JP2000092043A - Transmitter, receiver and system using them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit digital data relating to programs such as a compressed image in a form of a transport stream by transmitting key data through the use of a multi-value QAM digital modulation means or the like, an information storage medium or an FSK digital modulation means or the like without scrambling the data. SOLUTION: A data multiplex and contents scramble circuit 111 scrambles video/audio data 151 into scrambled video/audio data 157, which are fed to a time division multiplex circuit 102. Furthermore, 1st key data 152 and 2nd key data 153 that are used to cipher the video audio data 151 into the scrambled video audio data 157 are also fed to the time division multiplex circuit 102. The time division multiplex circuit 102 applies time division multiplex processing to the ciphered 1st key information, 2nd key information and the scrambled video audio data 157 as digital data of a transport stream form to obtain the scrambled video/audio key information multiplexed data 158, which are fed to a 64 QAM modulation circuit 103.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitter and a receiver for television broadcasting and a system using the same. The present invention relates to a conditional access system that specifies and permits reception.

[0002]

2. Description of the Related Art Conventionally, as for a conditional access system in television broadcasting using a CATV transmission line called a cable television, a cable television technology committee, published by Corona, edited by the Cable Machinery Engineering Committee of the Electronic Machinery Manufacturers Association. Getting Started ”. According to the description, a method called a one-way addressable system is described.
In this method, the descrambling function in the home terminal on the receiving side is controlled by the FSK modulation downlink from the transmitting side. Although there is no detailed description of the scramble system,
In the following circumstances, the method has changed while progressing.
First, as a simple conditional access method, there was a popular name channel skip method that restricts the selection of a CATV receiver by downlink control information transmitted by FSK modulation or the like in a band other than the channel transmitting the video signal. . According to the channel skip method, a CATV receiver skips receivable channels according to downlink control information so that a receiver cannot receive a channel for which the receiver has not subscribed. When was sold to general users, the restrictions on song selection were removed, and it was possible to receive skipped channels, so the function of the above-mentioned method became meaningless.
As another conditional access system, there is a scramble system of synchronous compression. In this method, the level of the horizontal synchronization signal of NTSC video is transmitted at a reduced level, so that it cannot be played back on a TV receiver that supports the CATV channel. When receiving a contracted channel, the level can be reproduced by extending the period of the horizontal synchronizing signal, which has been compressed and reduced to a normal level. The scramble system of the synchronous compression is generally used as a conditional access system for analog television broadcasting for transmitting NTSC video, but does not describe a conditional access system for digital cable television broadcasting.

[0003] With the recent development of digital transmission technology and the like, NTSC video transmission channels, which are analog signals, are transmitted.
A number of digitized images are being transmitted on one channel. Regarding the digital transmission of this cable television, see the Telecommunications Society of Japan Technical Report (vol.19, No.42) published on September 21, 1995, pages 19 to 24, John Broadcasting Transmission Experiment ". According to this report, Empeg 2 (MP
EG2) is a data stream in a format called a transport stream in which digital data such as images compressed by digital image compression technology called multiplexed data is processed. The signal is modulated by a digital modulation technique called "modulation" and transmitted on a CATV transmission line. This report does not describe the conditional access system.

[0004] On the other hand, there is a digital satellite television broadcast as a method for distributing multi-channel digitized video, which is described in Nikkei Electronics 1996.
This is achieved by a combination of digital image compression technology and digital transmission technology, as described in the September 2, 1998 issue on page 149, "Japan's First Digital Satellite Broadcasting to Realize Nearly 70 Multi-Channels." According to this paper, a conditional access system that specifies a recipient and permits reception is realized by a scrambling system unique to Japan and descrambling by an IC card. As described above, the satellite television broadcasting is a system using an IC card or a telephone line without an upstream line for transmitting information from each home to a transmitting side for broadcasting via a satellite. In this paper, there is no description for adapting the scramble system and the conditional access system for descrambling by the IC card to other transmission systems such as digital cable television broadcasting.

A conditional access system for digital television broadcasting of cable television is described in Japan.
The standardization method was examined by the Standardization and Standardization Committee of the CATV Technology Association, and in April 1997, JCTEA STD 001-1.0 was issued. According to this, in a manner similar to the above satellite television broadcast, a transport stream such as video and audio is scrambled by a first key data on a transmission side, and then the first key data is encrypted by a second key data. The encrypted and encrypted first key data is time-division multiplexed with a transport stream such as video and audio scrambled by the first key data. Further, the second key data is encrypted by the third key data, the encrypted second key data is the video and audio scrambled by the first key data and the encrypted first key data It is time-division multiplexed with transport stream data such as key data and transmitted. This output data stream is 64QAM
The signal is modulated by a modulating means such as digital modulation, and a plurality of modulated waves are frequency-multiplexed by a signal combining means and transmitted to a transmission path. Here, a method of storing the third key data in an IC card is considered.

On the other hand, the receiving side demodulates digital modulated waves such as multi-level QAMs such as 64-values transmitted in a frequency multiplexed manner by demodulation means, performs error correction, and multiplexes the waves by an MPEG separation circuit. Separate port streams.
The encrypted second key data included in the separated transport stream is decrypted using the third key data obtained in advance from the IC card, and the encrypted second key data included in the separated transport stream is decrypted. The decrypted first key data is decrypted using the decrypted second key data. By using the decrypted first key data, the scrambled video and audio can be decrypted. The decoded video and audio transport streams are separated by an MPEG separation circuit and are reproduced by respective decoders.

[0007]

Conventionally, there is no detailed definition of a conditional access system for digital cable television broadcasting using a CATV transmission line, and in a channel skip system like a conventional analog receiver, a digital cable television system is not used. When a television receiver compatible with John Broadcasting is sold to general users, the function of conditional access is lost. In digital cable television broadcasting, the signal to be transmitted is not an NTSC video and there is no horizontal synchronization signal. Under these circumstances, it is conceivable to adopt a conditional access method for digital satellite television broadcasting that transmits the same type of transport stream. Not been. Satellite television broadcasting is broadcast to viewers nationwide, whereas cable television broadcasting is broadcast to viewers in a limited area with a cable. As a conditional access system for cable television broadcasting, a system having a simple configuration and considerable security is desired.

SUMMARY OF THE INVENTION An object of the present invention is to provide a transmission apparatus and a reception apparatus of a conditional access system for digital cable television broadcasting in which digital data relating to a program such as a compressed image is transmitted in a format called a transport stream, and a system using the same. Is to provide.

[0009]

In order to solve the above-mentioned problems, the present invention provides first key data and second key data for scrambling a part of digital data in the mpeg transport stream format. Content scrambling means for performing a scramble operation using the operation results of the two types of key data is provided, and both the first key data and the second key data are time-division multiplexed in the MPPEG transport stream format. The first modulation means for applying digital modulation such as multi-level QAM such as 64 values or the second modulation means for applying digital modulation such as FSK or information storage means such as a semiconductor memory or IC card capable of storing data is used. Transmitting means, and a first demodulating means for performing digital demodulation such as multi-level QAM such as 64 values transmitted in a frequency multiplexed manner, A time-division multiplexing / demultiplexing means for separating content-scrambled data from time-division multiplexed data in the MPPEG transport stream format which is the output of the demodulation means; The first key data or the second key data 2 obtained by the information storage means or the second demodulation means for performing digital demodulation such as FSK.
And a descrambling unit for obtaining digital data in a transport stream format from the content-scrambled data obtained by the first demodulation unit based on the operation result of the type of key data.

That is, on the transmitting side, the digital data in the transport stream format is scrambled and transmitted according to the operation result of the two types of key data of the first key data and the second key data, and the key data is transmitted by 64 bits. The data is transmitted without scrambling using digital modulation means such as multi-valued QAM such as a value, or an information storage medium or digital modulation means such as FSK.

On the receiving side, the key data is converted to a multi-value QA
While receiving using digital demodulation means such as M or an information storage medium or digital demodulation means such as FSK, the descrambling of the content scramble is performed based on the operation result of the two types of key data of the first key data and the second key data. To receive digital data in a transport stream format.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing a configuration of a conditional access transmission apparatus for a cable television and an arrangement of the reception apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 100 denotes a transmission-side encryption modulator, 200 denotes a transmission-side video signal source device, 300 denotes a transmission-side key management device, 400 denotes a CATV transmission path,
500 is a receiving terminal device, 600 is a video / audio output device, 101 is an encryption device, 102 is a time-division multiplexing circuit, 103 is 64QAM (Quadratu
reamplitude modulation), 104 is a signal synthesis circuit, 111 is a data multiplexing and content scramble circuit, 151 is video and audio data, 152 is first key data, 153 is second key data, and 157 is scrambled video and audio Data, 15
8 is scrambled video / audio key information multiplexed data, 159 is 64QA
M digital modulated wave signal, 501 is frequency multiplexed signal separation circuit, 502 is control microcomputer, 503 is 64QAM demodulation circuit, 504 is error correction circuit, 505 is key data separation circuit, 508 is content descramble circuit, 509 is MPEG Demultiplexing circuit, 510
MPEG video decoder, 511 is NTSC (National Television
System Committee) Video encoder, 512 is audio decoder, 551 is control signal, 552 is 64QAM modulated wave signal, 5
53 is 64QAM demodulated digital data, 555 is error-corrected digital data, 559 is second key data, 560 is first key data,
561 is descrambling digital data, 562 is compressed video data, 564 is video data, 563 is compressed audio data,
565 is an NTSC video signal, and 566 is an analog audio signal.

A cable television transmission device having a conditional access system is composed of a transmission side encryption / modulation device 100, a transmission side video signal source device 200 and a transmission side key etc. management device 300. The video / audio data 151 including video and audio data from the MFP is digital data in an MPEG2 transport stream format or a format that can be converted into a transport stream, and is input to the data multiplexing and content scrambling circuit 111 of the encryption device 101. Then, the first key data 152 and the second key data 153 from the transmission-side key etc. management device 300 are used as scrambled video / audio data 157 obtained by scrambling video / audio data of transport stream format digital data. It is applied to the multiplexing circuit 102. First key data 152 obtained by encrypting video / audio data 151 into scrambled video / audio data 157
The second key data 153 is also applied to the time division multiplexing circuit 102. In the time-division multiplexing circuit 102, the first key data 152, the second key data 153, and the scrambled video / audio data 157 are time-division multiplexed as digital data in the form of a transport stream. 158 is applied to the 64QAM modulation circuit 103. The 64QAM modulation circuit 103 adds an error correction code to the scrambled video / audio key information multiplexed data 158, performs interleaving processing, energy spreading processing, etc., converts it into a 64QAM digital modulated wave signal 159, and passes through the signal synthesis circuit 104 The signal is frequency-multiplexed with another 64QAM digital modulated wave signal, analog modulated wave signal, or the like, and output to the CATV transmission line 400.

On the other hand, a receiving device for a cable television having the conditional access system includes a receiving terminal device 500. In the receiving terminal device 500, the frequency multiplexed and transmitted 64Q
The AM digital modulated wave signal is received from the CATV transmission path 400, and the 64QAM modulated wave signal 552 selected by the frequency multiplexing signal separation circuit 501 in accordance with the control signal 551 from the control microcomputer 502 is 6
The signal is input to the 4QAM demodulation circuit 503. 64Q with 64QAM demodulation circuit 503
The AM modulated wave signal 552 is demodulated into 64QAM demodulated digital data 553, and an error in the data generated on the transmission line is corrected by an error correction circuit 504. Input to 505. Note that the error correction circuit 504 also decodes data that has been subjected to interleave processing and energy diffusion processing. In the key data separation circuit 505, the first key data
560 and second key data 559 are obtained. The content descrambling circuit 508 decodes the error-corrected digital data 555 encrypted with the obtained first key data 560 and the obtained second key data 559, and outputs the descrambled digital data in the MPEG2 transport stream format. data
Returned to 561, compressed video data 56
2 and the compressed audio data 563 are input to the MPEG video decoder 510 and the audio decoder 512. The compressed video data 562 is converted to video data 564 by the MPEG video decoder 510, and is converted by the NTSC video encoder 511.
Converted to NTSC video signal 565. The compressed audio data 563 is converted into an analog audio signal 566 by the audio decoder 512. The NTSC video signal 565 and the analog audio signal 566 are input to the video / audio output unit 600, and information such as video and audio displayed on the video / audio output unit 600 can be provided to the viewer.

As described above, in the present embodiment, when the viewer watches the contracted channel, the first key data 560 and the second key data 559 are obtained, so that the content scrambled error Digital data after correction
555 can be decoded and converted back to the descrambled digital data 561 in the MPEG2 transport stream format, and information such as video and audio of the contracted channel can be obtained. Even if an unsubscribed viewer tries to view an unsubscribed channel, the first key data 560 and the second key data 559 cannot be obtained, so the digital data 555 after error correction with the content scrambled cannot be decrypted. , Can not get information. That is, a conditional access system of digital cable television broadcasting is achieved.

FIG. 2 is a block diagram showing a configuration of a transmission apparatus of a conditional access system for a cable television according to another embodiment of the present invention and a configuration of the reception apparatus. In FIG. 2, 201 is
MPEG-TS time-division multiplexing circuit, 202 is a content scramble circuit, 203 is an MPEG-TS multiplexing / demultiplexing circuit, 251 and 252 are video and audio data including video and audio data, 253 is MPEG-TS multiplexed data, and 254 is The demodulated first key data, 255 is demodulated second key data, and the same reference numerals shown in FIG. 1 denote the same units or data as those described with reference to FIG. Show.

FIG. 2 is a block diagram showing the transmission-side encryption modulator shown in FIG.
100 data multiplexing and content scrambling circuits 111
And the time-division multiplexing circuit 102 are replaced with the MPEG-TS time-division multiplexing circuit 201 and the content scramble circuit 202, and the key data separation circuit 505 and the MPEG multiplexing / demultiplexing circuit 509 are replaced with the MPEG-TS multiplexing / demultiplexing circuit 203.
It is configured in place of.

Video and audio data 25 including a plurality of video and audio data output from the transmission side video signal source device 200
1, 252 and the first output from the transmission side key etc. management device 300.
The key data 152 and the second key data 153 are added to the MPEG-TS time-division multiplexing circuit 201 and time-division-multiplexed to MPEG-TS multiplexed data 253. Thereafter, in the content scramble circuit 202, the scrambled video / audio key obtained by scrambling the video / audio data of the transport stream format digital data with the first key data 152 and the second key data 153 output from the transmission side key etc. management device 300. The information multiplex data 158 is supplied to the 64QAM modulation circuit 103.

On the other hand, in the receiving side terminal device 500, the MPE
Using the first key data 254 and the second key data 255 obtained in the G-TS demultiplexing circuit 203, the content descrambled in the content descramble circuit 508 is descrambled and descrambled in the MPEG2 transport stream format. Digital data 561 is obtained. The MPEG-TS demultiplexing circuit 203 separates the descrambled digital data 561 into compressed video data 562 and compressed audio data 563.

The descrambled digital data 561 in the MPEG2 transport stream format, which is the output signal of the content descramble circuit 508, is converted from the MPEG-
The first key data 254 and the second key data 255 can be obtained by the TS multiplexing / demultiplexing circuit 203 because packets of MPEG video data and MPEG audio data are scrambled, and data of key information is transmitted without being scrambled. Because it is. The packet structure is shown in FIG. 5 and FIG. As shown in FIG. 5, the MPEG2 transport stream is MPE
A packet 5002 of G video data and MPEG audio data and a packet header 5001 attached thereto are provided. As shown in FIG. 6, the packet header 5001 has a transport scramble control 6006. According to the transport scramble control 6006, it is possible to set a flag for controlling whether each packet of the transportable MPEG2 transport stream is scrambled or not, so that the packet 5002 of the MPEG video data and the MPEG audio data can be set. Is scrambled, and the key information data can be transmitted without being scrambled.

As described above, in the present embodiment, the key data separation circuit 505 and the MPEG multiplex separation circuit 509 of FIG. 1 are shared in addition to being able to fulfill the conditional access system of digital cable television broadcasting. MPEG-TS demultiplexing circuit 203
And there is also an advantage that the circuit can be simplified.

In the following embodiments of the present invention, FIG.
The description based on the configuration shown in FIG. 2 and the description based on the configuration shown in FIG. 1 will be omitted, but the embodiment of the present invention can also be implemented based on the configuration shown in FIG.

FIG. 3 is a block diagram showing the structure of scrambling in the embodiment of the present invention. In FIG. 3, 300
0 is scramble, 3001 is input data switching, 3002 is output data switching, 3003 is CBC mode configuration, 3004 is O
FB mode configuration, 3005 is MULTI2 encryption device, 3006 is EO
R, 3007 is a register, 3051 is video and audio data, 3052 is scrambled video and audio data, 3053 is first key data, 305
4 is the second key data, 3055 is the MULTI2 encryption device input signal,
3056 is a MULTI2 encryption device output signal.

In FIG. 3, the structure of scramble 3000, video / audio data 3051, scrambled video / audio data 3052,
The first key data 3053 and the second key data 3054 correspond to the data multiplexing and content scrambling circuit 111 shown in FIG.
, The video / audio data 151, the scrambled video / audio data 157, the first key data 152, and the second key data 153. These are the content scramble circuit 202 shown in FIG. 2, the MPEG-TS multiplexed data 253,
It corresponds to scrambled video / audio key information multiplexed data 158 obtained by scrambling video / audio data of digital data in a transport stream format, first key data 152, and second key data 153.

Video / audio data 3051 is input data switching
According to 3001, if the block length is 8 bytes, it is processed in the configuration 3003 of the CBC mode, and if the block length is not 8 bytes, it is processed in the configuration 3004 of the OFB mode and the output data switching 3002, and the scrambled video / audio data 3052 Is output as In the configuration 3003 in the CBC mode, the video / audio data 3051 is subjected to exclusive OR processing (exclusive OR) with the signal data from the register 3007 in the EOR 3006, and the MULTI2
It is applied to the MULTI2 encryption device 3005 as an encryption device input signal 3055. Then, the MULTI2 encryption device input signal 3055
Is MULTI2 encrypted by the first key data 3053 and the second key data 3054 which are separately added to the MULTI2 encryption device 3005, is added to the register 3007 as the MULTI2 encryption device output signal 3056, and the output data switching 30
02 and output as scrambled video / audio data 3052. In the OFB mode configuration 3004, the signal data of the register 3007 is used as the MULTI2 encryption device input signal 3055 as the MULTI2 encryption device input signal 3055.
Added to encryption device 3005. The MULTI2 encryption device input signal 3055 is composed of first key data 3053 and second key data 3054 separately added to the MULTI2 encryption device 3005.
The MULTI2 encryption processing is performed and the signal data of the register 3007 is updated as the MULTI2 encryption device output signal 3056 and added to the EOR 3006. The exclusive OR (exclusive OR) processing with the video / audio data 3051 is performed to switch the output data. 3052 scrambled video / audio data via 3002
Is output as

FIG. 4 is a block diagram showing a configuration of the MULTI2 encryption device 3005 according to the embodiment of the present invention. In FIG. 4, 4000 is a MULTI2 encryption device, 4001 is a key processing unit, 4002
Is the encryption unit, 4051 is the MULTI2 encryption device input signal, 4052 is
MULTI2 encryption device output signal, 4053 is first key data, 405
Reference numeral 4 denotes second key data, and reference numeral 4055 denotes key processed key data.

The MULTI2 encryption device 4000 uses the MUL shown in FIG.
This shows the details of the TI2 encryption device 3005,
The LTI2 encryption device input signal 4051 and the MULTI2 encryption device output signal 4052 correspond to the MULTI2 encryption device input signal 3055 and the MULTI2 encryption device output signal 3056 in FIG. Also,
First key data 4053 and second key data 405 in FIG.
4 is the first key data 3053 and the second key data 3054 in FIG.
Alternatively, the first key data 152 and the second key data 152 in FIG. 1 and FIG.
Key data 153.

First key data 4053 and second key data 40
Numeral 54 denotes key data 4055 that has been processed by the key processing unit 4001 and key-processed, and the key data 40 key processed by the encryption unit 4002.
The MULTI2 encryption device input signal 4051 is encrypted (scrambled) by 55 to obtain a MULTI2 encryption device output signal 4052.
Is obtained.

The encryption algorithm of the MULTI2 encryption device is publicly available and registered in ISO-9979 / 0009.

FIG. 5 is an MPE for explaining the embodiment of the present invention.
FIG. 3 is a conceptual diagram illustrating a signal configuration of a G2 transport stream format. In FIG. 5, 5001 is a packet header, 5002
Indicates a packet of MPEG video data or MPEG audio data, and 5003 indicates an error correction code. The data of the descrambled digital data 561 returned to the MPEG2 transport stream format of the receiving terminal device 500 is a packet header 50 of 4 bytes.
16 bytes of Reed-Solomon data into 188 bytes of MPEG2 transport stream data consisting of 01 and 184 bytes of MPEG video data and MPEG audio data packets 5002
An error correction code 5003 called (204,188) is added.

FIG. 6 shows an MPE for explaining the embodiment of the present invention.
FIG. 3 is a conceptual diagram showing a signal configuration of a packet header in a G2 transport stream format. In FIG. 6, 6001 is a synchronization byte, 6002 is a transport error indicator, 60
03 indicates a payload unit start indicator, 6004 indicates a transport priority, 6005 indicates a packet identifier, 6006 indicates a transport scramble control, 6007 indicates an adaptation field control, and 6008 indicates a continuity index. FIG. 6 shows details of the 4-byte packet header 5001 shown in FIG. 5, and a packet identifier 6005 indicating what kind of data packet the MPEG video data or MPEG audio data packet 5002 is.
And a transport scramble control 6006 indicating whether or not the data packet has been scrambled. By this transport scramble control 6006, the MPEG video data shown in FIG.
It can be seen that the packet of the MPEG audio data is scrambled, and the data of the key information is transmitted without being scrambled.

FIG. 7 is a block diagram showing a configuration of a transmission apparatus of a conditional access system for a cable television according to another embodiment of the present invention and a configuration of the reception apparatus. In FIG. 7, 701 is
FSK (Frequency Shift Keying) modulation circuit, 702 is an FSK demodulation circuit, 751 is an FSK modulated wave signal, 752 is an FSK modulated wave signal subjected to frequency multiplex separation, 753 is FSK demodulated first key data, 754 is The second key data subjected to FSK demodulation, and those having the same codes as those shown in FIG. 1 or FIG. 2 indicate the same means or data as described with reference to FIG. 1 or FIG.

In this embodiment, the transmitting-side encrypted modulation device 10
The first key data 152 and the second key data 153 of 0 are directly added to the FSK modulation circuit 701 and digitally modulated.
The FSK modulated wave signal 751 is applied to the signal synthesis circuit 104 as 6
Frequency multiplexed with 4QAM digital modulated wave signal 159 etc. and C
Output to ATV transmission path 400.

On the other hand, in the receiving-side terminal device 500, the FSK modulated wave signal which has been frequency-multiplexed and transmitted is frequency-multiplexed and separated by the frequency-multiplexed signal separation circuit 501, and the frequency-multiplexed separated FSK modulated wave signal 752 is obtained. The first key data 753 and the second key data 754 demodulated by the FSK demodulation circuit 702 and directly obtained from the FSK demodulated data are added to the content descrambling circuit 508, and the error-corrected digital Data 555 is decoded, and descrambled digital data 561 in the MPEG2 transport stream format is used.
Is returned to. In the present embodiment, the first key data 152 and the second key data 153 can perform the conditional access method of the digital cable television broadcasting, Therefore, it is necessary to simultaneously decode the 64QAM digital modulated wave signal and the downlink control line modulated wave signal.

FIG. 8 is a CAT for explaining the embodiment of the present invention.
FIG. 3 is a conceptual diagram illustrating a frequency arrangement of a V transmission path. In FIG. 8, reference numeral 8001 denotes a whole downlink signal band, 8002 denotes a 64QAM digital modulated wave signal, and 8003 denotes a downlink control line modulated wave signal such as a modulated wave signal. The figure shows an example of the transmission signal form of the CATV transmission line 400.In the entire downlink signal band 8001, a 64QAM digital modulated wave signal 8002 for transmitting scrambled video / audio data, the first key data 152 and the second Downlink control line modulated wave signal 8003 for transmitting key data 153 etc.
Video and audio data that has not been scrambled
A plurality of modulated wave signals such as a 64QAM digital modulated wave signal and a modulated wave transmitting analog video and audio are frequency-multiplexed.

FIG. 9 is a block diagram showing a configuration of a transmitting apparatus of a conditional access system for a cable television according to another embodiment of the present invention and a configuration of the receiving apparatus. 9, reference numeral 901 denotes an information storage medium such as an IC card; 900, a delivery means such as mailing; 951, first key data obtained from the information storage medium;
Reference numeral 2 denotes second key data obtained from the information storage medium, and the same reference numerals as those shown in FIG. 1 or FIG.
Alternatively, the same means as the means or data described with reference to FIG. 2 is shown.

In this embodiment, the transmitting-side encrypted modulation device 10
0 of the first key data 152 and the second key data 153
It is stored in an information storage medium 901 such as a card. An information storage medium such as an IC card is distributed by a delivery means 900 such as mailing to a cable television receiving apparatus having a conditional access system.

On the other hand, in the receiving terminal device 500, I
The first key data 951 and the second key data 952 obtained from the information storage medium 901 such as a C card are added to the content descrambling circuit 508, whereby the encrypted error-corrected digital data 555 is decrypted. The MPEG2 transport stream format descrambled digital data 56
Returned to 1. Regarding the input and output of data using the IC card, for example, data input is performed by an IC card issuing device using a personal computer or the like under the control of the transmission-side key management device 300, and data output is performed by the receiving terminal. Device 50
What is necessary is just to perform by the socket under management of 0.

In this embodiment, in addition to being able to fulfill the conditional access system of digital cable television broadcasting, the key data is exchanged to store the key data in an information storage medium 901 such as an IC card. There is an advantage that data can be updated.

In this embodiment, a method of transmitting key data by delivering an IC card storing key data has been described. In addition, an IC memory storing key data in advance is received. Built in the device,
A method of transmitting key data inside the receiving device, a method of transmitting key data from a remote control by incorporating an IC memory in which key data is stored in advance in a remote controller corresponding to the receiving device, and a method of transmitting key data via a network server And a method of transmitting key data by a modem via a telephone line.

FIG. 10 is a block diagram showing a configuration of a transmission apparatus of a conditional access system for a cable television according to another embodiment of the present invention and a configuration of the reception apparatus. In FIG.
The same reference numerals as those shown in FIG. 1, FIG. 2 or FIG.
The same means or data as those described with reference to FIG. 2 or FIG. 9 are shown.

In the present embodiment, the transmitting-side encrypted modulation device 10
The first key data 152 of 0 is directly added to the MPEG-TS time-division multiplexing circuit 201 as it is, and is scrambled video / audio key information multiplexed data 158 which is time-division multiplexed with a plurality of scrambled video signals and encrypted. And 64Q
It is transmitted as an AM digital modulated wave signal 159. No. 2
Key data 153 is stored in an information storage medium 901 such as an IC card.

On the other hand, in the receiving terminal device 500, the MPE
The first key data 254 obtained by the G-TS demultiplexing circuit 203 and I
The second key data 952 obtained from the information storage medium 901 such as a C card is added to the content descrambling circuit 508,
Error-corrected digital data encrypted by this
555 is decoded and returned to the descrambled digital data 561 in the MPEG2 transport stream format. In the present embodiment, in addition to being able to fulfill the conditional access system of digital cable television broadcasting, the first key data 1
Since the 52 or the second key data 153 is transmitted by two types of transmission means using an information storage medium such as a 64QAM digital modulated wave signal and an IC card, it is difficult to analyze the key data, and the advantage of being strong against eavesdropping. There is.

FIG. 11 is a block diagram showing a configuration of a transmission apparatus of a conditional access system for a cable television according to another embodiment of the present invention and a configuration of the reception apparatus. In FIG.
The same reference numerals as those shown in FIG. 1, FIG. 2 or FIG.
The same means or data as described with reference to FIG. 2 or FIG. 7 is shown.

In the present embodiment, the transmitting-side encrypted modulation device 10
The first key data 152 of 0 is directly applied to the MPEG-TS time-division multiplexing circuit 201 as it is, and is scrambled video / audio key information multiplexed data 158 which is time-division multiplexed with a plurality of scrambled video signals and encrypted. And transmitted as a 64QAM digital modulated wave signal 159. The second key data 153 is directly applied to the FSK modulation circuit 701 as it is, digitally modulated, and transmitted as an FSK modulated wave signal 751.

On the other hand, in the receiving side terminal device 500, the MPE
First key data 254 and FSK obtained by G-TS demultiplexing circuit 203
The second key data 754 directly obtained from the data demodulated by the demodulation circuit 702 is added to the content descrambling circuit 508, whereby the encrypted error-corrected digital data 555 is decrypted, and the MPEG2 transport stream is decoded. The format is returned to the descrambled digital data 561.
In the present embodiment, in addition to being able to fulfill the conditional access system of the digital cable television broadcasting, the first key data 152 or the second key data 153 is converted to a 64QAM digital modulated wave signal and an FSK modulated wave signal. Since transmission is performed using the two types of transmission means used, eavesdropping requires simultaneous decoding of 64QAM digital modulated wave signals and downlink control line modulated wave signals such as FSK modulated wave signals. is there.

FIG. 12 is a block diagram showing a configuration of a transmission apparatus of a conditional access system for a cable television according to another embodiment of the present invention and a configuration of the reception apparatus. In FIG.
The same reference numerals as those shown in FIG. 1, FIG. 2, FIG. 7, or FIG.
The same means or data as those described with reference to FIG. 1, FIG. 2, FIG. 7, or FIG.

In this embodiment, the transmitting-side encrypted modulation device 10
The first key data 152 of 0 is directly applied to the FSK modulation circuit 701 as it is, digitally modulated, and transmitted as an FSK modulated wave signal 751. The second key data 153 is stored in an information storage medium 901 such as an IC card.

On the other hand, in the receiving terminal device 500, FS
The first directly obtained from the data demodulated by the K demodulation circuit 702
Key data 753 and the second key data 952 obtained from the information storage medium 901 such as an IC card are added to the content descrambling circuit 508, and the encrypted error-corrected digital data 555 is decrypted, and the MPEG2 This is returned to the descrambled digital data 561 in the transport stream format. In the present embodiment, in addition to being able to fulfill the conditional access system of digital cable television broadcasting, the first
Key data 152 and the second key data 153 are transmitted by the FSK modulated wave signal and two types of transmission means using an information storage medium such as an IC card, so that eavesdropping such as the FSK modulated wave signal is performed. It is necessary to simultaneously decode the modulated signal of the control line and the information storage medium such as an IC card, which is advantageous in that it is difficult to eavesdrop.

The first key data 152 and the second key data 1 are not limited to the embodiment shown in FIG. 10, FIG. 11 or FIG.
One of the key data 53 is transmitted by a transmission means using either a 64QAM digital modulated wave signal, an IC card or an information storage medium of an IC memory in a receiving device, or a downlink control line modulated wave signal such as a FSK digital modulated wave signal. It goes without saying that the same operation can be obtained even if the other key data is transmitted by any other transmission means, and the object of the present invention can be achieved.

[0051]

According to the present invention, data scrambled by a plurality of key data is transmitted by a 64QAM digital modulated wave signal, and a plurality of key data for descrambling are transmitted by a 64QAM digital modulated wave signal or an IC card. Or from an information storage medium such as an IC memory or an FSK digital modulated wave signal, so that when a viewer looks at a contracted channel, the scrambled data can be descrambled and the contracted channel can be obtained. Information such as video and audio can be obtained. But if viewers try to watch a channel that they haven't subscribed to,
Since there is no IC card, there is no necessary data in the IC memory, or there is no means for obtaining the key data, the key data cannot be obtained, so that the scrambled data cannot be descrambled. , Can not get information. In other words, it is possible to use a conditional access system for digital cable television broadcasting with a simple configuration and considerable security.

As described above, the present invention is an extremely effective technique capable of providing a conditional access system for digital cable television broadcasting.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a conditional access system transmission apparatus for a cable television according to an embodiment of the present invention and a configuration of the reception apparatus.

FIG. 2 is a block diagram showing a configuration of a transmission apparatus of a conditional access system for a cable television according to another embodiment of the present invention and a configuration of the reception apparatus.

FIG. 3 is a block diagram showing a configuration of scrambling in the embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a MULTI2 encryption device according to an embodiment of the present invention.

FIG. 5 is a conceptual diagram showing a signal configuration of an MPEG2 transport stream format for describing an embodiment of the present invention.

FIG. 6 is a conceptual diagram showing a signal configuration of a packet header in an MPEG2 transport stream format for describing an embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a transmission apparatus of a conditional access system for a cable television according to another embodiment of the present invention and a configuration of the reception apparatus.

FIG. 8 is a conceptual diagram showing a frequency arrangement of a CATV transmission line for describing an embodiment of the present invention.

FIG. 9 is a block diagram illustrating a configuration of a transmission apparatus using a conditional access system for a cable television according to another embodiment of the present invention and a configuration of the reception apparatus.

FIG. 10 is a block diagram showing a configuration of a transmission apparatus of a conditional access system for a cable television according to another embodiment of the present invention and a configuration of the reception apparatus.

FIG. 11 is a block diagram illustrating a configuration of a transmission apparatus of a conditional access system for a cable television according to another embodiment of the present invention and a configuration of the reception apparatus.

FIG. 12 is a block diagram illustrating a configuration of a transmission apparatus using a conditional access system of a cable television according to another embodiment of the present invention and a configuration of the reception apparatus.

[Explanation of symbols]

 100: transmitting-side encryption modulator 200: transmitting-side video signal source device 300: transmitting-side key etc. management device 400: CATV transmission line 500: receiving-side terminal device 600: video / audio output device 101: encryption device 102: time division Multiplexing circuit 111 Data multiplexing and content scrambling circuit 201 MPEG-TS time-division multiplexing circuit 202 Content scrambling circuit 203 MPEG-TS demultiplexing circuit 503 64QAM demodulation circuit 505 Key data separating circuit 508 Content descramble circuit 509: MPEG demultiplexing circuit 901: Information storage medium

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04N 7/081 H04N 7/13 Z 7/24 7/167 Z 7/167 (72) Inventor Takatoshi Josugi Yokohama, Kanagawa 292, Yoshida-cho, Totsuka-ku, Ichitochi, Japan Multimedia System Development Headquarters, Hitachi, Ltd. (72) Inventor Tomoken Sato 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref. Inventor Masami Nishida 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Hitachi, Ltd.Video Information Media Division (72) Inventor Daimichi Tanaka 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Hitachi, Ltd.Video Information Media Division (72) Inventor Tohru Yamada 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Hitachi, Ltd.Space Technology Development Headquarters (72) Inventor Toshiyuki Tanaka 216 Totsuka-cho, Totsuka-cho, Yokohama, Kanagawa Originating Headquarters in

Claims (16)

[Claims] A scramble operation is performed using an operation result of two types of key data of a first key data and a second key data in order to scramble a part of digital data in an mpeg transport stream format. Content scrambling means, multiplexing means for time-division multiplexing the first key data, the second key data, and the output data stream of the content scrambling means in the form of an mpeg transport stream, and output of the multiplexing means. A transmitting apparatus comprising: a modulating unit that performs digital modulation such as multi-level QAM such as 64-level modulation; 2. A scramble operation is performed using an operation result of two types of key data of a first key data and a second key data in order to scramble a part of digital data in an mpeg transport stream format. Content scrambling means, multiplexing means for time-division multiplexing the output data stream of the content scrambling means in the form of an mpeg transport stream, and modulation means for digitally modulating the output of the multiplexing means with multi-level QAM such as 64-values Information storage means such as a semiconductor memory or an IC card capable of storing the first key data and the second key data; and a plurality of modulated waves including an output of the modulation means, frequency-multiplexed and transmitted to a transmission path. A transmitting device comprising: a signal synthesizing unit for transmitting; 3. A scramble operation is performed using an operation result of two types of key data of a first key data and a second key data in order to scramble a part of digital data in an mpeg transport stream format. Content scrambling means, multiplexing means for time-division multiplexing the output data stream of the content scrambling means in the form of an mpeg transport stream, and first modulating the output of the multiplexing means with digital modulation such as multi-level QAM such as 64 values. A second modulator for digitally modulating the first key data and the second key data with FSK or the like; an output of the first modulator and an output of the second modulator. And a signal synthesizing means for frequency-multiplexing a plurality of modulated waves including the modulated waves and transmitting the multiplexed waves to a transmission path. 4. A scrambling operation is performed using an operation result of two types of key data of a first key data and a second key data in order to scramble a part of digital data in an mpeg transport stream format. Content scrambling means; multiplexing means for time-division multiplexing either one of the first key data and the second key data and an output data stream of the content scrambling means in an mpeg transport stream format; Modulating means for digitally modulating the output of the means, such as multi-valued QAM such as 64 values, and information storage means such as a semiconductor memory or IC card capable of storing the first key data and the other of the second key data. A signal synthesizing means for frequency-multiplexing a plurality of modulated waves including the output of the modulation means and transmitting the multiplexed waves to a transmission path. A transmission device comprising a stage. 5. A scrambling operation using an operation result of two types of key data of a first key data and a second key data in order to scramble a part of digital data in an mpeg transport stream format. Content scrambling means; multiplexing means for time-division multiplexing either one of the first key data and the second key data and an output data stream of the content scrambling means in an mpeg transport stream format; First modulation means for digitally modulating the output of the means such as multi-valued QAM such as 64 values; andsecond modulation means for digitally modulating the other of the first key data and the other of the second key data with FSK or the like. A modulating means, a frequency multiplexing method for a plurality of modulated waves including the output of the first modulating means and the output of the second modulating means, Transmission apparatus and a signal synthesizing means for delivering. 6. A scrambling operation using an operation result of two types of key data of a first key data and a second key data in order to scramble a part of digital data in an mpeg transport stream format. Content scrambling means, multiplexing means for time-division multiplexing the output data stream of the content scrambling means in the form of an mpeg transport stream, and first modulating the output of the multiplexing means with digital modulation such as multi-level QAM such as 64 values. Modulation means for digitally modulating one of the first key data and the second key data by FSK or the like; andmodulation means for the first key data and the second key data. An information storage means such as a semiconductor memory or an IC card capable of storing the other one; and a plurality of modulated signals including an output of the modulation means. Transmission apparatus and a signal synthesizing means for delivering to the transmission line by frequency multiplexing. 7. A demodulation means for demodulating a digital modulated wave such as a multi-valued QAM such as 64 values transmitted by frequency multiplexing, and time-division multiplexed in an MPPEG transport stream format which is an output of said demodulation means. Time-division multiplexing / demultiplexing means for separating content-scrambled data, first key data, and second key data from the data, the first key data obtained by the time-division multiplexing / demultiplexing means, and the second A descrambling means for obtaining digital data in a transport stream format from the content scrambled data obtained by the demodulation means using the key data. 8. A demodulation means for demodulating a digital modulated wave such as a multi-valued QAM such as a 64 value transmitted in a frequency multiplexed manner, a semiconductor memory storing first key data and second key data, An information storage means such as an IC card; and a transport stream format digital signal obtained from the content-scrambled data obtained by the demodulation means by the first key data and the second key data obtained by the information storage means. A receiving device comprising: descrambling means for obtaining data. 9. A first demodulation means for demodulating a digital modulated wave such as a multi-valued QAM such as 64 values transmitted by frequency multiplexing, and a digital modulated wave such as FSK transmitted by frequency multiplexing. Second demodulation means for demodulating to obtain first key data or second key data, and the first key data and the second key data obtained by the second demodulation means for the first key data and the second key data. A descrambling means for obtaining transport stream digital data from the content scrambled data obtained by the demodulation means. 10. A demodulation means for demodulating a digital modulated wave such as a multi-valued QAM such as 64 values transmitted in a frequency multiplexed manner, and time-division multiplexed in an mpeg transport stream format which is an output of said demodulation means. Time-division multiplexing / demultiplexing means for separating one of the content-scrambled data and the first key data or the second key data from the data, and the other of the first key data or the second key data Information storage means such as a semiconductor memory or an IC card in which the first key data and the second key data obtained by the time division demultiplexing means and the information storage means are stored by the demodulation means. A descrambling means for obtaining transport stream digital data from the obtained content scrambled data. 11. A first demodulation means for demodulating a digital modulated wave such as a multi-valued QAM such as 64 values transmitted in a frequency multiplexed manner, and a digital modulated wave such as FSK transmitted in a frequency multiplexed manner. A second demodulation means for demodulating to obtain either the first key data or the second key data, and from time-division multiplexed data in an mpeg transport stream format which is an output of the first demodulation means. Time-division multiplexing / demultiplexing means for separating the content-scrambled data from the other of the first key data or the other of the second key data, obtained by the time-division multiplexing / demultiplexing means and the second demodulation means A descramble for obtaining digital data in a transport stream format from the content-scrambled data obtained by the demodulation means using the first key data and the second key data Receiver including a Le means. 12. A first demodulation means for demodulating a digitally modulated wave such as a multi-valued QAM such as 64 values transmitted in a frequency multiplexed manner, and a digital modulated wave such as FSK transmitted in a frequency multiplexed manner. A second demodulating means for demodulating to obtain either the first key data or the second key data; and a semiconductor memory storing the first key data or the other one of the second key data. Information storage means such as an IC card or an IC card; and the first key data and the second key data obtained by the information storage means and the second demodulation means.
A descrambling means for obtaining transport stream format digital data from the content scrambled data obtained by the demodulation means. 13. A transmitting apparatus for multiplexing and modulating digital data and transmitting the multiplexed data via a transmission path, wherein data relating to a program content among the digital data is scrambled by calculating a plurality of key data, and the plurality of key data are scrambled. A transmission device characterized in that the transmission device distributes the data without using the transmission device. 14. A receiving apparatus for receiving digital data via a transmission path and separating and demodulating the digital data, extracting a plurality of key data, and calculating data of the plurality of key data, the data relating to a program content scrambled among the digital data. Receiving apparatus for descrambling the data. 15. A receiving apparatus for receiving digital data via a transmission path and separating and demodulating the data, extracting a plurality of key data, and calculating data of the plurality of key data, the data relating to the program contents scrambled among the digital data. Receiving the descrambled program and outputting data relating to the descrambled program contents. 16. A transmitting apparatus for multiplexing and modulating digital data and transmitting the modulated data via a transmission path, scrambles data related to program contents among digital data by calculating a plurality of key data, and scrambles a plurality of key data. And a receiver for receiving and separating and demodulating digital data via a transmission path, extracting a plurality of key data, and calculating a plurality of key data to scramble the digital data. A transmission / reception system comprising a plurality of receiving apparatuses for descrambling data relating to contents and outputting data relating to descrambled program contents.