JPH08331508A - Recording reproducing system and its scrambler, and descrambler - Google Patents

Abstract

PURPOSE: To obtain higher security for the system than the case with scrambling all frames with same processing by making up of the system with a scrambler, a reproducing device and a descrambler decoding all frames in a 1st frame group in a reproduced signal by same processing under the control of 1st key data. CONSTITUTION: When a video signal is received by a scrambler 11, a divider 111 divides a video signal into a 1st frame group comprising I and P frames and a 2nd frame group comprising a B frame. Then a 1st ciphering device 112 receives the 1st frame group and 1st key data to cipher the 1st frame group under the control of the 1st key data. When the video signal is given to a descrambler 15, a divider 151 divides the video signal into the 1st frame group and the 2nd frame group. Then a 1st decoder 152 receives the 1st frame group and the 1st key data to decode the 1st frame group under the control of the 1st key data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing system and a scramble device for the same, which can be descrambled before recording and then scrambled for concealing the contents, and can be correctly descrambled even at high speed reproduction. It relates to a descrambling device.

[0002]

2. Description of the Related Art Prior to the explanation of the prior art, the Moving Picture Expert Group (Moving Picture Expert Group)
(MPEG): A joint working group of International Organization for Standardization ISO and International Electrotechnical Commission IEC) Standards will be explained. Regarding the MPEG standard, for example, ISO / IEC IS 111
72 (1993), ISO-IEC CD 13818 and other standards and drafts. FIG. 5 shows the structure of a frame according to the MPEG standard. A video signal based on the MPEG standard is basically composed of I frame, P frame and B frame as shown in FIG. Here, the I frame can independently restore the image regardless of other frames. Further, the P frame is a prediction frame, and an image can be restored by using it together with the I frame immediately before it, and the B frame is a bidirectional prediction frame, which is used together with the I frame or P frame immediately before and after it. It is possible to restore the image.

In a conventional recording / reproducing system for recording / reproducing a video signal composed of three types of frames of I / P / B conforming to the MPEG standard, when reproducing at high speed at the time of reproduction, it depends on the speed. Only the I-frames or I-frames and P-frames at intervals are reproduced.

In the conventional scrambler and descrambler, all frames are scrambled and descrambled by the same processing. Therefore, when applied to the conventional recording / reproducing system, high-speed reproduction is performed on the scrambled image,
Even if frames were thinned out, it was possible to properly descramble when descrambled.

Further, in the conventional recording system, when recording a scrambled video signal, a non-scrambled content introduction video is also recorded and the entire content is permitted to be viewed. Was needed. In the conventional recording system, in order to realize this function, an unscrambled content introduction image is created and recorded at the head portion of the recording medium or the like.

[0006]

However, in the above-mentioned configuration, all frames are scrambled by the same processing, so that there is a first problem that it is not possible to cope with higher security. It was

Further, in the above-mentioned structure, a recording area must be provided to record the unscrambled contents introduction image, and the second problem is that the original recording capacity for the image signal is reduced. Had.

In view of the above points, the present invention has as its first object to provide a recording / reproducing system having a higher level of safety than scrambling all frames by the same processing, and a scramble apparatus and a descramble apparatus thereof. To do.

Further, in view of the above points, a second object of the present invention is to provide a recording / reproducing system capable of recording an unscrambled content introduction image without reducing the original recording capacity for the image signal. And

[0010]

The first invention of the present invention is as follows:
Using a video signal composed of multiple frames as the input signal,
The frames are classified into a first frame group and a second frame group, the video signal, the first key data and the second key data are input, and all the frames of the first frame group in the input signal are the first key. It is repeatedly encrypted by the same process by controlling the data, and the second frame group in the input signal is secondly encrypted.
A scrambler that encrypts data by controlling key data,
A recording device that records the output of the scrambler as a recording signal, and a control signal that is separately input when the recording signal is reproduced, and is composed of all first frame groups and second frame groups in the recording signal. A reproduction signal that is output from the reproduction device, or a reproduction signal that outputs a reproduction signal that is composed of a part or all of the frames of the first frame group in the recording signal; The key data and the second key data are input, and all the frames of the first frame group in the reproduced signal are input to the first frame.
A recording / reproducing system comprising: a descrambler that decrypts the second frame group in the reproduction signal by the same process under the control of key data and decrypts the second frame group in the reproduction signal by controlling the second key data. .

According to a second aspect of the present invention, a video signal composed of a plurality of frames is used as an input signal, the frames are classified into a first frame group and a second frame group, and the video signal, first key data and With the second key data as an input, all the frames of the first frame group in the input signal are set to the first
The scrambler is characterized in that the second frame group in the input signal is encrypted by the same processing repeatedly under the control of the key data, and the second frame group in the input signal is encrypted under the control of the second key data.

According to a third aspect of the present invention, a video signal composed of a plurality of frames is used as an input signal, the frames are classified into a first frame group and a second frame group, and the video signal, first key data and With the second key data as an input, all the frames of the first frame group in the input signal are set to the first
The descrambling device is characterized in that it is repeatedly decrypted by the same process under the control of key data, and the second frame group in the input signal is decrypted under the control of the second key data.

According to a fourth aspect of the present invention, a video signal composed of a plurality of frames is used as an input signal, the frames are classified into a first frame group and a second frame group, and the input signal and key data are input. A scrambler for encrypting the second frame group in the input signal by controlling key data, a recorder for recording the output of the scrambler as a record signal, and a separate input for reproducing the record signal. By the control signal, a reproduction signal composed of all the first frame groups and second frame groups in the recording signal, or a part or all of the frames of the first frame group in the recording signal. A playback device that outputs a playback signal, a playback signal output from the playback device, and key data are input, and a second frame group in the playback signal is input to the key data. A recording and reproducing system, characterized in that composed of a descrambler for decoding the control.

A fifth aspect of the present invention uses a video signal composed of a plurality of frames as an input signal, classifies the frames into a first frame group and a second frame group, and inputs the input signal and key data. The scrambling device is characterized in that the second frame group in the input signal is encrypted by controlling key data.

According to a sixth aspect of the present invention, a video signal composed of a plurality of frames is used as an input signal, the frames are classified into a first frame group and a second frame group, and the input signal and key data are input. The descrambling device is characterized in that the second frame group in the input signal is decrypted by controlling key data.

[0016]

According to the recording / reproducing system of the first invention of the present invention, even if the reproducing apparatus reproduces only a part or all of the first frame group, the scrambler has the structure of the first frame group. All the frames are encrypted by the same process, and the descrambling device first
Since all the frames in the frame group are decoded by the same process, they can be correctly decoded. The process of reproducing a part or all of the first frame group in this reproducing device realizes high-speed reproduction. Therefore, even if the high-speed reproduction is performed after the processing by the scrambler, the descrambler can correctly descramble. Further, since the second frame group is subjected to arbitrary encryption processing, it is possible to have higher security than scrambling all the frames by the same processing.

The scrambling device of the second invention of the present invention can be used in the recording / reproducing system of the first invention due to the above-mentioned configuration. .

The descrambling apparatus of the third invention of the present invention can be used in the recording / reproducing system of the first invention with the above-mentioned configuration, and the video signal after being encrypted by the scrambling apparatus of the second invention. Can be restored correctly.

The recording / reproducing system according to the fourth aspect of the present invention has the above-mentioned configuration, and the scrambler scrambles the first frame group even when the reproducing apparatus reproduces some or all of the first frames. Since it does not perform, it is possible to audition the correct video regardless of the presence or absence of the descrambling device. Therefore, it is possible to notify the simple contents of the recording signal by the process of reproducing a part or all of the first frame in the reproducing device, and it is not necessary to add a recording area necessary for that purpose. Moreover, since the second frame group is encrypted by the control of the key data, the complete contents can be kept secret.

The scrambling device of the fifth invention of the present invention can be used in the recording / reproducing system of the first invention due to the above-mentioned configuration.

The descrambling apparatus of the sixth invention of the present invention can be used in the recording / reproducing system of the first invention with the above-mentioned configuration, and the video signal after being encrypted by the scrambling apparatus of the second invention. Can be restored correctly.

[0022]

2 is a block diagram of a scramble recording / reproducing system according to a first embodiment of the present invention. In FIG. 2, 11 is a scramble device, 12 is a recording device, 13 is a recording medium, 14 is a reproducing device, and 15 is a descrambling device. In the scramble device 11, 111 is a dividing device, 112 is a first encryption device, and 113. Is the second cryptographic device,
Reference numeral 114 denotes a synthesizing device, and in the descrambling device 15, 151 is a dividing device, 152 is a first decoding device, 15
3 is a second decoding device, and 154 is a synthesizing device. The input signal to the recording / reproducing system of this embodiment is a video signal compliant with the MPEG standard.

The operation of the scramble recording / reproducing system of this embodiment having the above-described structure will be described below.

The scrambler 11 inputs the input video signal and the first key data and the second key data in conformity with the MPEG standard, and agitates the input video signal by controlling the first and second key data. When the video signal is input to the scrambler 11, the dividing device 111 first divides the video signal into a first frame group consisting of I frames and P frames, and B
It is divided into a second frame group consisting of frames. Next, the first encryption device 112 inputs the first frame group and the first key data, and encrypts the first frame group by controlling the first key data. At this time, all the frames of the first frame group are repeatedly encrypted by the same process. In addition, the second encryption device 1
13 inputs the second frame group and the second key data,
The second frame group is encrypted by controlling the key data. In the encryption process at this time, there is no limitation such as repeating the same process, and any process may be used as long as it can be restored correctly. Next, the synthesizer 114 inputs the encrypted first frame group output from the first encryption device 112 and the encrypted second frame group output from the second encryption device 113, and divides these. The data is combined in the reverse conversion of the device 11 and output as data in a format compliant with the MPEG standard.

Next, the recording device 12 is the scrambler 1
The output of No. 1 is converted into data suitable for recording and then recorded on the recording medium 13. Next, the playback device 14 sets the recording medium 1
Play data from 3. At this time, when the high-speed reproduction is instructed by the separately inputted high-speed reproduction instruction signal, the reproducing device 14 reproduces all or part of the first frame group at intervals according to the instructed high-speed reproduction speed. To do.

Finally, the descrambling device 15 inputs the video signal outputted from the reproducing device 14 and the first key data and the second key data, and outputs from the reproducing device 14 under the control of the first and second key data. The image signals thus generated are mixed. When the video signal is input to the descrambling device 15, the dividing device 151 first divides the video signal into a first frame group and a second frame group. Next, the first decoding device 15
2 inputs the first frame group and the first key data, and decrypts the first frame group by controlling the first key data.
At this time, all the frames of the first frame group are repeatedly decoded by the same process. This is an inverse conversion of the first encryption device 112. Further, the second decryption device 153 inputs the second frame group and the second key data, and decrypts the second frame group by controlling the second key data. This is the reverse conversion of the second encryption device 113. Next, the synthesizing device 154 inputs the decrypted first frame group output from the first decrypting device 152 and the decrypted second frame group output from the second encrypting device 153, and outputs these. The data is combined in the reverse conversion of the division device 151, and output as data in a format compliant with the MPEG standard. Here, the dividing device 151 and the synthesizing device 154 are the same as the dividing device 1 in the scrambler 11.
11 and the composition device 114.

FIG. 1 is an explanatory view for explaining the outline of the processing of the scramble recording / reproducing system in the first embodiment of the present invention. As shown in the figure, the input video signal is divided into a first frame group consisting of I frames and P frames and a second frame group consisting of B frames, and the first encryption device 11
2 encrypts all the frames of the first frame group by the same process (process 1). In addition, the second encryption device 113
Processes each frame of the second frame group by an arbitrary process (process 2
~ Encrypt in process 11). Then, when the high-speed reproduction is instructed, the reproduction device 12 generates a reproduction signal composed of only the frames of the first frame group.

As described above, according to this embodiment, frames are thinned out at the time of high speed reproduction, and all or only some of the frames of the first frame group are reproduced. In the scrambler 11, all the frames of the first frame group are encrypted by the same process and are also decrypted by the same process at the time of decryption, so the frames of the first frame group can be scrambled and descrambled independently. Is. Therefore,
Correct descrambling is possible even when a scrambled video signal is reproduced at high speed. Also,
Since the second frame group is encrypted by an arbitrary method, it is possible to obtain higher security than scrambling all the frames of the video signal by the same processing.

In the scramble recording system according to the present embodiment shown in FIG. 1, I frame and P
Although the frame is the first frame group and the B frame is the second frame group, this is not a limitation. The same effect can be obtained by configuring the I frame as the first frame group and the P frame and the B frame as the second frame group.

The recording system of the first embodiment is shown in FIG.
Although the configuration is as shown in, it is not limited to this. The scrambler 11 and the descrambler 15 are
It is possible to use each independently, for example, between the scramble device 11 and the descramble device 15,
You may use for the transmission system connected by the communication apparatus connected by the wire or wireless. The scrambler 11 may transmit the signal after scrambling, and then the recording device 12 may record the signal. Even when the transmitted video signal is recorded, high speed reproduction is possible. The additional effect of being

FIG. 4 is a block diagram of a scramble recording / reproducing system according to the second embodiment of the present invention. In FIG. 4, 21 is a scramble device, 22 is a recording device, 23 is a recording medium, 24 is a reproducing device, and 25 is a descrambling device. In the scramble device 21, 211 is a dividing device, 212 is an encrypting device, and 213 is a combining device. In the descrambling device 25, 251 is a dividing device, 2
52 is a decoding device and 253 is a synthesizing device. The input signal to the recording / reproducing system of this embodiment is a video signal compliant with the MPEG standard.

The operation of the scramble recording / reproducing system of this embodiment having the above-mentioned structure will be described below.

The scrambler 21 inputs an input video signal and key data compliant with the MPEG standard, and agitates the input video signal by controlling the key data. When a video signal is input to the scrambler 21, first the divider 21
1 is a third frame group including an I-frame video signal,
It is divided into a fourth frame group consisting of P frames and B frames. Next, the encryption device 212 inputs the fourth frame group and the key data, and controls the key data to encrypt the fourth frame group. The encryption process at this time may be any process in which the reverse conversion exists. Next, the synthesizing device 213 inputs the third frame group output from the dividing device 211 and the encrypted fourth frame group output from the encrypting device 212, and performs these reverse conversions of the dividing device 211. The data is synthesized and output as data in a format compliant with the MPEG standard.

Next, the recording device 22 is the scramble device 2
The output of No. 1 is converted into data suitable for recording and then recorded on the recording medium 23. Next, the reproducing device 24 uses the recording medium 2
Play data from 3. At this time, when the content introduction is instructed by the separately introduced content introduction instruction signal, the reproducing device 24 reproduces all or some of the frames of the third frame group.

Finally, the descrambling device 25 inputs the video signal output from the reproducing device 24 and the key data, and mixes the video signal output from the reproducing device 24 by controlling the key data. When the video signal is input to the descrambling device 25, the dividing device 251 first divides the video signal into the third frame group and the fourth frame group. Next, the decryption device 252 inputs the fourth frame group and the key data, and decrypts the fourth frame group by controlling the key data. At this time, the reverse conversion of the encryption device 212 is performed. Next, the synthesizing device 253 inputs the third frame group output from the dividing device 251 and the decoded fourth frame group output from the decoding device 252, and performs the reverse conversion of the dividing device 251. Are combined, and the data is output in the form of data in conformity with the MPEG standard. Here, the dividing device 251 and the synthesizing device 253 have the same configurations as the dividing device 211 and the synthesizing device 213 in the scrambler 21.

FIG. 3 is an explanatory view for explaining the outline of the processing of the scramble recording / reproducing system in the first embodiment of the present invention. As shown in the figure, the input video signal is divided into a third frame group consisting of I frames and a fourth frame group consisting of P frames and B frames, the first frame group is not encrypted, and the encryption device 212 is Each frame of the fourth frame group is encrypted by arbitrary processing. And the playback device 2
When the content introduction is instructed, 2 generates a reproduction signal composed of only the frames of the third frame group.

As described above, according to this embodiment, when the content introduction is instructed, the frames are thinned and only a part or all of the third frame group is reproduced. Since all the frames of the third frame group are not encrypted in the scramble device 21, the reproduction signal when the content introduction is instructed is not disturbed regardless of the presence or absence of the descrambling device 25 and the key data. You can do it, and you can realize the function as a content introduction. The third frame group is the portion recorded as the original video signal. That is, no additional storage capacity is required for introducing the content. Furthermore, since the fourth frame group is encrypted, the parts other than those used for introducing the contents are
It is kept secret.

Therefore, in the recording / reproducing system for scrambling, the contents can be introduced without additional recording capacity.

In the second embodiment, the I frame is the third frame group, and the P frame and the B frame are the fourth frame.
Although it is configured to be a frame group, it is not limited to this. A part of the I frame may be set to the third frame group and the remaining frames may be set to the fourth frame group, and higher concealment can be obtained.

The recording system of the second embodiment is shown in FIG.
Although the configuration is as shown in, it is not limited to this. The scrambler 21 and the descrambler 25 are
It is possible to use each independently, for example, between the scramble device 21 and the descramble device 25,
You may use for the transmission system connected by the communication apparatus connected by the wire or wireless. Further, the scrambler 21 may transmit the signal after scrambled, and then the recording device 22 may record the signal. Even if the transmitted video signal is recorded, the introduction of contents can be supported. The additional effect of being

In the second embodiment, the content introduction control signal is input to the reproducing device 22, but the content introduction operation is performed by the control, but the present invention is not limited to this. The playback device 22 may have a configuration in which a high-speed playback control signal is input instead of the content introduction control signal, and the same operation is performed as high-speed playback according to the instruction. In this case, if the content introduction is desired, high-speed playback is performed. It suffices to perform the reproduction operation. According to this, an additional circuit is not required to introduce the contents.

In the first and second embodiments, MP
Although the signal conforming to the EG standard is used as the input video signal,
The present invention is not limited to this, and any signal can be used as long as it is a video signal composed of a plurality of frames.

[0043]

As described above, according to the first, second and third aspects of the present invention, even when special reproduction is performed after scrambling, it is possible to perform descramble correctly, and It is possible to provide a recording / reproducing system and its scrambler and descrambler which have higher security than that of scrambling the same frame by the same process, and its practical effect is great.

Further, the fourth, fifth and sixth aspects of the present invention
According to the invention of claim 1, anyone other than the person who has the device for descramble and the data can notify the simple contents of the recorded signal without adding the recording capacity necessary for that. It is possible to provide a recording / reproducing system and a scramble device and a descramble device thereof, and the practical effect thereof is great.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of processing of a recording system according to a first embodiment of the present invention.

FIG. 2 is a block diagram of the embodiment.

FIG. 3 is an explanatory diagram showing an outline of processing of a recording system according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of the embodiment.

FIG. 5 is an explanatory diagram showing an outline of processing of a conventional recording system.

[Explanation of symbols]

 11, 21 scramble device 12, 22 recording device 13, 23 recording medium 14, 24 reproducing device 15, 25 descrambling device 111, 151, 211, 251 dividing device 112 first cryptographic device 113 second cryptographic device 114, 154, 223 253 synthesizer 152 first decryption device 153 second decryption device 212 encryption device 252 decryption device

Claims (15)

[Claims] 1. An input signal is a video signal composed of a plurality of frames, and the frames are a first frame group and a second frame.
The video signal, the first key data and the second key data are input, and all the frames of the first frame group in the input signal are repeatedly encrypted by the same process under the control of the first key data. A scrambler for encrypting a second frame group in the input signal under control of second key data, a recorder for recording the output of the scrambler as a record signal, and a separate one for reproducing the record signal. By the input control signal, all the first frame groups and the second frames in the recording signal are
A reproduction device that outputs a reproduction signal that includes a frame group or a reproduction signal that includes a part or all of the frames of the first frame group in the recording signal; and a reproduction signal that is output from the reproduction device. , The first key data and the second key data are input, all the frames of the first frame group in the reproduction signal are decrypted by the same process under the control of the first key data, and the first key data and the second key data in the reproduction signal are decoded. A recording / reproducing system comprising a descrambling device for decrypting two frame groups by controlling the second key data. 2. A video signal composed of a plurality of frames is used as an input signal, and the frames are used as a first frame group and a second frame.
The video signal, the first key data and the second key data are input, and all the frames of the first frame group in the input signal are repeatedly encrypted by the same process under the control of the first key data. A scrambler which encrypts a second frame group in the input signal by controlling second key data. 3. A video signal composed of a plurality of frames is used as an input signal, and the frames are used as a first frame group and a second frame.
The video signal and the first key data and the second key data are input, and all the frames of the first frame group in the input signal are repeatedly decoded by the same process under the control of the first key data. A descrambling device for decoding the second frame group in the input signal by controlling the second key data. 4. The recording according to claim 1, wherein a video signal conforming to the MPEG standard is processed, the I frame and the P frame are a first frame group, and the B frame is a second frame group. Playback system. 5. A scrambler according to claim 2, wherein a video signal conforming to the MPEG standard is processed, the I frame and the P frame are a first frame group, and the B frame is a second frame group. apparatus. 6. A data frame according to claim 3, wherein a video signal conforming to the MPEG standard is processed, the I frame and the P frame are a first frame group, and the B frame is a second frame group. Scrambler. 7. The recording according to claim 1, wherein a video signal conforming to the MPEG standard is processed, an I frame is a first frame group, and a P frame and a B frame are a second frame group. Playback system. 8. A scrambler according to claim 2, wherein a video signal conforming to the MPEG standard is processed, an I frame is a first frame group, and a P frame and a B frame are a second frame group. apparatus. 9. A data processing apparatus according to claim 3, wherein a video signal conforming to the MPEG standard is processed, the I frame is a first frame group, and the P frame and the B frame are a second frame group. Scrambler. 10. A video signal composed of a plurality of frames is used as an input signal, the frames are classified into a first frame group and a second frame group, the input signal and key data are used as inputs, and the first signal in the input signal is used. A scramble device for encrypting two frame groups by controlling key data, a recording device for recording the output of the scramble device as a recording signal, and a recording signal by a control signal separately input when reproducing the recording signal. All first frame groups and second frames in the signal
A reproduction device that outputs a reproduction signal that includes a frame group or a reproduction signal that includes a part or all of the frames of the first frame group in the recording signal; and a reproduction signal that is output from the reproduction device. A recording / reproducing system comprising: a descrambler for inputting key data and decoding the second frame group in the reproduction signal by controlling the key data. 11. A video signal composed of a plurality of frames is used as an input signal, the frames are classified into a first frame group and a second frame group, the input signal and key data are used as inputs, and the first signal in the input signal is used. A scrambler characterized in that two frames are encrypted by controlling key data. 12. A video signal composed of a plurality of frames is used as an input signal, the frames are classified into a first frame group and a second frame group, the input signal and key data are used as inputs, and the first signal in the input signal is used. A descrambling device characterized by decoding two frame groups by controlling key data. 13. A video signal conforming to the MPEG standard is processed, a part or all of I frames are set as a first frame group, and frames other than the first frame group are set as a second frame group. The recording / reproducing system according to claim 10. 14. A video signal conforming to the MPEG standard is processed, a part or all of I frames are set as a first frame group, and frames other than the first frame group are set as a second frame group. The scrambler according to claim 11. 15. A video signal conforming to the MPEG standard is processed, a part or all of I frames are set as a first frame group, and frames other than the first frame group are set as a second frame group. The descrambling device according to claim 12.