JP2001189921A - Limited reception system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a limited reception system and method, where contents transmitted from a broadcast center are relayed, without being descrambled by a relay device using a simple configuration and the relay device can uniquely manage the limited reception of a terminal. SOLUTION: In the case of relaying a broadcast signal from a broadcast center, since a CATV station encrypts information required for viewing part of signals, such as an ECM and an EMM with a unique encryption system, the CATV station can conduct unique view control, in spite of conducting retransmission, without descrambling the contents transmitted from the broadcast center using a simple configuration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conditional access system for conditional access to digital broadcasting.

[0002]

2. Description of the Related Art As a conventional technique for retransmitting a stream scrambled by a satellite broadcasting center or the like at a CATV station, only a part of program arrangement information is changed without performing descrambling and rescramble of contents. Pass-through system that re-transmits the stream and performs conditional reception under the control of the broadcast center, and re-multiplexing method that re-scrambles the content while adding the original conditional access information after descrambling once at the CATV station Two are known.

Hereinafter, a conventional technique will be described with reference to the drawings.

FIG. 14 is a diagram showing a main part of a system configuration of a pass-through system.

[0005] Satellite center 1401 and CATV station 1409
Are connected via a satellite line using satellite 1408, and CAT
A V station 1409 and a terminal device 1415 are connected by a CATV line.

In satellite center 1401, content server 1402 transmits content including video and audio to multiplexing unit 1403, and conditional access control unit 1404 scrambles the content with a determination area for determining permission to view the content. Scramble key (Ks)
A common information (ECM) having an ID is encrypted with a work key (Kw) and transmitted to the multiplexing unit 1403, and a contract information area and an EC for giving permission for each terminal device 1415 to view contents are provided.
Individual information (EMM) having Kw obtained by encrypting M is encrypted with a master key (Kmi) unique to each terminal device 1415 and transmitted to the multiplexing unit 1403.
405, an identifier (PID) for identifying the content to be scrambled and a scramble key (Ks) are transmitted.

[0007] The multiplexing device 1403 multiplexes the received content and ECM and EMM as one stream and transmits the multiplexed data to the scrambler 1405. The scrambler 1405 selects the content having the PID specified by the conditional access control unit 1404 from the received stream. Is scrambled and transmitted to the transmitting unit 1406. Transmission section 140
Reference numeral 6 performs transmission processing such as modulation according to a satellite line, and transmits the stream to the satellite line via a transmission antenna 1407.

[0008] In the CATV station 1409, the receiving unit 14
Numeral 11 receives a stream from a satellite line via a receiving antenna 1410, performs a receiving process such as demodulation, and transmits it to a PSI conversion unit 1412.

[0009] The PSI conversion unit 1412 stores a network management table (NIT) for transmitting information that is a part of the program sequence information (PSI) and associates transmission path information such as a modulation frequency with the content. Convert the usage to the usage for cable transmission and convert to QAM modulator 141
Send to 3.

[0010] A QAM modulator 1413 modulates the signal into a QAM method specified by CATV and transmits the modulated signal to a frequency converter 1414. The frequency converter 1414 converts the stream to a CATV transmission frequency and sends the stream to the CATV network.

[0011] The terminal device 1415 receives the stream from the CATV network, decodes the EMM addressed to itself, and holds the contract information and Kw. Then, when viewing the scrambled content, first, the ECM attached to the content is received and decoded with Kw, and the determination area in the ECM is compared with the contract information to check whether or not the viewing is permitted. If it is determined that the viewing permission is present, the content can be descrambled using Ks in the ECM, and the content can be viewed.

As described above, in the pass-through method, the CAT
The V station 1409 merely converts the stream into a modulation method suitable for the CATV network, and does not need to decode the ECM or EMM, and can relay the stream without involving the contents of the stream. In this method, the center device can be realized at a small scale and at low cost.
Viewing management based on conditional access at 415
401 performs.

FIG. 15 shows a CA as a remultiplexing repeater for adding unique conditional access information at a CATV station.
It is a figure which shows the principal part of a TV station.

Satellite center 1401 and CATV station 1409
Are connected via a satellite line using satellite 1408, and CAT
A V station 1409 and a terminal device 1415 are connected via a CATV network. Note that the satellite center 1401 is similar to the conventional pass-through system, and multiplexes and modulates key information and the like for determining content scrambling and permission to view the content, and then transmits the stream to the satellite line via the transmission antenna 1407. I do. The same applies to the operation of a terminal device (not shown). In addition, content, ECM, E
The relationship between MM and NIT is the same as that described above.

In the CATV station 1409, the receiving unit 14
10, 1411-1 to 1411-3 are the receiving antennas 14;
10, a stream is received from a satellite line, reception processing such as demodulation including scramble decoding is performed, and contents in a transport stream format are transmitted to the multiplexing unit 1501.

The multiplexing unit 1501 multiplexes a plurality of transport streams on one transmission line,
Program arrangement information (such as NIT) for V transmission, and ECM and EM transmitted from conditional access system 1502
M is multiplexed and sent to the scrambler 1503.

The scrambler 1503 scrambles the content having the PID similarly sent from the conditional access control unit 1502 using Ks sent from the conditional access control unit 1502, and transmits the scrambled content to the QAM modulator 1413.

A QAM modulator 1413 modulates the signal into a QAM method specified by CATV and transmits the modulated signal to a frequency converter 1414. The frequency converter 1414 converts the stream into a CATV signal.
And transmits it to the CATV network.

As described above, in the remultiplexing method, CA
While you can add your own conditional access to TV stations,
Once the stream transmitted from the satellite center 1401 has been demodulated into a transport stream format, it is necessary to add information related to conditional access in the same manner as in the broadcast center, which is a factor in increasing the size and cost of the entire system. become. In addition, it is necessary to manage viewing information about all customers in a CATV station, and there is a concern that a device for realizing a conditional access system will be enlarged.

[0020]

However, in the pass-through method in the above-mentioned conventional method, since the limited reception method in the broadcasting center is used as it is in the CATV terminal, the front end has a signal demodulation function corresponding to the CATV. If there is a CATV terminal that supports the same conditional access system and decoding function as the terminal directly receiving the demodulated signal, the user does not obtain the permission of the CATV operator,
It is possible to view the retransmitted content using the TV line. In other words, a user who does not know the CATV station
The ATV transmission line will be used, and not only will it not be possible to reliably collect fees from retransmitted viewers,
In the event of a failure, such as when noise affecting the entire CATV station is generated from a terminal device that is not understood, the CATV operator cannot respond as a facility manager,
It is required that the retransmission business operator performs its own viewing control.

Further, in the re-multiplexing method in the above-mentioned conventional method, it is necessary for the CATV station to independently manage all the customer information relating to the re-transmitting user, and at the same time, stream processing facilities such as descrambling and re-scramble are used. Therefore, it is necessary to install a conditional access system having the same function as that of the broadcasting center, which causes a large-scale facility and a high cost.

The present invention solves such a problem. In a CATV station as a relay device, only a terminal device permitted by the CATV station performs pass-through viewing of retransmitted content without descrambling the content. It is an object of the present invention to provide a conditional access system capable of performing the above, and an apparatus constituting the system.

[0023]

In order to solve the above-mentioned problems, a first invention (corresponding to claim 1) comprises a center device connected to a first transmission line, and the first transmission line. And one or more relay devices connected to the second transmission line, and one or more terminal devices connected to the second transmission line,
A conditional access system for performing limited reception of digital broadcasting, wherein the center device includes a scrambled content including at least one of video, audio, data, and a program, a scramble key for scrambling the content, and a scramble key for the content. Information obtained by encrypting the common information including the access determination area with the first encryption method,
A work key for encrypting the common information and information obtained by encrypting the individual information including the contract information of the terminal device by the first encryption method are multiplexed to form the first transmission path as a first stream. And the relay device encrypts the first stream received from the first transmission path by a second encryption method, and a second stream together with decryption information on the second encryption method. The terminal device transmits the second stream received from the second transmission line using the decryption information related to the second encryption method, and transmits the second encryption Decrypting the content using the first encryption method, and controlling access to the content based on the access determination area included in the common information and the contract information included in the individual information. Features It is a conditional access system to be.

As described above, in the first invention, limited reception is performed based on customer management information in the center device, and C
A viewing restriction unique to CATV can be added without performing descrambling and re-scrambling of the content on the ATV.

Further, the second invention (corresponding to claim 2)
Is a center device connected to the first transmission line, one or more relay devices connected to the first transmission line and the second transmission line, and one or more relay devices connected to the second transmission line. A conditional access system comprising at least one terminal device and limited reception of digital broadcasting, wherein the center device includes a scrambled content including at least one of video, audio, data, and a program, and Information obtained by encrypting a scramble key to be scrambled and common information including an access determination area for the content by a first encryption method, and a work key for encrypting the common information and a contract information including contract information of the terminal device. Information obtained by encrypting information using the first encryption method, and multiplexing the same and sending the multiplexed information as a first stream to the first transmission path. Received the first stream,
Encrypted by a second encryption method and sent out to the second transmission path as a second stream, the terminal device receives the second stream received from the second transmission path, a predetermined After decrypting with the second encryption method, decryption is performed with the first encryption method, and access to the content is performed based on the access determination area included in the common information and the contract information included in the individual information. It is a conditional access system characterized by performing control.

As described above, in the second invention, limited reception is performed based on customer management information in the center device, and C
A viewing restriction unique to CATV can be added without performing descrambling and re-scrambling of the content on the ATV. At this time, the decryption information relating to the second encryption method is stored in advance in a removable module such as an IC card or a storage unit built in the receiving device.

The third invention (corresponding to claim 3)
The relay device, of the first stream, the individual information encrypted by the first encryption method, further encrypted by the second encryption method, the second stream as Sending to the second transmission path, the terminal device,
The present invention according to the first or second aspect, wherein the individual information in the second stream is decrypted by the second encryption method, and then decrypted by the first encryption method. Is a conditional access system.

According to the third aspect of the present invention, among the information related to conditional access included in the stream transmitted through the first transmission line, in particular, the individual information (EMM) is transmitted to the regular CATV.
Only the contractor can decrypt the work key, and the work key for the retransmitted content can not be normally received by the unauthorized terminal, and the limited reception on the CATV can be performed by a simple method.

The fourth invention (corresponding to claim 4)
The relay device, of the first stream, the common information encrypted by the first encryption method, further encrypted by the second encryption method, as the second stream The terminal device sends the common information out of the second stream using the second encryption method, and then decrypts the common information using the first encryption method. A conditional access system according to the first or second aspect of the present invention.

As described above, in the fourth invention, among the information related to conditional access included in the stream transmitted through the first transmission path, particularly, the common information (ECM) is converted to the regular CATV.
Only the contractor can decrypt the content, and the scramble key for the retransmitted content can not be normally received by the unauthorized terminal, so that the limited reception on the CATV can be performed by a simple method.

The fifth invention (corresponding to claim 5)
The relay device, of the first stream, encrypts the program sequence information of the content by the second encryption method, and sends out the second stream as the second stream to the second transmission path, The terminal device according to the first or second, wherein, after decoding the program sequence information in the second stream using the second encryption method, decoding is performed using the first encryption method. 2 is a conditional access system according to the present invention.

According to the fifth aspect of the present invention, the program sequence information included in the stream transmitted through the first transmission path can be decrypted only by the authorized subscriber of CATV, and can be normally received by the unauthorized terminal. It is possible to prevent the processing from being performed, and it is possible to prevent unauthorized viewing of all retransmitted contents on CATV.

Further, a sixth aspect of the present invention (corresponding to claim 6)
The relay device has a function of adding frame packet information for multiplexing a plurality of transport streams to one transmission band, and encrypts the frame packet information by the second encryption method. The second stream is sent out to the second transmission path, and the terminal device decrypts the frame packet information in the second stream using a second encryption method, and then transmits the first encrypted The conditional access system according to the first or second aspect of the present invention, wherein decoding is performed by a system.

In the sixth aspect of the present invention, one CA
When a transport stream of a plurality of carriers exists on a TV line, information indicating the relationship between the transport stream ID and the digital packet information can be decrypted only by a CATV regular contractor, and an unauthorized terminal can receive normal information. Can be prevented from performing reception processing, and illegal viewing on CATV of retransmitted content provided by a plurality of operators on one channel can be prevented.

The seventh invention (corresponding to claim 7)
The relay device encrypts all signals including contents in the first stream using the second encryption method, and sends the encrypted signals to the second transmission path as the second stream. The terminal device decrypts all information including the content in the second stream using the second encryption method, and then performs decryption using the first encryption method. The conditional access system according to the first or second aspect of the present invention.

In the seventh aspect of the present invention, all streams are encrypted by the relay device, so that the CATV business operator can view and listen normally only to a user having a receiving device that is properly supported. And reception can be completely prevented by an unauthorized terminal.

The eighth invention (corresponding to claim 8)
The relay device has two or more encryption systems, and among the first streams, encrypts the individual information using a different encryption system for each transport stream, and the second stream Out to the second transmission path, the terminal device, among the second stream,
The conditional access system according to the first or second aspect of the present invention, wherein the individual information is decrypted using an encryption method for each transport stream, and then decryption of the first encryption method is performed. .

The ninth invention (corresponding to claim 9)
The relay device has two or more encryption systems, and among the first streams, encrypts the common information using a different encryption system for each transport stream, wherein the second stream Out to the second transmission path, the terminal device, among the second stream,
The conditional access system according to the first or second aspect of the present invention, wherein the common information is decrypted using an encryption method for each transport stream, and then decryption of the first encryption method is performed. .

In the eighth and ninth inventions as described above, in addition to the above, it is possible to further control whether or not viewing is possible for each transport stream broadcast at a CATV station.

According to a tenth aspect of the present invention (corresponding to claim 10), the relay device transmits the decryption information corresponding to the second encryption scheme to the second encryption scheme using a different frequency band from the content. The conditional access system according to the first aspect of the present invention, characterized in that the stream is transmitted to the second transmission path as a stream.

In the tenth aspect as described above, by transmitting information for decoding in a frequency band different from that of content transmission, the content to be retransmitted is not affected, and the content of the CATV station is not affected. Re-encryption can be performed.

According to the eleventh aspect, the information for decoding is transmitted in the same frequency band as the content transmission, so that there is no frequency band other than the stream for transmitting the content and the like, and there is no transmission / reception equipment. , CAT
The V station can be re-encrypted.

Also, according to an eleventh aspect of the present invention (corresponding to claim 11), the relay device transmits the decryption information corresponding to the second encryption scheme to the content using the same frequency band as the content. The conditional access system according to the first aspect of the present invention, characterized in that the stream is transmitted to the second transmission path as a second stream.

According to a twelfth aspect of the present invention (corresponding to claim 12), the relay device includes, in the information of the frame packet, decryption information corresponding to the second encryption. The conditional access system according to the first aspect of the present invention, wherein the stream is transmitted to the second transmission path as a stream.

In the twelfth aspect as described above, when transmitting a plurality of streams on one channel, it is possible to effectively utilize frame packet information which must be added without fail.

According to a thirteenth aspect of the present invention (corresponding to claim 13), the terminal device comprises a first conditional access module for the first encryption scheme and a second conditional access module for the second encryption scheme. Having the second conditional access module, after decoding the second stream received via the second transmission path in the second conditional access module, in the first conditional access module The conditional access system according to the first or second aspect of the present invention, wherein decoding is performed.

In the thirteenth aspect as described above, the terminal device has two modules: a module for decrypting the first encryption method and a module for decrypting the second encryption method. In such a case, the configuration and processing method can be defined.

A fourteenth aspect of the present invention (corresponding to claim 14) relates to the conditional access system according to any one of the first to thirteenth aspects of the present invention. Alternatively, the present invention is a program recording medium that records a program and / or data for executing a part of the functions by a computer, and is readable by a computer.

[0049]

Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited to these embodiments at all, and can be implemented in various modes without departing from the gist thereof.

(First Embodiment) In the first embodiment, satellite broadcasting, which is an example of a conditional access system, is a CAT.
A digital broadcasting system for relaying and broadcasting at the V station will be described with reference to FIGS.

FIG. 1 is a block diagram showing the entire configuration of the conditional access system according to the present embodiment.

The broadcasting center 101 and the CATV station 105 are connected by a satellite line 102 using an artificial satellite 103, and the broadcasting center 101 and the direct receiving terminal 104 are also connected by the satellite line 102. Furthermore, CATV station 105 and CATV
Terminal 107 is connected by CATV line 106.

The broadcast center 101 transmits the broadcast wave to the satellite line 1
02, and the direct receiving terminal 104 directly receives radio waves from the satellite line 102. CATV station 105 is satellite line 1
02 is relayed to the CATV line 106, and the CATV terminal 107 receives the broadcast wave from the CATV line 106.

FIG. 2 is an example of a block diagram showing a main part of the internal configuration of the broadcast center 101.

The broadcast center 101 includes a content server 201 for transmitting contents including video and audio,
The Kw management unit 203 that holds w (work key) and the contract information of Kw and the direct receiving terminal 104 are stored in EMM (individual information).
And a Kmi (master key) unique to the receiving terminal device directly
EMM generation unit 202 that encrypts with
A Ks generation unit 205 that generates a (scramble key) and transmits a Ks and a packet identifier (PID) of the content to be scrambled to the scrambler 207;
And an ECM generation unit 204 that stores the viewing determination information of the content targeted for conditional access in the ECM and encrypts the content using Kw, and a multiplexing unit 206 that multiplexes the content, the EMM, and the ECM and outputs it as a transport stream. ,
A scrambler 207 for scrambling the packet of the content in the transport stream using Ks;
Transmitter 2 that performs processing such as modulation according to satellite link 102
08, and an antenna 209 for transmitting a transport stream to the satellite line 102 as broadcast radio waves.

The contents server 201 transmits contents including video and audio to the multiplexing unit 206 in the transport stream format of the MPEG2 standard. The Kw management unit 203 holds Kw, transmits Kw to the EMM generation unit 202 and the ECM generation unit 204, and
2 is an EMM for Kw and the contract information of the direct receiving terminal 104.
And the area to be encrypted of the EMM is encrypted with the Kmi unique to the receiving terminal device, and transmitted to the multiplexing unit 206. The Ks generation unit 205 generates Ks at regular intervals,
To the M generation unit 204, and the ECM generation unit 204
In addition, the viewing determination information of the content to be limited reception is stored in the ECM, the area to be encrypted of the ECM is encrypted using Kw, and the encrypted area is transmitted to the multiplexing unit 206. The scrambler 207, to which the Ks and the PID of the content to be scrambled have been transmitted from the Ks generation unit 205, scrambles the transport stream transmitted from the multiplexing unit 206 and transmits it to the transmission unit 208. The transmission unit 208 performs processing such as modulation according to the satellite link 102 and sends out a transport stream to the satellite link 102 via the transmission antenna 209 as broadcast radio waves.

FIG. 3 is an example of a block diagram showing a main part of the internal configuration of the CATV station 105.

The CATV station 105 includes a receiving antenna 301 for receiving a broadcast wave from the satellite line 102, a receiving section 302 for demodulating a received signal, and a PSI converting section for converting program sequence information into a cable transmission use. 303 and P
Re-encryption unit 3 for encrypting a corresponding area in the transport stream format signal from SI conversion unit 303
04, a re-encryption management unit 305 that generates and stores encryption conditions for re-encryption, and a transport stream input from the re-encryption unit 304, multiplexes the encryption information input from the re-encryption management unit 305, and A multiplexing unit 306 for converting two transport streams, a QAM modulating unit 307 for performing modulation on the transport stream according to the CATV line 106, a frequency converting unit 308 for converting the transport stream into a frequency band to be transmitted, Mixing unit 3 for sending a stream to CATV line 106
09.

The receiving section 302 receives a broadcast wave from the satellite line 102 via the receiving antenna 301, performs processing such as demodulation, and converts the transport stream to be relayed to the PS.
Transmit to I conversion section 303. PSI conversion unit 303 is NI
A part of the program arrangement information such as T
The data is converted into a use for CATV transmission and transmitted to the re-encryption unit 304. The re-encryption unit 304 performs re-encryption processing on an area (for example, a packet having a specific PID) to be re-encrypted by the re-encryption management unit 305, and
Send to 6. The multiplexing unit 306 multiplexes the transport stream after re-encryption with the key information for decrypting the re-encryption in the CATV terminal 107 sent from the re-encryption management unit 305, and performs QAM as one transport stream. The signal is transmitted to the modulation unit 307. The QAM modulator 307 converts the transport stream into the CATV line 10
6 and transmits it to the frequency conversion unit 308. The frequency conversion unit 308 converts the transport stream into a frequency band to be transmitted and transmits it to the mixing unit 309. The mixing unit 309 converts the transport stream into broadcast radio waves. As C
The data is transmitted to the ATV line 106.

FIG. 4 is an example of a block diagram showing a main part of the internal configuration of the direct receiving terminal 104.

A direct receiving terminal 104 includes a tuner 402 for receiving a broadcast wave selected from a satellite line 102 via a receiving antenna 401, a demodulator 403 for performing demodulation processing on a received transport stream, and an EMM and an EMM from the transport stream. A separating unit 404 for separating the ECM from the others, a conditional access module 405 for decrypting the EMM to extract the contract information and Kw, and decrypting with the Kw to extract the viewing permission information and Ks, and using the extracted Ks It includes a descrambler 406 for descrambling the packet of the content in the transport stream, and an output control unit 407 for converting the content into a signal according to the output mode.

The tuner 402 of the direct receiving terminal 104
Receives a broadcast radio wave from the satellite line 102 via the reception antenna 401 and transmits a transport stream to be received to the demodulation unit 403. The demodulation unit 403 performs demodulation processing corresponding to the broadcast center 101 on the transport stream, and transmits the transport stream to the separation unit 404. The separation unit 404 separates the EMM and the ECM from the transport stream and transmits the EMM and the ECM to the conditional access module 405, The remaining transport streams are transmitted to the descrambler 406. The conditional access module 405 decrypts the EMM using Kmi that is stored in advance, extracts and stores the contract information and Kw, and decrypts the received ECM using Kw,
The viewing determination information and Ks are extracted, and the contract information is compared with the viewing determination information. If it is determined that viewing is possible, Ks is transmitted to the descrambler 406. The descrambler 406 descrambles the packet of the content in the transport stream using Ks and transmits the descrambled packet to the output control unit 407. The output control unit 407 performs processing such as converting the content into a signal corresponding to the output mode. And send it to the receiver.

FIG. 5 is an example of a block diagram showing a main part of the internal configuration of CATV terminal 107.

The CATV terminal 107 is connected to the CATV line 10
6, a tuner 501 that receives a broadcast signal from the CTV 6, a demodulation unit 502 that performs demodulation processing on the received transport stream and sends it to a re-encryption / decryption management unit 504 for decoding a re-encryption scheme, and a CATV station 105. A re-encryption / decryption unit 503 that performs decryption according to the encryption method, a re-encryption / decryption management unit 504 that extracts key information for re-encryption and sends it to the re-encryption / decryption unit 503, Separation unit 505 for separating others
And a conditional access module 506 that decodes the EMM to extract the contract information and the first Kw, and decodes the KMM to extract the viewing determination information and the Ks, and the content in the transport stream using the extracted Ks. A descrambler 507 for descrambling the packet of the above, and an output control unit 508 for converting the content into a signal corresponding to the output form.

The tuner 501 of the CATV terminal 107
Receives a broadcast wave from the CATV line 106 and transmits a transport stream to be received to the demodulation unit 502. The demodulation unit 502 performs demodulation processing corresponding to the broadcast center 101 on the transport stream, and transmits the transport stream to the re-encryption / decryption unit 503 and the re-encryption / decryption management unit 504. The re-encryption / decryption management unit 504 extracts information for decryption processing corresponding to the re-encryption management unit 504 in the CATV station 105,
This is transmitted to the re-encryption / decryption unit 503. The re-encryption / decryption unit 503 performs a decryption process corresponding to the re-encryption unit 304 in the CATV station 105 using the key information and transmits the result to the demultiplexing unit 505.
The MM and the ECM are separated and transmitted to the conditional access module 506, and the remaining transport stream is transmitted to the descrambler 507. The conditional access module 506 includes:
The EMM is decrypted using Kmi that is stored in advance, and the contract information and Kw are extracted and stored. When the ECM is received, the EMM is decrypted using Kw, and the viewing determination information and Ks are extracted. The information is compared with the information, and if it is determined that viewing is possible, Ks is transmitted to the descrambler 507. The descrambler 507 descrambles the packet of the content in the transport stream using Ks, transmits the descrambled packet to the output control unit 508, and outputs the descrambled packet to the output control unit 508.
Performs processing such as converting the content into a signal corresponding to the output form, and sends the signal to a receiver or the like.

The operation of the conditional access system having the above configuration will be described below.

In the broadcast center 101, the content server 201 sends out one or more contents. The contents are in the MPEG2 transport stream format, and all audio and video included in the contents are transmitted in the packet format. Further, one or more contents are included in one transport stream, and a set of transport streams is expressed as a channel. It is assumed that the content server 201 also sends out the program arrangement information (PSI) for indicating the configuration of the channel, that is, the configuration of the packet included in each content.

The Kw management unit 203 stores the Kw and the paired KwID in the EMM generation unit 202 and the ECM generation unit 2.
04.

The EMM generating unit 202 is connected to each of the direct receiving terminals 10
4 and an EMM to the CATV terminal 107.
The basic configuration of the EMM is as shown in FIG.
1, a KwID 602, a Kw storage area 603, and a contract information area 604. The terminal ID 601 is a terminal ID (identification number) unique to each of the direct receiving terminals 104 that is a destination of the EMM.
Is stored in the KwID 602, and a KwID (work key identification) 602 for identifying each Kw when two or more Kw are required when changing the Kw, for example, is stored in the Kw storage area 603. The Kw itself, which is paired with the KwID stored in the KwID 602, is stored, and the contract information of the direct receiving terminal 104 corresponding to the terminal ID stored in the terminal ID 601 is stored in the contract information area 604. The KwID 602, the Kw storage area 603, and the contract information area 604 correspond to the direct receiving terminal 104 corresponding to the terminal ID.
Encrypt with a unique Kmi (master key). The EMM generation unit 202 generates and transmits such an EMM.

The ECM generation unit 204 includes a Ks generation unit 205
Generates and sends an ECM attached to the content.
The basic configuration of the ECM is as shown in FIG.
1, a Ks storage area 702 and a viewing determination area 703 are included.
Describing the ECM, KwID 701 is an identifier of Kw for encrypting the ECM, and KwID6 in the EMM.
02. The Ks storage area 702 stores Ks for scrambling the content, and the viewing determination area 703 stores information for determining viewing of the content. Further, the Ks storage area 702 and the viewing determination area
The encryption is performed using the Kw paired with the KwID stored in the wID 701.

The multiplexing unit 206 multiplexes the contents, the EMM and the ECM, and transmits the multiplexed data as one transport stream. The scrambler 210 uses the specified PID to transmit the content to be scrambled in the transport stream. Is transmitted after being scrambled and transmitted as a broadcast wave to the satellite line 102 via the transmission unit 208 and the transmission antenna 209.

In the CATV station 105, the PSI conversion section 303 performs transmission channel physical information such as frequency band and modulation scheme on the satellite line in the received transport stream, and logical information for program selection by the CATV terminal 107. Are described, and based on this information, the broadcast wave 1
02, it is possible to receive an appropriate transport stream. This PSI is the CATV
Since the transport stream cannot be received by the CATV terminal 107 after relaying to the line 106, the CATV terminal 10
Change to a content suitable for 6.

Re-encryption management section 305 in CATV station 105
Holds conditions such as key information for performing re-encryption of the baseband-level transport stream after PSI conversion using a CATV station's own encryption method, and multiplexes the information into the re-encryption management unit 304. The key information is transmitted to the unit 306.

The re-encryption unit 304 performs CATV-specific re-encryption processing for each CATV terminal 107. If it is assumed that the area to be re-encrypted is EMM information, the processing will be described with reference to FIG. The terminal ID 601 stores a terminal ID unique to the CATV terminal 107 from the broadcast center 101, and the Kw ID 602 stores Kw for identifying Kw.
In the contract information area 604, the terminal ID 601 is stored.
The contract information of the CATV terminal 107 corresponding to the terminal ID stored in is stored. Further, the KwID 602 and the contract information area 604 correspond to the CATV terminal 107 corresponding to the terminal ID.
After being encrypted by the unique Kmi and transmitted through the satellite line 102, the re-encryption unit 304 in the CATV station 105 re-encrypts the encryption unit 604 in the EMM.

The multiplexing unit 306 further multiplexes the key information for re-encryption into the transport stream, and transmits the transport stream as one transport stream.
7, CAT via frequency conversion section 308 and mixing section 309
It is transmitted to the V line 106 as a broadcast wave.

[0076] Direct receiving terminal 104 receives a transport stream containing the content to be viewed directly from satellite line 102 via receiving antenna 401, tuner 402 and demodulating section 403, and demultiplexing section 404 converts the transport stream into an ECM and its own. EMM addressed to
Are separated and transmitted to the conditional access module 405.

The conditional access module 405 transmits Ks to the descrambler 405 when it is determined that viewing is possible by comparing the contract information of the EMM with the viewing determination information (not shown) of the ECM. The flowchart shown in FIG. 8 shows basic viewing determination processing, which is basic processing of the conditional access module 405 and the conditional access module 506. First, the conditional access module 405 will be described. When the EMM contracts, it is received in advance, decrypted using Kmi, and Kw
ID, Kw, and contract information are held. Step 8
At 01, the ECM is received, and the encryption unit is decrypted using the corresponding Kw based on the KwID of the non-encryption unit. In step 802, if the decrypted viewing determination information is compared with the contract information stored in advance to determine that viewing is possible, the process proceeds to step 803, where Ks is transmitted to the descrambler 406, and it is determined that viewing is not possible. If it moves to step 804,
Error processing, for example, replying that the contract has not been made is performed.

In the CATV terminal 107, the tuner 5
01 and the transport stream including the content to be viewed from the CATV line 106 via the demodulation unit 502, and the demodulation unit 502 demodulates the transport stream according to the transmission method according to the CATV station 105, and re-encrypts the transport stream. And to the re-encryption / decryption management unit 504. The re-encryption / decryption management unit 504 extracts key information for decryption from the input transport stream, and transmits the key information to the re-encryption / decryption unit 503. Re-encryption / decryption unit 50
3 decrypts the encryption scheme uniquely added by the CATV station 105 based on the key information input from the re-encryption / decryption management unit 504, and outputs the decrypted data to the output of the scrambler 207 in the broadcast center 101. The same transport stream is transmitted to the separation unit 505. The separating unit 505 separates the ECM and the EMM addressed to itself from the transport stream, and transmits them to the conditional access module 506.

The conditional access module 506 transmits Ks to the descrambler 507 when it is determined that viewing is possible by comparing the contract information of the EMM and the viewing determination information of the ECM. More specifically, the determination process is the same as the above-described flowchart of FIG. 8, in which the EMM has been received in advance, decrypted using Kmi, and holds KwID, Kw, and contract information. In step 801, the ECM is received, and the encryption unit is decrypted using the corresponding Kw based on the KwID of the non-encryption unit. In step 802, if the decrypted viewing determination information is compared with the contract information held in advance to determine that viewing is possible, the process proceeds to step 803, where Ks is transmitted to the descrambler 505, and it is determined that viewing is not possible. Step 80
Then, the process proceeds to step 4 to perform error processing, for example, replying that a contract has not been made.

As described above, according to the present embodiment, the broadcast center 101 sends out ECM and ECM along with the content, and the CATV station 105 converts the corresponding area of the transport stream received from the broadcast center 101 into the second cipher. Re-encrypted by the encryption scheme and sent out,
Uses the ECM and EMM of the stream transmitted by the satellite line 102 that has not been re-encrypted, while the CATV terminal 107
Then, after decoding the corresponding area in the stream transmitted by the CATV line 106 using the second encryption method, the viewing / listening determination for the content is performed using the ECM and the EMM in the same process as the direct receiving terminal 104. Therefore, in addition to the broadcast center 101 managing the conditional access to the CATV terminal 107 similarly to the direct receiving terminal 104, the CATV station 105 can independently control the viewing of the CATV terminal. Can be

Further, since the CATV station 105 does not need to perform descrambling of the content and decoding of the ECM and EMM when relaying the information including the content, the relay can be performed with a simple configuration, and the equipment can be relayed. Cost reduction can be achieved.

The area where re-encryption is performed by the re-encryption unit 304 in the CATV station 105 includes not only the EMM encryption unit illustrated in FIG. 6 but also the ECM encryption unit illustrated in FIG. Part or all of 702 to 703 can be re-encrypted.

Further, as an area where re-encryption is performed by the re-encryption unit 304 in the CATV station 105, re-encryption may be performed on the program sequence information and the entire stream.

Further, the CATV station 105 uses a plurality of encryption schemes for re-encryption, performs encryption in a different scheme for each transport stream,
In 7, the decoding may be performed by the corresponding method. In addition to transport streams,
The encryption processing may be performed for each content constituting the transport stream.

Further, in the present embodiment, the case where the key information for re-encryption is multiplexed on the stream has been described, but the key information for re-encryption is transmitted in a frequency band different from that of the transport stream. You can also.

Also, the key information for re-encryption is CAT
A case has been described in which the re-encryption management unit 305 in the V station 105 generates the data and multiplexes it into another stream in the multiplexing unit 306.
06, and the CATV terminal 1 using a separate storage medium.
07, the CATV terminal 107 can acquire key information for re-encryption in advance.

The conditional access modules 405 and 5
07 may be a built-in chip, a removable IC card, a PCMCIA card, or the like.

Further, it is not always necessary to use an encryption method using key information as an encryption method for re-encryption, and an encryption method defined in advance may be used.

Further, the re-encryption / decryption unit 503 and the re-encryption / decryption management unit 504 in the CATV terminal 107 may be configured as a single module as indicated by 901 in FIG. Further, as a method of realizing these, a built-in chip may be used, or a detachable IC may be used.
A card or a PCMCIA card may be used.

(Second Embodiment) In the second embodiment, a satellite broadcast, which is an example of a conditional access system, is a CAT
Regarding a digital broadcasting system for broadcasting by broadcasting at a V station,
In particular, in the case where a plurality of transport streams are multiplexed and transmitted in one channel, FIGS.
This will be described with reference to FIG.

FIG. 10 is a diagram for explaining the concept of multiplexing a plurality of transport streams on one channel in the present embodiment.

When retransmitting the content from the broadcast center 101, the CATV station 105 transmits the
6, at least three transport streams of a transport stream 1 (TS1) 1002, a transport stream 2 (TS2) 1003, and a transport stream 3 (TS3) 1004 are transmitted to a specific channel 1001. In addition, CATV
In the terminal 1007, a tuner 501 for reception processing
It has a function of extracting a specific transport stream from one channel.

FIG. 11 is a diagram showing an example of frame packet information for multiplexing a plurality of transport streams on one channel.

In the digital broadcasting system, contents and the like are transmitted in a set of fixed-length information called a packet. The number for distinguishing this packet is called a packet number. When the transport stream is an MPEG2 transport stream, this packet number is the PID described in the header of the transport packet. When a plurality of transport streams are transmitted, a number for distinguishing each is called a transport stream ID. The frame packet information indicates such a relationship, and one example thereof has a format shown in FIG. 11, and the frame packet information is further transmitted as a digital packet to which a specific packet number is added.

FIG. 12 is an example of a block diagram showing a main part of the internal configuration of CATV station 105.

The CATV station 105 includes a receiving antenna 301 for receiving a broadcast wave from the satellite line 102, a receiving section 302 for demodulating a received signal, and a PSI converting section for converting program arrangement information into a cable transmission use. 303 and P
From the signal in the transport stream format from the SI converter 303, frame packet information for transmitting a plurality of transport streams on one channel is generated, multiplexed with the transport stream, and re-encrypted.
05, and a re-encryption unit 304 for encrypting a corresponding area in the transport stream from the frame information generation unit 1201.
The key information input from the re-encryption management unit 305 is multiplexed with the re-encryption management unit 305 that generates the encryption condition / key information in the re-encryption, and the transport stream input from the re-encryption unit 304. A multiplexing unit 306 for forming one transport stream; a QAM modulator 307 for performing modulation on the transport stream according to the CATV line 106; a frequency converter 308 for converting the transport stream into a frequency band to be transmitted; Mixing unit 30 for sending a port stream to CATV line 106
9 is provided.

The operation of the conditional access system having the above configuration will be described below.

The operation of the broadcast center 101 in FIG. 2 is the same as that of the first embodiment, and sends out the scrambled content, PSI, ECM and EMM information. In the CATV station 105, the PSI conversion unit 303 converts the satellite line 102 in the received transport stream.
It describes the physical information of the transmission path such as the frequency band and the modulation method in the, and the logical information for selecting the program in the CATV terminal 107. Based on this information, an appropriate transport stream is received from the broadcast wave 102. It is possible to do. This PSI is used as is in CAT
Since the transport stream cannot be received by the CATV terminal 107 after relaying to the V line 106, the CATV terminal 107
Change to a content suitable for 6. Frame information generation unit 120
1 generates frame packet information shown as an example in FIG. 11 for inputting a plurality of transport streams in the PSI conversion unit 303 and transmitting the stream on one channel. The frame packet information includes a packet number 1101 and a transport stream ID 110.
2, when a plurality of packets with identification numbers are transmitted according to the digital broadcasting system, a comparison table between the packet number 1101 and the transport stream number 1102 is described. At the same time as generating such information, the re-encryption unit 304
Is added to the transport stream and transmitted.

The re-encryption management section 305 holds initial values and conditions for re-encrypting the baseband signal after the PSI conversion by the CATV station's own encryption scheme. , And transmits key information for re-encryption to multiplexing section 306.

The re-encryption unit 304 performs a CATV-specific re-encryption process for each CATV terminal 107 in the area such as the frame packet information as in the first embodiment.

The multiplexing unit 306 further multiplexes the key information for re-encryption into the transport stream, and sends out the transport stream as one transport stream.
7, CAT via frequency conversion section 308 and mixing section 309
It is transmitted to the V line 106 as a broadcast wave.

Tuner 5 in CATV terminal 107
01, after selecting a specific channel, selecting and receiving a transport stream including the content to be viewed and outputting it to the re-encryption / decryption unit 503 and the re-encryption / decryption management unit 504. Separation unit 5
05 to the output control unit 508 are performed.

As described above, according to the present embodiment, CA
A plurality of transport streams and frame packet information are transmitted from the TV station 105 in one channel by CAT.
After transmitting to the V transmission path 106, the CATV terminal 107 decrypts the content using the re-encryption method, and then performs the viewing determination on the content using the ECM and EMM using the same encryption method of the broadcast center 101 as the direct reception terminal 104. Broadcast center 101, as well as direct receiving terminal 104,
In addition to managing conditional access to the ATV terminal 107, the CATV station 105 can independently manage conditional access to the CATV terminal.

In the present embodiment, the case where frame packet information is used as a region for re-encryption has been described. However, re-encryption may be performed on the entire stream including ECM, EMM, program sequence information, and content. Absent.

Although the case where the re-encryption key information is multiplexed into the stream has been described, it can be described in the same area as the frame packet information and transmitted to the CATV terminal 107.

Further, CATV station 105 employs a plurality of encryption schemes for re-encryption, performs encryption in different schemes for each transport stream, and CATV terminal 107 performs decryption in a corresponding scheme. You can go. In addition to transport streams,
The encryption processing may be performed for each content constituting the transport stream.

Further, in the present embodiment, a case has been described in which key information for re-encryption is multiplexed on a stream, but key information for re-encryption is transmitted in a frequency band different from that of a transport stream. You can also.

Also, the key information for re-encryption is CAT
A case has been described in which the re-encryption management unit 305 in the V station 105 generates the data and multiplexes it into another stream in the multiplexing unit 306.
06, and the CATV terminal 1 using a separate storage medium.
07, the key information for re-encryption can be obtained and used in advance at the CATV terminal 107.

The conditional access modules 405 and 5
06 may be a built-in chip, a removable IC card, a PCMCIA card, or the like.

Further, it is not always necessary to use an encryption method using key information as an encryption method for re-encryption, and an encryption method defined in advance may be used.

Further, the re-encryption / decryption unit 503 and the re-encryption / decryption management unit 504 in the CATV terminal 107 may be configured as a single module as shown by 901 in FIG. Further, as a method of realizing these, a built-in chip may be used, or a detachable IC may be used.
A card or a PCMCIA card may be used.

(Third Embodiment) In a third embodiment, the configuration and operation of a CATV terminal that realizes a conditional access system will be described with reference to FIG.

FIG. 13 is an example of a block diagram showing a main part of an internal configuration of the CATV terminal 107 for realizing the conditional access system according to the present embodiment.

The CATV terminal 107 is connected to the CATV line 10
6 and a demodulator 501 for receiving a broadcast signal and performing demodulation processing on the received transport stream.
The demodulation unit 502 for transmitting information including key information necessary for re-encryption and decryption to the re-encryption and decryption management unit, and the part for performing re-encryption and decryption including the area encrypted by the CATV station 105 are separated. Separation unit 13 for transmitting to re-encryption / decryption unit 1303
01 and the separated re-encrypted area and the re-
The decryption unit 13 that decrypts the decryption information based on the decryption information from the broadcast center 04 and transmits the decryption information to the conditional access module 1305 that decrypts the encryption method according to the broadcast center 101.
03 and the key information after re-encryption and decryption, and extracts key information such as Ks for descrambling in the same manner as above.
Conditional reception module 1 for transmitting to descrambler 507
305, a descrambler 507 for descrambling the packet of the content in the transport stream using the extracted Ks, and an output control unit 508 for converting the content into a signal corresponding to the output format. The re-encryption / decryption unit 1303 and the re-encryption / decryption management unit 130
4 are collectively referred to as a re-encryption module 1302.

The operation of the conditional access system having the CATV terminal 107 having the above configuration will be described below.

The flow of processing from the broadcast center 101 to the satellite link 102, from the satellite link 102 to the CATV station 105, and from the CATV station to the CATV link 106 is as described above and will not be described in particular. In response to the partially re-encrypted stream transmitted from the broadcast center 101 and transmitted by the CATV line 106, the CATV terminal 107 transmits the CATV line 1 via the tuner 501 and the demodulation unit 502.
06, a transport stream including the content to be viewed is received.
, And transmits the transport stream to the separation unit 1301 and the re-encryption / decryption management unit 1304. The separation unit 1301 separates the re-encrypted ECM or the EMM addressed to itself from the transport stream and transmits the ECM to the re-encryption module 1302. The re-encryption / decryption management unit 1304 in the re-encryption module 1302 extracts key information for decryption from the input transport stream, and transmits the key information to the re-encryption / decryption unit 1303. The re-encryption / decryption unit 1303
CATV station 105 performs decryption based on the key information input from CATV station 4 using the encryption method uniquely added to the CATV station 105, and outputs the same transport stream as the output of scrambler 207 in broadcast center 101 as a conditional access module. 1305
Send to The conditional access module 1305 transmits Ks to the descrambler 507 when the broadcast center 101 compares the contract information of the EMM and the viewing determination information of the ECM to determine that viewing is possible.

As described above, according to the present embodiment, broadcast center 101 sends out ECM and ECM along with the content, and CATV station 105 re-encrypts the corresponding portion of the transport stream received from broadcast center 101. After transmitting, the CATV terminal 107 decrypts the area encrypted by the second encryption method as the re-encryption method, and then uses the ECM and EMM in the same encryption method of the broadcast center 101 as the direct reception terminal 104. The CATV terminal 1 determines whether the content has been viewed.
07, the re-encryption module 1302 and the conditional access module can be completely independent.

In the present embodiment, CATV terminal 1
At 07, the demodulation unit 502 sends key information for re-encryption to the re-encryption / decryption management unit 1304.
The same processing can be performed by the separation unit 1301.

Further, as the re-encryption method, not only a method using a key but also an encryption method using no key may be performed.

The broadcasting center of the present embodiment is an example of the center device of the present invention, the CATV station of the present embodiment is an example of the relay device of the present invention, and the CATV station of the present embodiment.
The terminal is an example of the terminal device of the present invention, the satellite line of the present embodiment is an example of the first transmission line of the present invention, and the CATV line of the present embodiment is a terminal of the second transmission line of the present invention. It is an example.
The transport stream of the present embodiment is an example of the first stream of the present invention, and the transport stream of the present embodiment is an example of the second stream of the present invention.

Further, the present invention is a program recording medium which records a program and / or data for causing a computer to execute all or a part of the functions of the conditional access system of the present invention, and is readable by the computer. Also, a program recording medium characterized in that the read program and / or data cooperates with the computer to execute the function also belongs to the present invention.

[0122]

As is clear from the above description, in the conditional access system of the present invention, when a CATV station relays a broadcast signal, the CATV station transmits the ECM, EMM or program arrangement information necessary for viewing the signal to the CATV station. Since it has a configuration of encrypting with a station-specific encryption method, the CATV station can also independently control the viewing of the terminal device even in the pass-through method.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a conditional access system according to a first embodiment of the present invention.

FIG. 2 is an internal configuration diagram of a broadcast center according to the first embodiment of the present invention.

FIG. 3 is an internal configuration diagram of a CATV station according to the first embodiment of the present invention.

FIG. 4 is an internal configuration diagram of a direct receiving terminal according to the first embodiment of the present invention.

FIG. 5 is an internal configuration diagram of the CATV terminal according to the first embodiment of the present invention.

FIG. 6 is a basic configuration diagram of an EMM according to the first embodiment of the present invention.

FIG. 7 is a basic configuration diagram of an ECM according to the first embodiment of the present invention.

FIG. 8 is a diagram showing an operation of the conditional access module according to the first embodiment of the present invention.

FIG. 9 is an internal configuration diagram of the CATV terminal according to the first embodiment of the present invention.

FIG. 10 is a diagram illustrating multiple transport stream multiplexing according to the second embodiment of the present invention.

FIG. 11 is a diagram illustrating a basic configuration of frame packet information according to a second embodiment of the present invention;

FIG. 12 shows a CATV according to the second embodiment of the present invention.
Station internal configuration diagram

FIG. 13 shows a CATV according to the third embodiment of the present invention.
Terminal internal configuration diagram

FIG. 14 is a diagram illustrating a conventional pass-through method.

FIG. 15 is a diagram illustrating a conventional remultiplexing method.

[Explanation of symbols]

 101, 1401 Broadcasting center 102 Satellite line 103 Artificial satellite 104 Direct reception terminal 105 CATV station 106 CATV line 107, 1415 CATV terminal 201 Content server 202 EMM generation unit 203 Kw generation unit 204 ECM generation unit 205 Ks generation unit 206, 1501 Multiplex unit 207, 406, 507, 1405 Scrambler 208, 1406 Transmitting unit 301, 401, 1410 Receiving antenna 302, 1411 Receiving unit 303, 1412 PSI converting unit 304, 1303 Re-cipher decoding unit 305, 1304 Re-cipher management unit 306, 1403 Multiplexing Units 307, 1413, QAM modulation units 308, 1414 frequency conversion units 309 mixing units 402, 501 tuners 403, 502 demodulation units 404, 505 separation units 405, 506, 130 Conditional reception modules 407, 508 Output control unit 503 Re-encryption / decryption unit 504 Re-encryption / decryption management unit 601 Terminal ID 602, 701 KwID 603 Kw storage area 604 Contract information area 702 Ks storage area 703 Viewing determination area 901, 1302 Re-encryption / decryption module 1201 Frame information generation unit 1402 Content server 1404, 1502 Conditional reception control unit 1407 Transmission antenna

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Atsunori Sakurai 1006 Kadoma Kadoma, Osaka Pref.Matsushita Electric Industrial Co., Ltd. Term (reference) 5C064 BA01 BB05 BB07 BC07 BC11 BC17 BC22 BD02 BD07 BD08 5J104 AA01 AA16 BA02 EA04 EA06 EA17 JA03 NA02 NA03 NA35 NA41 PA06

Claims (14)

[Claims] 1. A center device connected to a first transmission line, one or more relay devices connected to the first transmission line and a second transmission line, and a connection to the second transmission line A limited reception system for performing limited reception of digital broadcasting, comprising: at least one terminal device, wherein the center device includes: a scrambled content including at least one of video, audio, data, and a program; Information obtained by encrypting a scramble key for scrambling the content and common information including an access determination area for the content by a first encryption method, a work key for encrypting the common information, and contract information of the terminal device And information obtained by encrypting the individual information including the information according to the first encryption method, and multiplexing the information and sending the multiplexed information as a first stream to the first transmission path. The first stream received from the first transmission path is encrypted by a second encryption method, and transmitted to the second transmission path as a second stream together with decryption information on the second encryption method. The terminal device, after decrypting the second stream received from the second transmission path using the decryption information related to the second encryption method using the second encryption method, A conditional access system, wherein the content is decrypted by one encryption method, and access control to the content is performed based on an access determination area included in the common information and contract information included in the individual information. 2. A center device connected to a first transmission line, one or more relay devices connected to the first transmission line and a second transmission line, and a connection to the second transmission line A limited reception system for performing limited reception of digital broadcasting, comprising: at least one terminal device, wherein the center device includes: a scrambled content including at least one of video, audio, data, and a program; Information obtained by encrypting a scramble key for scrambling the content and common information including an access determination area for the content by a first encryption method, a work key for encrypting the common information, and contract information of the terminal device And information obtained by encrypting the individual information including the information according to the first encryption method, and multiplexing the information and sending the multiplexed information as a first stream to the first transmission path. The first stream received from the first transmission line is encrypted by a second encryption method, and sent out to the second transmission line as a second stream. The second stream received from the channel is decrypted by the second encryption method defined in advance, and then decrypted by the first encryption method, and the access determination area included in the common information and the individual A conditional access system for controlling access to the content based on contract information included in the information. 3. The relay device further encrypts the individual information of the first stream, which has been encrypted by the first encryption method, by the second encryption method. The terminal device sends the individual information out of the second stream using the second encryption method, and then decrypts the individual information using the first encryption method. The conditional access system according to claim 1, wherein the conditional access system performs the conversion. 4. The relay device further encrypts the common information of the first stream encrypted by the first encryption method by the second encryption method, and further encrypts the common information by the second encryption method. And the terminal device decodes the common information in the second stream using the second encryption method, and then uses the first encryption method. 3. The conditional access system according to claim 1, wherein decoding is performed. 5. The relay device encrypts the program arrangement information of the content in the first stream using the second encryption method, and sends the encrypted program arrangement information to the second transmission path as the second stream. The terminal device, after decoding the program sequence information in the second stream using the second encryption method,
3. The conditional access system according to claim 1, wherein the decryption is performed by the first encryption method. 6. The relay device has a function of adding frame packet information for multiplexing a plurality of transport streams to one transmission band, and encrypts the frame packet information by the second encryption method. And transmits the second stream as the second stream to the second transmission path. In the terminal device, after decoding the frame packet information in the second stream using a second encryption method, the 3. The conditional access system according to claim 1, wherein decryption is performed by one encryption method. 7. The relay device encrypts all signals including contents in the first stream by the second encryption method, and performs the second transmission as the second stream. And the terminal device decrypts all information including the content in the second stream using the second encryption method, and then decrypts the information using the first encryption method. 3. The conditional access system according to claim 1, wherein: 8. The relay device has two or more encryption methods, encrypts the individual information in the first stream using a different encryption method for each transport stream, and The terminal device sends the individual information out of the second stream using an encryption method for each of the transport streams, and then sends the first information to the first stream. 3. The conditional access system according to claim 1, wherein the encryption system is decrypted. 9. The relay device has two or more encryption methods, encrypts the common information in the first stream using a different encryption method for each transport stream, and After transmitting the common information in the second stream using the encryption method for each transport stream, the terminal device transmits the first stream to the second transmission path as the second stream. 3. The conditional access system according to claim 1, wherein the encryption system is decrypted. 10. The relay apparatus transmits the decryption information corresponding to the second encryption method as the second stream to the second transmission path using a frequency band different from that of the content. The conditional access system according to claim 1, wherein: 11. The relay device transmits the decryption information corresponding to the second encryption method as the second stream to the second transmission path using the same frequency band as the content. The conditional access system according to claim 1, wherein: 12. The relay device according to claim 1, wherein the relay device includes decryption information corresponding to the second encryption in the information of the frame packet and transmits the information as the second stream to the second transmission path. The conditional access system according to claim 1, wherein: 13. The terminal device has a first conditional access module for the first encryption scheme and a second conditional access module for the second encryption scheme, and the second transmission Said second stream received over the road,
The conditional access system according to claim 1, wherein after decoding is performed by the second conditional access module, decoding is performed by the first conditional access module. 14. A program for executing, by a computer, all or a part of the functions of all or a part of the center apparatus, relay apparatus, and terminal apparatus of the conditional access system according to claim 1. A program recording medium on which data is recorded, wherein the program recording medium is readable by a computer.