WO2014121652A1

WO2014121652A1 - Digital television signal receiving system and receiving method

Info

Publication number: WO2014121652A1
Application number: PCT/CN2014/000086
Authority: WO
Inventors: 陶圣华
Original assignee: 山东泰信电子股份有限公司
Priority date: 2013-02-08
Filing date: 2014-01-23
Publication date: 2014-08-14
Also published as: CN103581751A; CN103581751B

Abstract

Disclosed are a digital television signal receiving system and receiving method, comprising: a terminal entering an operating state; receiving an entitlement management message; the terminal reading a program list therein; a user selecting a program to be watched; the terminal sending to a gateway device a command for locking the selected program; the gateway device acquiring an SI table and an entitlement control message relevant to the selected program from a radio frequency signal of the radio and television network and sending same to the terminal; the terminal parsing the received SI table, entitlement control message and entitlement management message to obtain secret data relevant to descrambling the selected program; sending to the gateway device the secret data relevant to descrambling the selected program; the gateway device decrypting the received secret data to obtain a key used to descramble the selected program; descrambling the selected program using the key to obtain a program clear stream; sending the program clear stream to the terminal; and the terminal receiving the program clear stream, and decoding and playing same. The present invention solves the problem that digital television programs cannot be watched via a computer, a mobile phone, a tablet computer and other devices.

Description

Digital television signal receiving system and receiving method

The present invention relates to the field of digital television, and in particular, to a digital television signal receiving system and a receiving method.

Background technique

With the rapid development of network technology and chip technology, devices such as televisions, computers, mobile phones, and tablets all have network functions, and all of them can decode and play video and audio programs. Televisions, computers, mobile phones, and tablets have become people's eyes. The main means of audio programming. Digital TV programs are one of the most popular video and audio content. However, due to the special scrambling system of digital TV systems, only chips that support the digital TV standard can descramble the digital TV programs. Therefore, only digital TV integrated devices or set-top boxes In order to receive digital TV programs, computer chips, mobile phone chips and tablet chips that do not support digital TV standards cannot directly watch digital TV programs. In addition, with the continuous upgrading of digital TV technology and chip technology, the old digital TV chips produced before may not be able to watch digital TV programs because they cannot meet the requirements of the new digital TV encryption and decryption technology.

Summary of the invention

The purpose of the invention is to solve the problem that the current computer, mobile phone, tablet computer and the like cannot watch the digital television content because the main chip does not support the digital television standard, and the old digital television chip does not meet the requirements of the new digital television encryption and decryption technology. Unable to watch digital TV programs and other issues, and proposed a digital television signal receiving system and receiving method, which enables computers, mobile phones, tablet computers, and television sets using old digital television chips without modifying the hardware structure. Receive digital TV programs.

In order to achieve the above object, the present invention adopts the following technical solutions:

A digital television signal receiving method, comprising:

S1: The terminal enters a working state;

S2: the terminal receives the authorization management information EMM;

S3: The terminal acquires a program list in itself;

S4: The user selects a program to be watched on the terminal;

S5: the terminal sends a lock to the selected program command to the gateway device;

S6: the gateway device acquires an SI table and an authorization control information ECM related to the selected program from the radio frequency signal of the broadcasting network to the terminal;

S7: The terminal parses the received SI table, the authorization control information ECM, and the authorization management information EMM, and obtains secret data related to descrambling the selected program; S8: the terminal sends secret data related to descrambling the selected program to the gateway device;

S9: the gateway device decrypts the received secret data, and obtains a key CW used to descramble the selected program;

S10: The gateway device uses the key CW to descramble the selected program to obtain program clearing;

S11: The gateway device sends the program clear stream to the terminal.

S12: The terminal receives the program clear stream, decodes and plays the program.

Before the step S2, the conditional receiving front end performs handshake communication with the terminal and the gateway device to confirm the legality of the terminal and the gateway device.

The steps of the handshake communication are:

1) the conditional receiving front end sends the handshake data to the terminal through the IP network;

2) The terminal parses the handshake data to obtain an encrypted form of the key and an encrypted form of the verification data;

3) the terminal sends the encrypted form key and the encrypted form of the verification data to the gateway device;

4) The gateway device decrypts the encrypted form of the key and the encrypted form of the verification data to obtain the verification data in a decrypted form;

5) the gateway device sends the decrypted verification data to the terminal;

6) the terminal sends the received verification data to the conditional receiving front end;

7) The conditional receiving front end judges the legitimacy of the terminal and the gateway device according to the received verification data.

Further, the step of the handshake communication is:

(1) The conditional receiving front end sends the handshake data to the gateway device through the IP network;

(2) the gateway device sends the received handshake data to the terminal through the IP network;

(3) The terminal parses the handshake data to obtain an encrypted form of the key and an encrypted form of the verification data;

(4) The terminal sends the encrypted form of the key and the encrypted form of the verification data to the gateway device;

(5) the gateway device decrypts the encrypted form of the key and the encrypted form of the verification data to obtain the verification data in a decrypted form;

(6) the gateway device sends the decrypted verification data to the conditional receiving front end;

(7) The conditional receiving front end judges the legitimacy of the terminal and the gateway device based on the received verification data.

The step S2 is specifically: the terminal receives the authorization management information EMM sent by the front end through the IP network; or the terminal receives the authorization management information EMM obtained by the gateway device from the radio frequency signal; or the terminal receives the gateway device from the IP network. The conditionally receives the authorization management information EMM obtained by the front end.

The step S3 further includes

a) the terminal determines whether there is a program list in itself, if yes, performs step b); if not, performs step c); b) the terminal reads its own program information data and parses;

c) the terminal sends a lock primary frequency point command to the gateway device; d) the gateway device locks the primary frequency point, obtains the NIT table from the radio frequency signal, and sends it to the terminal;

e) the terminal parses the NIT table to obtain frequency point information in the radio frequency signal;

f) the terminal sends a lock frequency command to the gateway device;

g) the gateway device locks the corresponding frequency point according to the received command, and returns the PAT, PMT, SDT table of the current locking frequency point to the terminal;

h) the terminal parses the PAT, PMT, and SDT tables to obtain program information of the currently locked frequency point;

i) the terminal determines whether all frequency points in the radio frequency signal have performed a locking operation, and if so, performing step j) _; if not, performing step f);

j) Save the acquired program information to the memory of the terminal.

The step S11 is further: the gateway device uses the public key of the terminal to encrypt the program clear stream, and sends the encrypted program clear stream to the terminal;

The step S12 is further: the terminal receives the encrypted program clear stream, decrypts the encrypted program clear stream by using the private key of the terminal, and decodes and plays the decrypted program clear stream.

The terminal public key is sent by the terminal to the gateway device when the terminal establishes a connection with the gateway device; the data encrypted by using the terminal public key can be decrypted using the private key of the terminal.

When the terminal performs the above work, the terminal periodically performs the step S2.

The SI table includes at least one of a PAT, PMT, SDT, and CAT table.

A digital television signal receiving system comprising at least one gateway device, at least one terminal and at least one conditional receiving front end; wherein

The gateway device includes at least a tuning demodulation module, a demultiplexing module, a decryption module, a descrambling module, a processing unit, and a network module. The gateway device and the at least one terminal are bidirectionally connected through the IP network, and the gateway device receives the command sent by the terminal. Receiving a radio frequency signal from the broadcasting network, performing tuning, demodulating and demultiplexing the radio frequency signal to obtain a program transmission stream TS, an authorization information including at least the authorization control information ECM, and service information S1, and the gateway device sends the authorization information and the SI information to the terminal, where After receiving the secret data related to the descrambling program sent by the terminal, decrypting the secret data to obtain the key CW of the descrambled program, decrypting the program transmission stream TS by using the key CW, and transmitting the descrambled program stream to the terminal;

The terminal sends a command to the gateway device to control the gateway device to work, parses the SI table sent by the gateway device, parses the authorization control information ECM and the authorization management information EMM to obtain secret data related to descrambling the current program, and sends the secret data to the gateway. The device performs a decryption and descrambling operation; the terminal further receives a program stream sent by the gateway device, and decodes and plays the program;

The conditional receiving front end and the at least one terminal are bidirectionally connected through the IP network, and the conditional receiving front end generates authorization control information. The ECM is sent to the public network, and the authorization management information EMM is generated and sent to the terminal through the broadband network or the IP network. The conditional receiving front end also performs handshake communication with the terminal and the gateway device to verify the legality of the terminal and the gateway device.

The gateway device includes at least a tuning demodulation module, a demultiplexing module, a decryption module, a descrambling module, a processing unit, and a network module. The gateway device and the at least one terminal are bidirectionally connected through the IP network, and the gateway device receives the command sent by the terminal. Receiving a radio frequency signal from the broadcasting network, and performing tuning, demodulation, and demultiplexing of the radio frequency signal to obtain a program transmission stream TS, an authorization information including at least the authorization control information ECM, and service information S1, and the gateway device sends the authorization information and the SI information to the terminal, where After receiving the secret data related to the descrambling program sent by the terminal, decrypting the secret data to obtain the key CW of the descrambled program, decrypting the program transmission stream TS by using the key CW, and transmitting the descrambled program stream to the terminal;

The terminal sends a command to the gateway device to control the gateway device to work, parses the SI table sent by the gateway device, parses the authorization control information ECM and the authorization management information EMM to obtain secret data related to descrambling the current program, and sends the secret data to the gateway. The device performs a decryption and descrambling operation; the terminal further receives a program stream sent by the gateway device, and decodes and plays the node@;

The conditional receiving front end and the at least one gateway device are bidirectionally connected through the IP network, and the conditional receiving front end generates the authorization control information ECM and sends it to the broadcasting network, generates the authorization management information EMM, and sends the authorization management information to the gateway device and then sends the information to the terminal through the broadband network or the IP network. The conditional receiving front end also performs handshake communication with the terminal and the gateway device to verify the legality of the terminal and the gateway device.

The gateway device also includes a key generation module for generating a key for decrypting the secret data and a key for generating a key in an encrypted form in the decrypted handshake data.

The gateway device further includes an encryption module, configured to encrypt the program clear stream obtained after the descrambling.

The terminal is at least one of a television, a computer, a mobile phone, and a tablet.

The invention has the beneficial effects that: the invention receives the digital television signal from the wide-area network through the gateway device, and locks the program to be watched according to the command of the terminal, decrypts the authorization information, obtains the key CW for descrambling the program, and uses the key The CW descrambles the program transmission stream, and then sends the descrambled program transmission stream to the terminal for decoding and playing, and solves the problem that the computer, the mobile phone, the tablet computer that does not support the digital television standard, and the old digital number that does not meet the requirements of the new digital television technology are solved. The device such as a television chip of a television chip cannot watch the digital television program without changing the hardware, and the implementation is simple and convenient, and the cost is low; and the gateway device of the present invention is only responsible for transmitting the descrambled program stream to the terminal, and the terminal performs decoding. And playing, can effectively reduce the amount of data transmitted between the gateway device and the terminal, and reduce the bandwidth occupied by the data transmission. In addition, the present invention also uses the conditional receiving front end to verify the legality of the terminal and the gateway device, and ensures that only legitimate terminals and gateway devices are ensured. In order to watch digital TV programs, the interests of operators are guaranteed and the security is high. It can be seen that the invention has the advantages of simple and convenient implementation, less network bandwidth occupation, high security and the like.

DRAWINGS

Figure 1 is a schematic structural view of the system of the present invention;

Figure 2 is a schematic view showing another structure of the system of the present invention;

3 is a schematic structural diagram of a gateway device in the system of the present invention;

4 is a flow chart of Embodiment 1 of the method of the present invention;

Figure 5 is a flow chart of Embodiment 2 of the method of the present invention;

6 is a flow chart of handshake communication between the conditional receiving front end and the terminal and the gateway device according to the present invention;

7 is another flow chart of handshake communication between the conditional receiving front end and the terminal and the gateway device according to the present invention;

8 is a flowchart of a program list in a terminal acquiring terminal according to the present invention;

Figure 9 is a flow chart of Embodiment 3 of the method of the present invention.

detailed description

The invention will be further described below in conjunction with the drawings and embodiments.

The drawings are intended to provide a further understanding of the invention, and are intended to be illustrative of the invention.

As shown in FIG. 1, a digital television signal receiving system includes at least one gateway device, at least one terminal, and at least one conditional receiving front end;

The gateway device includes at least a tuning demodulation module, a demultiplexing module, a decryption module, and a descrambling module. The gateway device and the at least one terminal are bidirectionally connected through the IP network, and the gateway device receives the command sent by the terminal, and receives the radio frequency signal from the broadband network. The radio frequency signal is tuned and demultiplexed and demultiplexed to obtain a program transmission stream TS, an authorization information including at least the authorization control information ECM, and service information S1. The gateway device sends the authorization information and the SI information to the terminal, and receives the After descrambling the secret data related to the program, decrypting the secret data to obtain the key CW of the descrambled program, decrypting the program transmission stream TS by using the key CW, and transmitting the descrambled program stream to the terminal;

The conditional receiving front end is bidirectionally connected to the at least one terminal, and the conditional receiving front end generates the authorization control information ECM and sends it to the wide network, generates the authorization management information EMM, and sends the authorization management information to the terminal through the wide network or the IP network; It also performs handshake communication with the terminal and the gateway device to verify the legality of the terminal and the gateway device.

The terminal is a television, a computer, a mobile phone or a tablet.

As shown in FIG. 2, a digital television signal receiving system includes at least one gateway device, at least one terminal, and at least one conditional receiving front end; wherein

As shown in FIG. 3, the gateway device includes a tuner demodulation module, a demultiplexing module, a descrambling module, a key generation module, a decryption module, a processing unit, and a network module, where

The tuned demodulation module and the demultiplexing module are unidirectionally connected, receive the radio frequency digital television signal, and are tuned and demodulated and sent to the demultiplexing module;

The demultiplexing module is connected to the descrambling module, and the demultiplexing module demultiplexes the demodulated digital television signal, sends the authorization information and the service information SI to the terminal, and sends the program transmission stream to the descrambling module;

The descrambling module is connected to the decryption module, receives the key CW of the descrambled program sent by the decryption module, and outputs the descrambled program stream to the terminal;

The descrambling module is connected to the key generation module, receives the key required to descramble the secret data generated by the key generation module, receives the secret data sent by the terminal, and decrypts the secret data by using the received key to obtain a solution. The key CW required to disturb the program.

The processing unit passes the bus and the tuner demodulation module, the demultiplexing module, the descrambling module, the key generation module, and the decryption The module and the encryption module are connected in two directions, and the information of each module is obtained and the modules are configured.

The network module is respectively connected to the demultiplexing module, the descrambling module, the decryption module, and the encryption module, and is used to implement data communication between the gateway device and the terminal device.

The gateway device further includes an encryption module, and the encryption module is connected to the descrambling module, encrypts program data sent by the descrambling module, and sends the encrypted program data to the terminal.

Example 1:

As shown in FIG. 4, the digital television signal receiving method has the following steps:

S101: The terminal enters a working state;

S102: The conditional receiving front end performs handshake communication with the terminal, and confirms the legality of the terminal;

S103: The terminal receives the conditional authorization management information EMM sent by the front end;

S104: The terminal reads the program list in itself;

5105: The user selects a program to watch on the terminal;

S106: The terminal sends a lock to the selected program command to the gateway device.

S107: The gateway device acquires, from the radio frequency signal of the wide-area network, the SI table and the authorization control information ECM related to the selected program to the terminal;

S108: The terminal parses the received SI table, the authorization control information ECM, and the authorization management information EMM, and obtains secret data related to descrambling the selected program;

S109: The terminal sends secret data related to descrambling the selected program to the gateway device;

S110: The gateway device decrypts the received secret data, and obtains a key CW used to descramble the selected program;

S111: The gateway device uses the key CW to descramble the selected program to obtain program clearing;

S112: The gateway device sends the program clear stream to the terminal.

S113: The terminal receives the program clear stream, decodes and plays the program.

Example 2:

As shown in FIG. 5, the digital television signal receiving method has the following steps: - S201: the terminal enters a working state;

S202: The conditional receiving front end performs handshake communication with the terminal, and confirms the legality of the terminal;

S203: The gateway device obtains the authorization management information EMM from the radio frequency signal of the public network and sends the information to the terminal.

S204: The terminal reads the program list in itself;

S205: The user selects a program to be watched on the terminal;

S206: The terminal sends a lock to the selected program command to the gateway device. S207: The gateway device acquires an SI table and an authorization control information ECM related to the selected program from the radio frequency signal of the broadcasting network to the terminal;

S208: The terminal parses the received SI table, the authorization control information ECM, and the authorization management information EMM, and obtains secret data related to descrambling the selected program;

S209: The terminal sends secret data related to descrambling the selected program to the gateway device;

S210: The gateway device decrypts the received secret data, and obtains a key CW used to descramble the selected program;

S211: The gateway device uses the key CW to descramble the selected program to obtain program clearing;

S212: The gateway device encrypts the program clear stream by using the public key of the terminal, and sends the encrypted program data to the terminal;

S213: The terminal receives the encrypted program data, decrypts the encrypted program data by using the terminal private key, and decodes and plays the decrypted program data.

As shown in FIG. 6, the conditional receiving front end performs a handshake communication process with the terminal and the gateway device, and the steps are as follows:

2) The terminal parses the handshake data to obtain the encrypted key EKey and the encrypted form verification data NONCE;

3) The terminal sends the encrypted key EKey and the encrypted form authentication data NONCE to the gateway device;

4) The gateway device decrypts the encrypted key EKey to obtain the key Key;

5) The gateway device uses the Key as the original key to decrypt the encrypted verification data NONCE, and obtains the decrypted verification data;

6) the gateway device sends the decrypted verification data to the terminal;

7) the terminal sends the received verification data to the conditional receiving front end;

8) The conditional receiving front end determines whether the received verification data is the same as the expected data. If they are the same, the terminal and the gateway device are legal; otherwise, the terminal and the gateway device are invalid.

As shown in FIG. 7, the conditional receiving front end performs a handshake communication process with the terminal and the gateway device, and the steps are as follows:

(5) the gateway device decrypts the encrypted form of the key and the encrypted form of the verification data to obtain the verification data in a decrypted form; (6) the gateway device sends the decrypted verification data to the conditional receiving front end;

(7) The conditional receiving front end judges the legitimacy of the terminal and the gateway device according to the received verification data. If the verification data is the same as the expected data, the terminal and the gateway device are legal; otherwise, the terminal and the gateway device are invalid.

As shown in Figure 8, the terminal obtains the flow of the program list in itself, and its steps are as follows:

a) the terminal determines whether there is a program list in itself, if yes, performs step b); if not, performs step c) _; b) the terminal reads its own program information data and parses;

c) the terminal sends a lock primary frequency point command to the gateway device;

d) the gateway device locks the primary frequency point, obtains the NIT table from the radio frequency signal, and sends it to the terminal;

f) the terminal sends a lock frequency command to the gateway device;

i) the terminal determines whether all frequency points in the radio frequency signal have performed a locking operation, and if so, performing step j); if not, executing step 0;

j) Save the acquired program information to the memory of the terminal.

Example 3:

As shown in FIG. 9, the digital television signal receiving method has the following steps:

S301: The terminal enters a working state;

S302: The conditional receiving front end performs handshake communication with the terminal, and confirms the legality of the terminal.

S303: The gateway device obtains the authorization management information EMM from the radio frequency signal of the public network and sends the information to the terminal.

S304: The terminal reads the program list in itself;

S305: The user selects a program to be watched on the terminal;

S306: The terminal parses the program selected by the user, and obtains program information that includes at least a frequency point of the program, program video stream information, and program audio stream information.

S307: The terminal sends a lock frequency command to the gateway device.

S308: The gateway device performs a lock frequency operation, and returns a frequency point lock status to the terminal.

S309: The terminal determines the frequency point lock state. If the lock is successful, step S310 is performed; if the lock fails, the lock frequency point failure prompt is given;

S310: The terminal sends a configuration PID filter and a Section filter command to the gateway device. S311: The gateway device sets the PID filter and the section fi lter, obtains the CAT and the EMM, and returns to the terminal; S312: the terminal parses the E匪 to obtain the terminal authorization information, if the current program is not authorized, gives a prompt, waits for the user to operate; if the current program has Authorization, step 313;

S313: The terminal sends a configuration PID fi lter and a Section filter command to the gateway device.

S314: The gateway device sets the PID filter and the Section fi lter, obtains the PMT, and sends the PMT to the terminal;

S315: The terminal parses the PMT, determines whether the current program is a scrambled stream or a clear stream, if it is a clear stream, step S316 is performed; if it is a scrambled stream, step S319 is performed;

S316: The terminal sends a configuration PID fi lter command to the gateway device.

S317: The gateway device configures a PID filter, and sends the program stream to the terminal device.

S318: The terminal device receives the program stream, decodes and plays;

S319: The terminal sends a configuration PID filter and a Section fi lter command to the gateway device;

S320: The gateway device configures a PID filter and a section fi lter, obtains an authorization control information ECM from the radio frequency signal, and sends the ECM information to the terminal;

S321: The terminal parses the ECM information, and obtains the encrypted key CW data and sends the key CW data to the gateway device.

S322: The terminal sends the key data related to the key CW obtained by decrypting the encrypted form obtained by the EMM to the gateway device;

S323: The gateway device decrypts the key data to obtain a key of the key CW in a decrypted encrypted form, and uses the key to decrypt the encrypted key CW to obtain a key CW of the descrambled program;

S324: The gateway device uses the key CW to descramble the program data, and sends the descrambled program data to the terminal.

S325: The terminal receives the program data, decodes and plays the program.

The above is a preferred embodiment of the present invention, and various modifications or variations made on the basis of the technical solutions of the present invention are still within the scope of the present invention.

Claims

Claim

A digital television signal receiving method, characterized in that it comprises:

S1: The terminal enters a working state;

S2: the terminal receives the authorization management information EMM;

S3: The terminal reads a list of programs in itself;

S4: The user selects a program to be watched on the terminal;

S7: The terminal parses the received SI table, the authorization control information ECM, and the authorization management information EMM to obtain secret data related to descrambling the selected program;

S8: the terminal sends secret data related to descrambling the selected program to the gateway device;

S11: The gateway device sends the program clear stream to the terminal.

The digital television signal receiving method according to claim 1, wherein before the step S2, the conditional receiving front end performs handshake communication with the terminal and the gateway device to confirm the legality of the terminal and the gateway device.

3. The digital television signal receiving method according to claim 2, wherein the step of the handshake communication is:

2) The terminal parses the handshake data to obtain a key in an encrypted form and verification data in an encrypted form;

5) the gateway device sends the decrypted verification data to the terminal;

4. The digital television signal receiving method according to claim 2, wherein the step of the handshake communication is:

1) The conditional receiving front end sends the handshake data to the gateway device through the IP network;

2) The gateway device sends the received handshake data to the terminal through the IP network;

3) The terminal parses the handshake data to obtain an encrypted form of the key and an encrypted form of the verification data;

4) The terminal sends the encrypted form key and the encrypted form of the verification data to the gateway device; 5) The gateway device decrypts the encrypted form of the key and the encrypted form of the verification data to obtain the verification data in a decrypted form;

6) The gateway device sends the decrypted verification data to the conditional receiving front end;

The method for receiving a digital television signal according to claim 1, wherein the step S2 is specifically: the terminal receives the authorization management information EMM sent by the front end through the IP network; or the terminal receives the RF signal from the gateway device. Obtaining the concurrent authorization management information EMM; or the terminal receiving the authorization management information EMM obtained by the gateway device from the conditional access front end through the IP network.

The digital television signal receiving method according to claim 1, wherein the step S3 further comprises: a) the terminal determining whether there is a program list in itself, if yes, performing step b); if not, performing Step c); b) the terminal reads its own program information data and parses;

f) the terminal sends a lock frequency command to the gateway device;

«) The terminal judges whether all the frequency points in the RF signal have performed the locking operation, and if so, performs step j); if not, performs step f);

j) Save the acquired program information to the memory of the terminal.

The digital television signal receiving method according to claim 1, wherein the step S11 is further: the gateway device uses the public key of the terminal to encrypt the program clear stream, and sends the encrypted program clear stream to the terminal;

The digital television signal receiving method according to claim 7, wherein the terminal public key is sent by the terminal to the gateway device when the terminal establishes a connection with the gateway device; and is encrypted by using the terminal public key. The data can be decrypted using the private key of the terminal.

9. The digital television signal receiving method according to claim 1, wherein the terminal periodically performs the step S2 during the execution of the method by the terminal.

10. The digital television signal receiving method according to claim 1, wherein said SI table includes at least PAT, One of the PMT, SDT, and CAT tables.

A digital television signal receiving system, comprising: at least one gateway device, at least one terminal, and at least one conditional receiving front end; wherein

The terminal sends a command to the gateway device to control the gateway device to work, parses the SI table sent by the gateway device, parses the authorization control information ECM and the authorization management information EMM to obtain secret data related to descrambling the current program, and sends the secret data to the gateway. The device performs decryption and descrambling operations; the terminal further receives a program stream sent by the gateway device, and decodes and plays the node §;

The conditional receiving front end and the at least one terminal are bidirectionally connected through the IP network, and the conditional receiving front end generates the authorization control information ECM and sends it to the wide power grid to generate the authorization management information EMM and sends it to the terminal through the broadband network or the IP network; It also performs handshake communication with the terminal and the gateway device to verify the legality of the terminal and the gateway device.

The conditional receiving front end and the at least one gateway device are bidirectionally connected through the IP network, and the conditional receiving front end generates the authorization control information ECM and sends it to the wide power grid to generate the authorization management information EMM and sends it to the gateway device through the wide power grid or the IP network. And sending to the terminal; the conditional receiving front end also performs handshake communication with the terminal and the gateway device, and verifies the legality of the terminal and the gateway device.

The digital television signal receiving system according to claim 11 or 12, wherein the gateway device further comprises a key generation module, configured to generate a key for decrypting the secret data and generate an encrypted form in the decrypted handshake data. The key of the key.

The digital television signal receiving system according to claim 11 or 12, wherein the gateway device further comprises an encryption module, configured to encrypt the program clear stream obtained after the descrambling.

The digital television signal receiving system according to claim 11 or 12, wherein the terminal is at least one of a television, a computer, a mobile phone, and a tablet.