JP2005079860A - Broadcast receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a restricted broadcast receiver which can simultaneously be applied to a second receiver and receivers following this without requiring any reform of an IC card which is already in service. <P>SOLUTION: A junction circuit 26 transmits first restricted received information inputted from a transmission and reception interface 25 or second restricted received information from another receiver inputted from a bridge terminal 27 to the IC card 14 through an IC card terminal 23. Then, the junction circuit 26 transmits a response corresponding to the first restricted received information from the IC card 14 to the interface 25, and transmits a response corresponding to the second restricted received information from the IC card 14 to another receiver through the bridge terminal 27. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a broadcast receiving apparatus.

  Currently, a limited reception broadcasting system is a system that allows only one receiver to receive data using one IC card with one reception contract, and enables simultaneous reception by a plurality of receivers. I can't. This is because the broadcasting station restricts because there is a fear of illegal reception. It is only considered that the receiving device and the IC card are used only in a one-to-one combination. Even if there are a plurality of receiving devices, a plurality of limited reception target programs and channels stored in one IC card are used. The contents of the viewing contract cannot be used by the second and subsequent receivers.

  In such a broadcasting system, an IC card is required for each receiving device, such as when viewing multiple channels at the same time or recording a back program, and the same viewing contract is duplicated by the number of IC cards. You have to conclude and pay multiple viewing fees.

  It can be said that such a situation is illegally infringed on a viewing contractor even though they have purchased the right to view a plurality of programs and channels.

  In order to solve this problem, for example, a plurality of IC cards are prepared in one contract as disclosed in Japanese Patent Application Laid-Open No. 10-178629, these IC cards themselves have a communication function, and the IC cards communicate directly with each other. We have proposed a broadcast system that prevents unauthorized reception by sharing contract information.

  Also, as disclosed in Japanese Patent Application Laid-Open No. 2002-64798, a plurality of IC cards are temporarily separated from the receiving device, and an arbitration function and an authentication function between the IC card and the receiving device are provided to communicate with each other. A method of trying to interact is disclosed.

  However, in Japanese Patent Laid-Open No. 10-178629, not only the modification of the receiving device but also at least one special IC card different from the current IC card is required. In addition, some of the embodiments of this method cannot be used together with a conventional IC card.

In addition, although the method disclosed in Japanese Patent Laid-Open No. 2002-64798 has an advantage that contracts between a plurality of IC cards can be accommodated, in the first place, there is only one viewing contract for each program or channel for one contractor or one household. In most cases, it is useless to use a plurality of IC cards.
Japanese Patent Laid-Open No. 10-178629 JP 2002-64798 A

  The present invention has been made to solve such a problem, does not require any modification of an IC card that is already in service, does not change the configuration of the main part of the receiving apparatus, and also receives an IC card and a plurality of receiving cards. New broadcast work between devices is not required, and limited broadcasts that can be applied to a plurality of conditional access target programs and channels assigned to one IC card at the same time on the second and subsequent receivers An object is to provide a receiving apparatus.

To achieve the above object, the present invention provides a descrambler that descrambles encrypted data;
A transmission / reception interface connected to the descrambler and transmitting / receiving to / from the outside;
An IC card terminal for communicating with an IC card that processes conditional access information;
A junction circuit connected between the transmission / reception interface and the IC card terminal and controlling a transmission / reception direction of the limited reception information;
A bridge terminal connected to the junction circuit for communicating the limited reception information with another receiving device;
The junction circuit receives the first limited reception information input from the transmission / reception interface or the second limited reception information from the other receiving device input from the bridge terminal via the IC card terminal. A response corresponding to the first limited reception information from the IC card is transmitted to the transmission / reception interface, and a response corresponding to the second limited reception information from the IC card is transmitted to the bridge terminal. There is provided a broadcast receiving apparatus, characterized in that control is performed so as to transmit to the other receiving apparatus.

  The limited reception information of the reception device transmitted from the transmission / reception interface of the reception device or the limited reception information of another reception device transmitted from the bridge terminal is transmitted to one IC card via the IC card terminal, The conditional access information is sent to the corresponding receiving device. In this way, viewing can be performed with a plurality of receiving apparatuses using one IC card. Since one IC card is originally used, there is no worry of illegal reception.

  FIG. 1 is a block diagram for explaining one embodiment of the apparatus of the present invention. Since encryption is performed with three types of keys, a master key (Km), a work key (Kw), and a scramble key (Ks), it is called a triple key method.

  As shown in FIG. 1, the broadcasting station 1 has contract information from the contract information recording means 2 storing contract information describing contract details of each contractor and a work in which a work key (Kw) is stored. The multiplexer 4 multiplexes the work key (Kw) from the key (Kw) storage means 3. This multiplexed one is encrypted by the encryption circuit 6 using the master key (Km) from the master key (Km) storage means 5 in which the master key (Km) is stored. In this way, contract information called EMM (Entitlement_Management_Message, individual information) is created. The EMM information is transmitted along with the content information scrambled by the scrambler 11 and transmitted to all receiving apparatuses on a broadcast wave.

  The broadcast station 1 also receives program information from the program information storage means 7 in which the program information describing the channel and the program to be broadcast is stored, and a scramble key (Ks) means 8 in which the scramble key (Ks) is stored. The scramble key (Ks) is multiplexed by the multiplexer 9 and encrypted by the encryption circuit 10 using the work key (Kw) from the work key (Kw) storage means 3. In this way, contract information called ECM (Entitlement_Control_Message, common information) is created.

  This ECM information is also broadcast by the multiplexer 12.

  The receiving device 13 separates the content of the broadcast signal broadcast from the broadcast station 1 by the separator 15 and descrambles it by the descrambler 22 so that the program can be viewed. Here, the IC card 14 actually processes the EMM information and ECM information used for the descrambler.

  The master key (Km) storage means 5 possessed by the broadcasting station 1 stores a different master key (Km) for each IC card 14 possessed by each contractor, which is transmitted to other contract receivers. The EMM cannot be interpreted, and the contract receiving apparatus can interpret only the EMM transmitted to itself.

  In the IC card 14, the EMM is decrypted by the encryption / decryption circuit 16 using its own master key (Km) stored in the master key (Km) storage unit 5 ′. As a result of analyzing the contents by the separator 17, only the EMM that has been correctly decrypted, that is, the EMM that has been delivered to the user, the decrypted contract information to the contract information storage means 2 ′ and the work key (Kw) Separately stored in the work key storage means (Kw) 3 ′.

  The master key (Km) stored in the master key (Km) storage unit 5 'in the IC card 14 is not updated. The transmission frequency of EMM, that is, the update frequency of contract information and work key (Kw) is from one month to several years. The same value is used for all IC cards 14 as the work key (Kw) itself.

  The IC card 14 used together with the receiving device 13 also transmits the broadcast wave to all the receiving devices and finally receives it. Further, the broadcast station 1 scrambles unscrambled content provided to the contractor, such as video / audio / service data, that is, the content by the scrambler 11 using the scramble key stored in the scramble key storage means 8 ′. Then, it is transmitted to all receivers on a broadcast wave.

  In the IC card 14, the ECM is decrypted by the encryption / decryption circuit 18 using the work key (Kw) possessed by itself, and the content is analyzed by the separator 19. For only the ECM, the decrypted program information and the scramble key (Ks) are separated and stored in the program information storage means 7 ′ and the scramble key storage means 8 ′, respectively. At this time, the contract information collating circuit 20 compares the contents of the contract information already acquired in the contract information storage means 2 ′ with the contents of the program information acquired now, and a contract for viewing this program is concluded. If it can be confirmed, the switch 21 is closed and the scramble key (Ks) just acquired is given from the IC card 14 to the descrambler 22 of the receiving device 13.

  The descrambler 22 de-scrambles the scrambled content obtained from the separator 15 using the scramble key (Ks) provided / updated by the IC card 14, and finally obtains the unscrambled content.

  If the conclusion of the contract for viewing the program cannot be confirmed, the switch 21 is opened so that the scramble key (Ks) is not output from the IC card, and as a result, the descrambler 22 releases the scramble applied to the scrambled content. I can't do that.

The information stored in the program information storage means 7 ′ includes information on the channel on which the program is broadcast, and the update frequency is usually for each program. Since the scramble key (Ks) storage means 8 'needs to be changed frequently for countermeasures against decryption, the update frequency is normally set to about 1 second. The same value is used for the scramble key (Ks) with respect to the scrambler 22 of all receiving apparatuses 13, and among the three keys, Km, Kw, and Ks, the only unencrypted value is provided outside the IC card 14. appear.

  FIG. 2 is a schematic block diagram of the receiving apparatus of the present invention. In FIG. 1, the EMM, the ECM, and the scrambled key (Ks) that has been decrypted are depicted as separate signal paths between the receiving device 13 and the IC card 14, but actually, as shown in FIG. These three signals are exchanged together through the IC card terminal 23 as a single bidirectional communication path. When the EMM or ECM is inputted from the separator 15, the controller 24 gives it to the transmission / reception interface 25 in order to transmit it to the IC card 14. The transmission / reception interface 25 receives this, converts the EMM or ECM into a communication signal with the IC card 14, and transmits it to the IC card 14 via the IC card terminal 23.

  The IC card 14 outputs the encrypted / decrypted scramble key (Ks) to the transmission / reception interface 25 via the IC card terminal 23. The transmission / reception interface 25 receives this and outputs it to the controller 24 after signal conversion. The controller 24 sets the scramble key (Ks) after signal conversion and encryption / decryption in the descrambler 22. By the way, the signal sent via the IC card terminal 23 is standardized by JIS X 6304-1996, and its specifications are open to the public.

  In general, the contract information stored in the IC card 14 describes the contents of viewing contracts for a plurality of programs and channels. Thus, even when switching between a plurality of limited reception target programs and channels for viewing, one sheet The IC card 14 is sufficient.

  In the receiving device 13, a junction circuit 26 is connected between the IC card terminal 23 and the transmission / reception interface 25. A signal path is connected to the junction circuit 26 via the bridge terminal 27 from the junction circuit 26 to the outside of the housing of the receiving device 13.

  FIG. 3 shows an example in which two receivers 30 and 40 are connected via a bridge terminal 37 and a bridge terminal 47. At this time, the IC card 14 is attached to the receiving device 30. No IC card is attached to the second receiver 40. The first receiver 30 and the second receiver 40 are connected via a bridge terminal 37 of the first receiver and a bridge terminal 47 of the second receiver.

  FIG. 4 is a flowchart showing the operation of the junction circuit 26.

  Step_0 is a standby state. In this state, when an EMM or ECM is received from the transmission / reception interface 25 or the bridge terminal 27, it is first confirmed whether the transmission is from the transmission / reception interface 25 or the bridge terminal 27 (Step_2). If it is from the transmission / reception interface 25, the process proceeds to Step_3, and if it is from the bridge terminal 27, the process proceeds to Step_15.

  In Step — 3, it is confirmed whether or not the IC card 14 is attached to the IC card terminal 23 connected to the junction circuit 26. If it is attached, go to Step_4. If not, go to Step_11.

  At Step_4, it is confirmed whether or not the junction circuit 26 has already performed transmission for which a response is expected and is waiting for the response. If it is waiting for a response, it waits until the response waiting is canceled in Step_5, and if not, it proceeds to Step_6.

  In Step_6, it is confirmed whether the junction circuit 26 has received the EMM or the ECM. If it is an EMM, the EMM is transmitted to the IC card 14 (Step_10), and the state returns to the Start standby state (Step_0). . If it is ECM, it is transmitted to the IC card 14 and the response waiting state is entered (Step_7).

  In the response waiting state, another EMM or ECM is not newly transmitted to the IC card 14 until a response from the IC card 14 returns. That is, the IC card 14 always processes only one EMM or ECM at a time, and does not perform parallel processing. When the response from the IC card 14 is received (Step_8), the junction circuit 26 transmits the response to the transmission / reception interface 25 (Step_9), and returns to the Start standby state (Step_0).

  In Step_3, if the IC card 14 is not attached to the IC card terminal 23 connected to the junction circuit 26, the bridge is transferred to the IC card 14 attached to another receiving device. Transmit via terminal 27. Before that, at Step_11, it is confirmed whether the received EMM or ECM. If it is an EMM, it is considered that it has already been transmitted by another receiving apparatus having the IC card 14 mounted thereon, so that it is discarded and returns to the Start standby state (Step_0).

  If it is the ECM received at Step_11, the ECM is transmitted to the bridge terminal 27 and a response wait state is entered (Step_12). In this state, no EMM or ECM is newly transmitted to the bridge terminal 27 or the IC card terminal 23. When receiving a response from the bridge terminal 27 (Step_13), the junction circuit 26 transmits the response to the transmission / reception interface 25 (Step_14), and returns to the Start standby state (Step_0).

  In Step_2, when the transmission source is the bridge terminal 27, the process proceeds to Step_15, and it is confirmed whether or not the IC card 14 is attached to the IC card terminal 23 connected to the junction circuit 26 concerned. If it is not attached, the received EMM or ECM or IC card 14 to be processed does not exist in either the transmission device receiving device or the receiving device having the junction circuit 26. Then, it is discarded and the process returns to the Start standby state (Step_0). If the IC card 14 is mounted, the process proceeds to Step_16.

  In Step_16, it is confirmed whether or not the junction circuit 26 has already performed transmission for which a response is expected and is waiting for the response. If it is waiting for a response, it waits until the response waiting is canceled at Step_17, and if not, it proceeds to Step_18.

  In Step_18, it is confirmed whether the junction circuit 26 has received the EMM or the ECM. If it is an EMM, it is considered that the junction circuit 26 has already transmitted, so it is discarded and the Start is started. Return to the standby state (Step_0). If it is ECM, it is transmitted to the IC card 14, and the response waiting state is entered (Step_19).

  In the response waiting state, another EMM or ECM is not newly transmitted to the IC card 14 until a response from the IC card 14 returns. Again, the IC card 14 always processes only one EMM or ECM, and does not perform parallel processing. When receiving the response from the IC card 14 (Step_20), the junction circuit 26 transmits the response to the bridge terminal 27 (Step_21), and returns to the Start standby state (Step_0).

  Actually, an incremental ID number is assigned to the communication between the IC card 14 and the transmission / reception interface 25 of the receiving device 28 every time a lump of signals is transmitted. Therefore, when the junction circuit 26 outputs a signal to the IC card terminal 23 (Step_7, Step_10, Step_12, Step_19), the ID number is once reassigned so that the number becomes incremental, and the IC card When a response is received from the transmission / reception interface 25 or the bridge terminal 27 (Step_9, Step_14, Step_21), the reassigned ID number is returned to the original ID number according to each response signal. A function is required.

In the present invention, since a plurality of signals are not transmitted / received in parallel, the function is a simple logic circuit, which is greatly simplified as compared with a circuit for performing authentication between each IC card and a receiving device. it can.

  In the apparatus configuration shown in FIG. 3, Step_0 → Step_1 → Step_2 → Step_3 → Step_4 → (Step_5 →) Step_6 → Step_7 → Step_8 → Step_9 → Step_0 → Step_9 → Step_4 Route or Step_0 → Step_1 → Step_2 → Step_15 → Step_16 → (Step_17 →) Step_18 or Step_0 → Step_1 → Step_2 → Step_15 → Step_20 → Step_17 → Step_17 → Step_17 → Step_17 → Step_17 → Only No.

  The function of the junction circuit 45 of the second receiver 40 is as follows: Step_0 → Step_1 → Step_2 → Step_3 → Step_11, or Step_0 → Step_1 → Step_2 → Step_3 → Step_11 → Step_13 → Step_13 There are only two ways.

  If the IC card 14 is attached to both the first receiver 30 and the second receiver 40, the junction circuit 35 of the first receiver 30 and the second receiver 40 Since the first EMM or ECM received by the junction circuit 45 is always from the respective transmission / reception interface 35 and transmission / reception interface 45, the process proceeds from Step_2 in FIG. 4 to Step_3 and from Step_3 to Step_4. The terminal 37 and the bridge terminal 47 are not used, and the first receiving device 30 and the second receiving device 40 operate completely independently of each other.

  Further, if the IC card 14 is not attached to both the first receiving device 30 and the second receiving device 40, first the junctions of the first receiving device 30 and the second receiving device 40 respectively. The operation of the circuit 35 and the junction circuit 45 always proceeds to Step_3 in Step_2 of FIG. 4 and always proceeds to Step_11 from Step_3, and signals appear at both bridge terminals 37 and 47.

  Then, next, Step_2 in FIG. 4 always goes to Step_15, and Step_15 always comes to “NO”, so the process ends without finding the IC card 14 to be processed.

  In this way, a plurality of viewing contracts assigned to one IC card 14 can be used separately by the two receiving apparatuses.

  In the present invention, the amount of ECM processed by the IC card 14 per unit time is about twice that of the case where the IC card is contracted separately, but in general, the processing time of the IC card 14 is several times or more. A margin is provided, and there is no problem in increasing the processing by about twice.

  The contents of signals exchanged between the two receiving apparatuses via the bridge terminal are basically the same as the contents of signals exchanged between the single IC card 14 and the single receiving apparatus 13, and the IC card. 14 does not require any new additional information for performing authentication between the receiver 14 and the receiving device 30 and the receiving device 40. Therefore, the circuit required for the processing can be omitted, and the increase in cost can be suppressed. An increase in the amount can also be suppressed.

  Furthermore, between the receiving device 30 in which the IC card 14 is mounted on the IC card terminal 36 and the receiving device 40 in which the IC card 14 is not mounted on the IC card terminal 46, a bridge terminal provided in both receiving devices. 37 and the bridge terminal 47 are connected, and the signal flowing between them is the same as the signal flowing between the IC card 14 and the IC card terminal 36, the number of signals, the signal level, the communication protocol, etc., or the junction circuit. 35 and the junction circuit 45 are further subjected to further simple conversion, so that the risk of unauthorized use of conditional access related information does not increase at all.

  In addition, in the present invention, the current IC card already in use and used can be used as it is.

It is a typical block diagram for demonstrating the broadcast receiver of this invention. It is a typical block diagram for demonstrating the broadcast receiver of this invention. It is a typical block diagram for demonstrating the broadcast receiver of this invention. It is a flowchart explaining the operation state of the broadcast receiving apparatus of this invention.

Explanation of symbols

1: broadcast station 2: contract information 3: work key 4: work key (Kw) and contract information multiplexer 5: master key 6: work key (Kw) and contract information encryption circuit (EMM generation)
7: Program information 8: Scramble key (Ks)
9: Multiplexer for scramble key (Ks) and program information 10: Encryption circuit for scramble key (Ks) and multiplexer for program information (ECM generation)
11: Scrambler 12: Multiplexer of scrambled content and EMM and ECM 13: Receiver 14: IC card 15: Separator of scrambled content and EMM and ECM 16: Encryption / decryption circuit of work key (Kw) and contract information (EMM interpretation)
17: Separator for contracted work key (Kw) and contract information 18: Cryptographic decryption circuit (ECM interpretation) for scramble key (Ks) and program information multiplexer
19: Scramble key (Ks) after decryption and program information separator 20: Contract content verification circuit 21: Switch 22: Descrambler 23: IC card terminal 24: Controller 25: Transmission / reception interface 26: Junction circuit 27: Bridge Terminal 28: (missing number)
29: (missing number)
30: 1 first receiver 31: first receiver scrambled content and EMM / ECM separator 32: 1 first receiver descrambler 33: 1 first receiver controller 34: Transmission / reception interface of the first receiver 35: Junction circuit of the first receiver 36: IC card terminal of the first receiver 37: Bridge terminal 38 of the first receiver 38: (missing number)
39: (missing number)
40: 1 first receiver 41: first receiver scrambled content and EMM / ECM separator 42: 1 first receiver descrambler 43: 1 first receiver controller 44: Transmission / reception interface of first receiver 45: Junction circuit of first receiver 46: IC card terminal of first receiver 47: Bridge terminal of first receiver

Claims (1)

A descrambler that descrambles the encrypted data;
A transmission / reception interface connected to the descrambler and transmitting / receiving to / from the outside;
An IC card terminal for communicating with an IC card that processes conditional access information;
A junction circuit connected between the transmission / reception interface and the IC card terminal and controlling a transmission / reception direction of the limited reception information;
A bridge terminal connected to the junction circuit for communicating the limited reception information with another receiving device;
The junction circuit receives the first limited reception information input from the transmission / reception interface or the second limited reception information from the other receiving device input from the bridge terminal via the IC card terminal. A response corresponding to the first limited reception information from the IC card is transmitted to the transmission / reception interface, and a response corresponding to the second limited reception information from the IC card is transmitted to the bridge terminal. The broadcast receiving apparatus is controlled so as to transmit to the other receiving apparatus via the network.

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