150 is
Tuning, amplification, and detection are performed via the tuner 201 and the demodulation circuit 202, and the scrambled video signal is output from the demodulation circuit. This video signal is scrambled 1
Key extraction circuit 203, descramble 2 circuit 205,
It is distributed to the key extraction circuit 206 and the synchronization detection circuit 207.

The sync detection circuit 207 detects a vertical sync signal from the video signal, and based on the detected vertical sync signal, the timing generation circuit 208 extracts a key data extraction timing signal inserted in the vertical blanking period. And a timing signal for sending a key to the VTR 260 are generated and supplied to the key extraction circuit 203, the key extraction circuit 206, the selector 209 and the key extraction circuit 211 of the scramble 1.

The key extraction circuit 203 of the scramble 1
A scramble key for canceling the scramble 1 is extracted, and by using this key, the descramble 1 circuit 204 descrambles only the scramble 1 and the TV monitor 2
Output to 50. The TV monitor inputs the scrambled video signal. However, Scramble 2
As shown in FIG. 6, the vertical sync phase width is scrambled, and the vertical sync phase width is selected so that the vertical sync separation circuit of the TV monitor integrates the video signal to perform vertical sync detection. Therefore, the video reproduced on the monitor screen is not affected by the scramble 2.

On the other hand, a video signal in which only the scramble 2 is descrambled by the descramble 2 circuit 205,
A signal obtained by switching the key data extracted from the video signal by the key extraction circuit 206 by the selector 209 according to the instruction of the timing generation circuit 208 is output to the VTR 260 and recorded.

During VTR reproduction, the video signal from the VTR 260 is input to the synchronization detection circuit 207, and the timing generation circuit 208 instructs the key extraction circuit 211 on the key extraction timing based on the detected synchronization signal, and the key extraction circuit 211. At this timing, the key data is extracted from the reproduction signal of the VTR and transmitted to the key comparator 210. The key comparator 210 compares the key sent from the center extracted by the key extraction circuit 206 with the key extracted from the video signal of the VTR. If the comparison results match,
By determining that the video recorded in the VTR is reproduced through the STB and closing the switch 212,
Scramble 1 key extraction circuit 203, descramble 1
The video signal descrambled by the circuit 204 is output to the TV monitor.

If the keys are not compared in the key comparison in the key comparator 210, it is determined that the image is not the video recorded in the VTR via the STB, the switch 212 is not closed, and the scramble 1 is not released. . Further, it is clear that the scramble is not released even if the VTR tape recorded by the scramble system is reproduced by a general VTR device.

The scramble 1 here is, for example,
Line rotation (signal switching within scanning line), line permutation (scan line transition), line translation, superposition of interference waves, synchronous compression, polarity reversal for each line or frame or scene change, etc. are used.

Also, a valid viewing period is set in the key data sent from the center device 100, and the key comparator 210 compares the valid period recorded in the VTR with the current date and time. It can also be descrambled by judging whether it is in the valid period.

FIG. 2 is a block diagram showing the configuration of the second embodiment of the scramble system according to the present invention.

The structural difference between the second embodiment and the first embodiment is that the RAM for storing the STB-ID in the STB 300.
213 is added, and other configurations are
Since this is the same as the first embodiment, the same reference numerals are given and duplicate explanations are omitted.

The key extraction circuit 211 controls the VTR during VTR reproduction.
The STB-ID is extracted from the key data recorded in TR. The ID comparison circuit 210 uses the extracted STB-I.
D is compared with the STB-ID stored in the RAM 212, and if the comparison results are in agreement, it is determined that the video recorded via the STB is being reproduced by the VTR, the switch 212 is closed, and the first Similar to the embodiment, the VTR video signal is descrambled and output to the TV monitor.

As a result of the comparison in the comparison circuit 210, if they do not match, the switch 212 is not closed and descrambling is not performed. In this way, it is possible to prevent reproduction other than the VTR image recorded via the STB.

FIG. 3 is a block diagram showing the configuration of the third embodiment of the scramble system according to the present invention.

In the figure, the center device 110 scrambles the video signal from the video signal source 101 with the scrambler 103, modulates a predetermined carrier wave with the modulator 106, and sends the modulated signal to the transmission path 150. .

On the receiving side, STB 400, TV monitor 250 which is a video display device, and V which is a video recording / reproducing device.
And TR260. The STB 400 includes a tuner 201, a demodulation circuit 202, a descramble 2 circuit 205, a synchronization detection circuit 207, a timing generation circuit 208, a selector 209, an ID comparator 210, and I.
D extraction circuit 211, scramble 1 circuit 214, R
The AM 215 and the descramble 1 circuit 216 are provided.

The signal received via transmission line 150 is
Tuning, amplification, and detection are performed via the tuner 201 and the demodulation circuit 202, and the scrambled video signal is output from the demodulation circuit and sent to the TV monitor 250.

On the other hand, the video signal descrambled by the descramble 2 circuit 205 is scrambled 1 by the scramble 1 circuit 214 and supplied to the selector 209. The key data at this time is RAM
215. The RAM 215 also stores the STB-ID, and outputs the STB-ID to the selector 209 based on the timing signal from the timing generation circuit 208. The selector 209 is a timing generation circuit 20.
According to the instruction from 8, the scrambled video signal and STB-ID are selected and output to the VTR 260. Therefore, the VTR 260 records the scrambled video signal and the STB-ID. .

During VTR reproduction, the video signal from the VTR 260 is input to the sync detection circuit 207 and the STB-ID extraction circuit 211, and the timing generation circuit 208 controls the STB based on the sync signal detected by the sync detection circuit 207.
The -ID extraction timing is instructed to the STB-ID extraction circuit 211, and the STB-ID extraction circuit 211 extracts the STB-ID from the reproduced video signal of the VTR at this timing and sends it to the ID comparator 210. The ID comparator 210 is
STB extracted by STB-ID extraction circuit 211
-Compare ID with STB-ID stored in RAM 215. If the comparison results match, it is determined that the video recorded in the VTR is reproduced through the STB, and the descramble 1 circuit 216 performs scramble 1
Is released and output to the TV monitor 250.

If there is a mismatch in the comparison in the comparator 210, it is judged that the video is not recorded by VTR via the STB, and the scramble 1 is not released,
No video signal is output.

Further, it is clear that the scramble is not released even if the VTR tape recorded by this scramble system is reproduced by a general VTR device.

Although the scrambled video signal is input to the TV monitor 250, the video reproduced on the monitor screen is not affected by the scramble 2 as described in the first embodiment.

FIG. 4 is a block diagram showing the configuration of the fourth embodiment of the scramble system according to the present invention.

The difference in structure between the fourth embodiment and the first embodiment is that the scramble key, date, ST
In addition to B-ID, the period during which the video can be viewed (hereinafter,
RAM2 for storing data indicating a valid period)
18 and the charging system 217 are added.

The key extraction circuit 206 is used in the center unit 100.
Scramble key, date, STB-ID sent from
And the key data including the valid period is extracted, and the RAM 21
8 as write data. The data other than the valid period is set to V via the selector 209 as in the first embodiment.
Recorded in TR260. When playing the VTR 260,
The key data is extracted from the reproduction signal by the key extraction circuit 211 and supplied to the key comparator 219.

The key comparator 219 determines whether it is within the valid period based on the recorded date in the key data, the valid period stored in the RAM 218, and the current date.
If it is within the valid period, the switch 212 is closed so that the reproduction signal is supplied to the key extraction circuit 203 of the scramble 1, and at the same time, the charging state signal is sent to the charging system 217. If it is not within the valid period, the switch 212
Remains open and no descrambling or billing takes place.

As a modification of this embodiment, the number of times of reproduction by the VTR may be stored in the RAM 218, and the number of times may be supplied to the charging system 217 to charge the number of times of image reproduction.

FIG. 5 is a block diagram showing the configuration of the fifth embodiment of the scramble system according to the present invention.

The feature of this embodiment is that the key data extracted by the key extraction circuit 206 is subjected to a third scramble by the scramble 3 circuit 220, and then the selector 20
9 to be recorded in the VTR. As a result, the scrambled video signal and the scrambled key data are recorded in the VTR. VT
At the time of R reproduction, the scramble key extraction circuit 221 extracts the key of the scramble 3 and the descramble 3 circuit 222
The key data is descrambled and is supplied to the key comparison circuit 210. Other processes are the same as in the first embodiment.

Next, a method of extracting key data common to the above embodiments will be described with reference to FIGS. 8 and 9. As shown in FIG. 8, the key data is inserted in the 21st line within the vertical blanking period. The key extraction circuit is shown in FIG.
Using the horizontal sync signal of the first line as a reference, the data clock reproduction clock signal shown in FIG. 7B is generated, and the data clock is synchronized during this period. Then, the data clock signal (c) synchronized with the received signal is used to sample the data signal (d) to determine the logical value of each data bit.

The preferred embodiment has been described above.
This does not limit the invention. For example, the scrambled video signal may be an analog signal or a digital signal, and the video recording / reproducing apparatus may use an analog V signal.
The recording / reproducing apparatus is not limited to TR. Further, scrambling for changing the vertical synchronization phase width or the vertical synchronization amplitude can be variously modified as shown in the waveform example in FIG.

[0063]

As described above, according to the present invention,
The scrambled video signal and key data are VT
Recorded in R, VTR that does not go through the STB of the contractor
This has the effect of preventing playback and preventing viewing by other than the contractor and copying of the recording medium.

Further, it is possible to set a period during which the recorded video can be viewed, and to charge the payout based on the valid period or the number of times the VTR is played for each program to charge the payout based on the number of views. -The effect that it is possible to respond to the per view (PPV).

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of a scramble system according to the present invention.

FIG. 2 is a block diagram showing a configuration of a second embodiment of a scramble system according to the present invention.

FIG. 3 is a block diagram showing a configuration of a scramble system according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a scramble system according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing the configuration of a fifth embodiment of the scramble system according to the present invention.

FIG. 6 is a waveform diagram illustrating an example of a video signal in which the vertical scrambling phase width is changed, which is the second scramble, and vertical sync separation.

FIG. 7 is a waveform diagram showing another embodiment of changing the vertical synchronization phase width.

FIG. 8 is a waveform diagram illustrating key data inserted in a vertical blanking period.

FIG. 9 is a timing chart illustrating an operation of extracting key data inserted in a vertical blanking period.

[Explanation of symbols]

100 center device 101 video signal source 102
Scrambler 1 103 Scrambler 2 104 Multiplex circuit 10
5 key data 106 modulator 150 transmission path 200 STB 201 tuner 202
Demodulator 203 Scramble 1 key extraction circuit
204 descramble 1 circuit 205 descramble 2 circuit 206 key extraction circuit 207 synchronization detection circuit 208 timing generation circuit 209 selector 210 key comparator 211 key extraction circuit 212
Descramble control circuit 250 TV monitor
260 VTR

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Wataru Kuroiwa 8 Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Prefecture

Claims (11)

[Claims] 1. A first scramble in which the scramble is released based on the key data, and a display in the video display device is not hindered even if the scramble is not released, and a recording / playback in the video recording / playback device is performed if the scramble is not released. A scramble system for applying a disturbed second scramble to a video signal, the transmission including transmitting the video signal subjected to the first and second scramble processing and a signal including key data for descrambling the first scramble. Means for receiving the video signal subjected to the first and second scramble processing and a signal including key data for descrambling the first scramble; and a means for extracting the key data from the received signal. 1
Key extracting means, first descrambling means for outputting the first descrambled video signal based on the key data, and second descrambling means for descrambling the second signal from the received signal. Scrambling means, recording signal output means for outputting a recording signal to the video recording / reproducing apparatus by combining the key data and the second descrambled signal, and key data from the reproduction signal of the video recording / reproducing apparatus. A second key extracting means for extracting the key data, a comparing means for comparing the key data extracted by the first key extracting means with the key data extracted by the second key extracting means, and the comparing means. If the comparison results match, the first scramble of the reproduction signal is released, and if the comparison results do not match, the first scrambling of the reproduction signal is not released. Scrambling system characterized by comprising a control means. 2. The scramble system according to claim 1, wherein the first scramble is one of line rotation, line permutation, line translation, interference wave superposition, synchronous compression, and polarity inversion. . 3. The second scramble is a scramble for changing a vertical sync phase width, and the video display device can detect the vertical sync from a video signal in which the second scramble is not released. 2. The scramble system according to claim 1, wherein it is impossible or difficult for the video recording / reproducing apparatus to detect the vertical synchronization from the video signal in which the second scramble is not released. 4. The second scramble is a scramble for changing a vertical sync amplitude, and the video display device can detect the vertical sync from a video signal in which the second scramble is not released, 2. The scramble system according to claim 1, wherein it is impossible or difficult for the video recording / reproducing apparatus to detect the vertical synchronization from the video signal in which the second scramble is not released. 5. The key data is at least a set
The scramble system of claim 1 including a top box identification code and a descramble key. 6. The scramble system according to claim 1, wherein the key data is inserted in a vertical blanking period of a video signal. 7. The scramble system according to claim 1, further comprising a storage unit for storing the key data on the receiving side. 8. The video recording / reproducing apparatus records the date or viewing permission period of the program recorded together with the video signal, and when the program is reproduced from the video recording / reproducing apparatus, the program must be within the prescribed viewing permission period of the program. The scramble system according to claim 1, wherein the scramble is released. 9. The key data output from the first switching means to the video recording / reproducing apparatus is encrypted key data, and the second key extracting means decrypts the key data. The scramble system according to claim 1, wherein 10. The scramble system according to claim 1, wherein a viewing fee is charged according to a viewing period of the broadcasted program and / or a viewing period of playing the program recorded in the video recording / playback apparatus. 11. The scramble system according to claim 1, wherein the viewing fee is charged according to the number of times the program recorded in the video recording / reproducing apparatus is reproduced.