JP2016116065A - Receiver, transmitter, and method for receiving content - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a receiver, transmitter, and method for receiving a content for a CAS system of MMT(MPEG Media Transport), that reduce data transmission capacity.SOLUTION: A receiver 200A receives, from a transmitter 100A, a broadcast content and communication content that are scrambled with a scramble key; and descrambles the contents by using a CAS descramble device 210A. The CAS descramble device 210A descrambles the scrambled broadcast content and communication content by using a scramble key mapped using a time stamp or identifier allocated to the broadcast content, communication content, and scramble key by the transmitter 100A.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a receiver, a transmitter, and a content receiving method for an MMT CAS system.

  In current Japanese digital broadcasting, a triple key system is used as a basic system of the CAS system. In the CAS method (TRMP) used in digital terrestrial broadcasting as an example, program content is scrambled (scrambled) using a scramble key at a broadcasting station and transmitted to a receiver. Also, an ECM (Entitlement Control Message) and an EMM (Entitlement Management Message) are transmitted from the broadcasting station to the receiver.

  Here, the ECM is obtained by encrypting a scramble key using a work key, and is data used as related information common to the receivers. The EMM is data that is obtained by encrypting a work key using an individual device key set in advance in the receiver, and is used as information related to the device ID of the receiver.

  The receiver decrypts the EMM using the device key, decrypts the ECM using the obtained work key, and descrambles the program content using the obtained scramble key.

  In such a system, the scramble key is updated periodically (for example, every 2 seconds) in consideration of security. For this reason, the ECM is also updated at the same frequency.

  There are two types of scramble keys, odd keys and even keys. Every time the scramble key is updated, content is scrambled by alternately using odd keys and even keys.

  In Japanese digital broadcasting, MPEG2-TS is used as a multiplexing method. In MPEG2-TS, the presence / absence of scramble and the presence / absence of an even key / odd key are determined using a scramble flag in the TS packet header of the content. Specify.

  The ECM stores two types of scrambled keys (even and odd keys), and matches the timing with the scrambled content so that both the key used for scramble and the key used for the next update are included. (Actually a little earlier than the content transmission).

  By doing so, the receiver is devised so that decoding is not impossible even if there is a slight difference between the switching timing of the scramble flag and the arrival timing of the ECM (for example, see Non-Patent Documents 1 and 2).

  MMT (MPEG Media Transport) has been proposed as a new multiplexing method replacing the current MPEG2-TS, and a CAS method corresponding to the MMT (MPEG Media Transport) has also been proposed (for example, see Non-Patent Document 3).

  One feature of MMT is that one service can be transmitted using a plurality of different transmission paths. For example, broadcast content transmitted via a broadcast wave and communication content transmitted via a communication network. Can be flexibly provided with a broadcasting / communication cooperation service such as combining and presenting on a TV screen.

ARIB STD-B25 “Access Control Method for Digital Broadcasting” ARIB TR-B14 “Digital Terrestrial Television Broadcasting Operation Rules (Fifth Volume)” ARIB STD-B61 “Digital Broadcast Access Control Method (2nd Generation) and CAS Program Download Method”

  In the case of the broadcast communication cooperation service as described above, when the broadcast content transmitted via the broadcast wave and the communication content transmitted via the communication network are scrambled by independent CAS systems, two independent Each CAS system requires an ECM or EMM, increasing the data transmission capacity.

  That is, the conventional MMT CAS system has a problem that the data transmission capacity is large.

  Therefore, an object of the present invention is to provide a receiver, transmitter, and content receiving method for an MMT CAS system with reduced data transmission capacity.

  The receiver according to the embodiment of the present invention is configured to scramble from a transmitter that scrambles broadcast content transmitted by a broadcast wave and communication content transmitted through a transmission path by wired communication or wireless communication using a scramble key. A receiver that receives the broadcast content and the communication content that has been transmitted, and wherein the transmitter uses the time stamp or identifier assigned to the broadcast content, the communication content, and the scramble key. And an associating unit for associating the communication content with the scramble key, and a descrambling unit for descrambling the scrambled broadcast content and communication content with the scramble key associated with the associating unit.

  It is possible to provide a receiver, a transmitter, and a content receiving method for an MMT CAS system with a reduced data transmission capacity.

1 is a diagram showing a broadcast system 1 according to Embodiment 1. FIG. 1 is a diagram showing a hybrid CAS type broadcasting system 1A according to Embodiment 1. FIG. It is a figure which shows the relationship between the scrambled content and the scramble key Ks contained in ECM. It is a figure which shows the data structure of a MMTP packet. It is a figure which shows the data structure and MMT scramble control bit of the extended area | region of a MMTP packet. It is a figure which shows the data structure of ECM. It is a figure explaining the process which the receiver 200A rearranges broadcast content, communication content, and ECM based on a time stamp. It is a flowchart which shows the process which 200A of receivers perform. FIG. 2 is a diagram illustrating a hybrid CAS type broadcasting system 2A according to a second embodiment. It is a figure which shows the data content of a scramble key database. It is a flowchart which shows the process which 300 A of receivers perform. FIG. 4 is a diagram illustrating a hybrid CAS-type broadcasting system 3A according to a third embodiment. It is a figure which shows the data structure of ECM. It is a figure explaining the process which matches the broadcast content and communication content, and ECM which were scrambled by the receiver 400A. It is a flowchart which shows the process which 400 A of receivers perform. It is a figure explaining the process which matches the broadcast content and communication content, and ECM which were scrambled by the receiver 400A. It is a figure which shows a MMT scramble control bit. It is a figure which shows the data structure of ECM. 10 is a flowchart illustrating processing executed by receiver 400A of the fourth embodiment.

  Embodiments to which the receiver, transmitter, and content receiving method of the present invention are applied will be described below.

<Embodiment 1>
FIG. 1 is a diagram illustrating a broadcasting system 1 according to the first embodiment.

  The broadcast system 1 includes a transmitter 100 and a receiver 200, and broadcasts video, audio, and other information (hereinafter referred to as program content) such as a TV program in a digital manner. In digital broadcasting, a triple key system is used as a basic system of the CAS system. The broadcast system 1 shown in FIG. 1 has a CAS system (TRMP) basic system configuration as an example.

  The transmitter 100 is installed in a broadcasting station, and the receiver 200 is installed in a viewer's house or the like. Although FIG. 1 shows one transmitter 100 and one receiver 200, in practice, a plurality of receivers 200 receive broadcasts simultaneously from one transmitter 100.

  The transmitter 100 includes a scramble device 110 and encryption devices 120 and 130.

  The scramble device 110 is a device that scrambles (encrypts) program content. The program content is encrypted by the scrambler 110 using the scramble key Ks and transmitted from the transmitter 100 to the receiver 200.

  The scramble key Ks is a key for scrambling (encrypting) program content, and is updated periodically (for example, every 2 seconds) in consideration of security. Details of the scramble key will be described later.

  The encryption device 120 encrypts the scramble key Ks using the work key Kw to generate an ECM (Entitlement Control Message). The ECM is transmitted from the transmitter 100 to the receiver 200.

  The work key Kw is a key for encrypting the scramble key. The ECM is encryption data used as related information common to the receivers, and is decrypted by the receiver 200.

  The encryption device 130 encrypts the work key Kw using the device key Kd to generate an EMM (Entitlement Management Message). The EMM is transmitted from the transmitter 100 to the receiver 200.

  The device key Kd is an individual key set in the receiver 200 and is different for each receiver 200. The device key Kd is used to encrypt the work key Kw. The transmitter 200 has a device ID that is an identifier of the plurality of receivers 200 and a device key corresponding to each device ID.

  The EMM is encrypted data used as related information corresponding to the device ID of the receiver 200 and is transmitted from the transmitter 100 to the receiver 200.

  The receiver 200 includes a descrambling device 210 and decoding devices 220 and 230. The receiver 200 receives the scrambled program content, ECM, and EMM transmitted from the transmitter 100, decodes the scrambled program content using the ECM and EMM, and outputs program content data.

  The descrambling device 210 descrambles (decrypts) the scrambled program content using the scramble key Ks. The scramble key Ks used by the descrambling device 210 is obtained by the decryption device 220 decrypting the ECM received by the receiver 200 from the transmitter 100.

  The decryption device 220 decrypts the ECM using the work key Kw and outputs the decrypted ECM to the descrambling device 210. The work key Kw used by the decryption device 220 is obtained by the decryption device 230 decrypting the EMM.

  The decryption device 230 decrypts the EMM using the device key Kd and outputs the work key Kw to the decryption device 220. The device key Kd used by the decryption device 230 is a unique key corresponding to the device ID of the receiver 200 and is held by the receiver 200.

  By the way, there is a multiplexing method such as MMT (MPEG Media Transport) in which one service is transmitted through a plurality of different transmission paths. The different transmission paths include, for example, a wireless transmission path using broadcast waves for broadcasting and a transmission path using wireless communication for a wired line such as the Internet or at least a part thereof. Broadcast using such a plurality of different transmission paths is called a hybrid type.

  In the case of such MMT, it is desirable to use one common CAS system regardless of the transmission path. For example, a receiver that receives broadcast data that is broadcast by radio waves wirelessly from an antenna of a transmitter of a broadcast station, and communication data that is communicated from the broadcast station using wired communication such as the Internet or at least partially using wireless communication. In an MMT system such that the broadcast data and the communication data are transmitted by one common CAS system.

  This is because the ECM and EMM can be shared by using one common CAS system, so that the data transmission capacity can be reduced and the cost of the system can be reduced by using one transmitter and one receiver. This is because there is a merit of being able to go down.

  In the first embodiment, such one common hybrid CAS system is provided.

  Next, a hybrid CAS broadcast system will be described with reference to FIG.

  FIG. 2 is a diagram illustrating a hybrid CAS broadcast system 1A according to the first embodiment. A broadcasting system 1A shown in FIG. 2 corresponds to the hybrid CAS system of the broadcasting system 1 shown in FIG.

  The broadcast system 1A includes a transmitter 100A and a receiver 200A.

  The transmitter 100A includes a scrambler 110A, an MMT multiplexer (hereinafter referred to as MMTMUX) 140, and a separator 150. The scrambler 110A corresponds to the scrambler 110 of the transmitter 100 of FIG.

  Of the transmitter 100A, at least the scrambler 110A is configured by a computer or a CPU (Central Processing Unit) chip.

  The receiver 200 </ b> A includes a main control unit 201, a combiner 240, a reception buffer 250, an MMT packet switch 260, a CAS descrambling device 210 </ b> A, and an MMT demultiplexer (hereinafter referred to as “MMTDEMUX”) 270.

  Of the receiver 200A, at least the main control unit 201, the MMT packet switch 260, and the CAS descrambling device 210A are configured by a computer or a CPU chip.

  The transmitter 100A includes an encryption device similar to the encryption devices 120 and 130 shown in FIG. 1, but is omitted here. In FIG. 2, ECM and EMM created by an encryption device similar to the encryption devices 120 and 130 shown in FIG. 1 are input to the MMTMUX 140 together with broadcast content and communication content.

  Note that the scramble key Ks created by the CAS scrambler 110A is fed back to the encryption device similar to the encryption devices 120 and 130 shown in FIG. 1 and used for ECM creation. Created.

  Broadcast content and communication content are input to the transmitter 100A. Broadcast content is content corresponding to the program content shown in FIG. 1 (video, audio, and other information such as television programs). The communication content is information related to the broadcast content, or information such as a weather forecast not directly related to the broadcast content, and is transmitted through a wired line such as the Internet or at least a part of the transmission path using wireless communication. Content.

  Broadcast content and communication content are transmitted as digital data.

  The MMTMUX 140 is a device that multiplexes broadcast content, communication content, ECM, and EMM and outputs one data. The MMTMUX 140 sequentially selects EMM, ECM, broadcast content, and communication content one by one, and outputs multiplexed MMTP packet format data (hereinafter referred to as MMTP packet) to the scrambler 110A.

  In addition, the MMTMUX 140 gives a time stamp to each MMTP packet. For this reason, MMTP packets including EMM, ECM, broadcast content, and communication content have different time stamps.

  The CAS scrambler 110A scrambles the MMTP packet of the broadcast content and the communication content using the scramble key Ks and outputs it to the separator 150. The CAS scrambler 110 </ b> A outputs the EMM and ECM MMTP packets to the separator 150.

  Separator 150 scrambles broadcast content and communication content MMTP packets scrambled by scrambler 110A, MMTP packets of EMM and ECM input from scrambler 110A, MMTP packets of broadcast content, EMM, and ECM, Separated and output to MMTP packet of communication content.

  Broadcast content, EMM, and ECM MMTP packets are radiated from the antenna of the transmitter 100A and transmitted to the receiver 200A by broadcast waves. This is, for example, data A output from the separator 150, and is transmitted to the receiver 200A by a broadcast wave.

  The MMTP packet of communication content is transmitted from the transmitter 100A to the receiver 200A through a wired line such as the Internet or a transmission path using wireless communication at least in part. This is, for example, data B output from the separator 150, and is transmitted to the receiver 200A via a wired communication or a transmission path using at least a part of wireless communication.

  The order of the MMTP packets transmitted by the transmitter 100A is such that EMM is transmitted first, then ECM is transmitted, and broadcast content or communication content is transmitted after EMM and ECM. Either order may be sufficient as the order which transmits broadcast content and communication content.

  The receiver 200A receives the MMTP packets of EMM, ECM, and broadcast content that are radiated from the antenna of the transmitter 100A and transmitted by broadcast waves via the antenna, and is connected to the wired line such as the Internet or the like from the transmitter 100A. An MMTP packet of communication content transmitted through a transmission path using at least a part of wireless communication is received. Note that the MMTP packets for broadcast content and communication content are scrambled.

  The main control unit 201 supervises the processing of the combiner 240, the reception buffer 250, the MMT packet switch 260, the CAS descrambling device 210A, and the MMTDEMUX 270.

  The combiner 240 combines the MMTP packet of EMM, ECM, and broadcast content and the MMTP packet of communication content, and outputs it to the reception buffer 250.

  The reception buffer 250 is a memory built in the receiver 200A, and temporarily stores MMTP packets of EMM, ECM, broadcast content, and communication content input from the synthesizer 240.

  When the amount of EMM, ECM, broadcast content, and communication content MMTP packets stored in the reception buffer 250 reaches the upper limit, the EMM, ECM, broadcast content, and communication content MMTP packets stored in the reception buffer 250 Is read to the MMT packet switch 260.

  The MMT packet switch 260 rearranges the MMTP packets of the EMM, ECM, broadcast content, and communication content read from the reception buffer 250 in the order of time stamps, and outputs them to the CAS descrambler 210A.

  The MMT packet switch 260 outputs MMTP packets of EMM, ECM, broadcast content, and communication content arranged in time series based on the time stamp. As a result, the EMM and the ECM are associated with the broadcast content or the communication content based on the time stamp. Therefore, the MMTP packet switch 260 is an example of an association unit. The time stamp represents the time when the transmitter 100A transmits.

  The CAS descrambler 210A is a device in which the scrambler 210 of the receiver 200 of FIG. 1 is made compatible with the hybrid CAS method, and includes the functions of the decoders 220 and 230 shown in FIG.

  The CAS descrambling apparatus 210A receives EMM, ECM, scrambled broadcast content, and scrambled communication content MMTP packets from the MMT packet switch 260.

  The CAS descrambler 210A decrypts the EMM using the device key Kd to extract the work key Kw, and uses the work key Kw to decrypt the ECM to extract the scramble key Ks. Then, CAS descrambling apparatus 210A descrambles (decodes) the scrambled broadcast content and the scrambled communication content using scramble key Ks, and outputs the broadcast content and the communication content to MMTDEMUX 270. .

  The MMTDEMUX 270 outputs the descrambled broadcast content and communication content separately for the broadcast content and the communication content. As a result, the broadcast content and the communication content are combined and presented on the TV screen.

  FIG. 3 is a diagram showing the relationship between the scrambled content and the scramble key Ks included in the ECM. The scrambled content is scrambled broadcast content or communication content.

  In FIG. 3, the scrambled content shown on the upper side includes broadcast content 301 and 302, communication content 303 and 304, broadcast content 305, and the like included in an MMTP packet having a plurality of time stamps allocated in time series. It is.

  Broadcast contents 301 and 302, communication contents 303 and 304, and broadcast contents 305 are scrambled with scramble keys Ks-a, Ks-b, Ks-c, Ks-d, and Ks-e, respectively. Odd indicates that the scramble key is an odd number, and Even indicates that the scramble key is an even number.

  Further, ECM data shown on the lower side of FIG. 3 is ECMs 401, 402, 403, 404, and 405 included in an MMTP packet having a plurality of time stamps allocated in time series.

  Each of the ECMs 401 to 405 includes two scramble keys. The two scramble keys are a key used for the scramble at that time and a key used for the next update, and the key used for the scramble and the key used for the next update are alternately headed in the two areas. Arranged to come to.

  Also, the broadcast contents 301 and 302, the communication contents 303 and 304, the broadcast contents 305, and the ECMs 401, 402, 403, 404, and 405 are associated with each other as indicated by the lines shown therebetween.

  There are two types of scramble keys, an odd key (O: Odd) and an even key (E: Even), and they are generated alternately. For this reason, each of the ECMs 401 to 405 includes an odd number of scramble keys and an even number of scramble keys.

  Here, the MMT packet switch 260 rearranges the content read from the reception buffer 250 and the ECM and EMM in the order of the time stamp when the transmission path using wireless communication is transmitted to a wired line such as the Internet or at least partly. The transmission time may be different between the broadcast content transmitted by broadcast waves, the ECM, and the EMM. If the transmission time is different, the communication content and the broadcast content are descrambled with a scramble key that should be used originally. This is because there is a possibility that it cannot be scrambled.

  In general, it is considered that data transmitted through a wired line such as the Internet or at least a part of a transmission path using wireless communication is delayed than data transmitted by a broadcast wave. The reverse situation may occur.

  In order to prevent the descrambling from being disabled in this way, the MMT packet switch 260 rearranges the content read from the reception buffer 250, the ECM, and the EMM in order of the time stamp.

  Next, the data structure of the MMTP packet will be described with reference to FIG.

  FIG. 4 is a diagram illustrating a data structure of the MMTP packet.

  The MMTP packet includes a timestamp, an extension area (extension_type, extension_length, header_extension_byte), and a payload.

  The time stamp has a data capacity of 32 bits and holds the time stamp. The payload (MMTP_payload) holds any one of ECM, EMM, broadcast content, or communication content.

  Next, the MMT scramble control bit indicating the presence / absence of scramble will be described with reference to FIG.

  FIG. 5 is a diagram showing the data structure of the extension area of the MMTP packet and the MMT scramble control bits.

  In FIG. 5A, the extension area of the MMTP packet has a data area from the first multi-extension header type to the last MMT scramble initial value information. After the MMT scramble initial value information, there are an MMTP payload corresponding to the payload (MMTP_payload) shown in FIG. 4 and a message authentication code. The message authentication code is a code used for preventing falsification and the like, and since it is not directly related here, description thereof is omitted.

  In the first embodiment, the MMT scramble control bit indicating the presence / absence of scramble is stored in the fourth area from the beginning of the extension area.

  The MMT scramble control bit is a bit provided in the MMTP packet of the broadcast content and the communication content, and as shown in FIG. 5B, the presence / absence of scramble and whether the scramble key is even or odd is represented by 2 bits. When the MMT scramble control bit is 00, it indicates no scramble, 01 is not defined, 10 is scrambled by an even number of scramble keys, and 11 is scrambled by an odd number of scramble keys.

  Next, an ECM data structure will be described with reference to FIG.

  FIG. 6 shows the data structure of ECM. Such ECM data is stored in the MMTP payload of the MMTP packet.

  FIG. 6 shows an ECM-F1 main body portion of the ECM data structure. The ECM-F1 main body includes a fixed part and a variable part of the encryption part. The variable part has data areas up to scramble keys 0 (Odd), 0 (Even),..., N-1 (Odd), n-1 (Even), but the ECM includes odd numbers. Since it is an even set of scramble keys, a common scramble key for each pair is stored in each of 0 (Odd), 0 (Even), ..., n-1 (Odd), and n-1 (Even). Is done. The encryption unit is encrypted with n different types of work keys Kw, but portions other than the encryption unit are not encrypted.

  Next, processing for rearranging broadcast content, communication content, and ECM received by the receiver 200A based on the time stamp will be described with reference to FIG.

  FIG. 7 is a diagram illustrating processing in which the receiver 200A rearranges broadcast content, communication content, and ECM based on a time stamp.

  The transmitter 100A transmits the broadcast contents 311 and 312, the communication contents 313 and 314, and the ECMs 411 and 412 illustrated in FIG. Among these, the broadcast contents 311 and 312 and the communication contents 313 and 314 are scrambled by the CAS scrambler 110A.

  In FIG. 7A, the 9-digit numerical values shown below the broadcast contents 311 and 312, the communication contents 313 and 314, and the ECMs 411 and 412 indicate the time represented by the time stamp, and the smaller the numerical value, the earlier the time. The larger the value, the later the time.

  The broadcast content 311, the communication content 313, and the ECM 411 have numerical timestamps that are close to each other. The broadcast content 311 and the communication content 313 are scrambled with the leading Ks-a of the two scramble keys Ks-a and Ks-b included in the ECM 411.

  Also, the broadcast content 312, the communication content 314, and the ECM 412 have time stamps that are close to each other. The broadcast content 312 and the communication content 314 are scrambled with the back scramble key Ks-b of the two scramble keys Ks-c and Ks-b included in the ECM 412.

  Arranged in order from the data with the earliest time stamp, the ECM 411, the broadcast content 311, the communication content 313, the ECM 412, the broadcast content 312, and the communication content 314 are arranged in this order.

  Such scrambled broadcast contents 311 and 312, communication contents 313 and 314, and ECMs 411 and 412 are transmitted from the transmitter 100A, and the scrambled broadcast contents 311 and 312 and ECMs 411 and 412 are transmitted by broadcast waves. Assume that the scrambled communication contents 313 and 314 transmitted and received by the receiver 200A are received by the receiver 200A via a wired line or a transmission path using wireless communication at least in part.

  Then, it is assumed that the scrambled communication contents 313 and 314 are received by the receiver 200A after the scrambled broadcast contents 311 and 312 and the ECMs 411 and 412.

  As shown in FIG. 7B, the MMTP packets received by the receiver 200A are in the order of ECM411, broadcast content 311, ECM412, broadcast content 312, communication content 313, and communication content 314. Suppose that the receiver 200A receives the ECM 412 and the broadcast content 312 later.

  In this way, the ECM 411, the broadcast content 311, the ECM 412, the broadcast content 312, the communication content 313, and the communication content 314 received by the receiver 200A are stored in the reception buffer 250 in the order received.

  In such a case, when the data amount of the MMTP packet stored in the reception buffer 250 reaches the upper limit of the memory capacity of the reception buffer 250, the MMT packet switch 260 converts the MMTP packet stored in the reception buffer 250 to the time. By reading the stamps in order from the earliest, the MMTP packets are rearranged in the order of the time stamps.

  Therefore, the MMTP packets output from the MMT packet switch 260 are in the order of ECM411, broadcast content 311, communication content 313, ECM412, broadcast content 312, and communication content 314 as shown in FIG. Between FIG. 7B and FIG. 7C, MMTP packets rearranged by arrows are shown.

  Next, processing executed by the receiver 200A will be described with reference to FIG.

  FIG. 8 is a flowchart illustrating processing executed by the receiver 200A.

  The receiver 200A starts processing when the power is turned on (start).

  The receiver 200A receives the MMTP packet (step S1).

  The main control unit 201 of the receiver 200A calculates the packet size of the received MMTP packet (step S2). At this time, the main control unit 201 calculates the free capacity of the reception buffer 250. The free space of the reception buffer 250 can be obtained by subtracting the packet size of the MMTP packet stored in the reception buffer 250 from the upper limit value of the reception buffer 250 after the reception buffer 250 is reset.

  The main control unit 201 of the receiver 200A determines whether the packet size calculated in step S2 is less than or equal to the free capacity of the reception buffer 250 (step S3).

  When the main control unit 201 of the receiver 200A determines that the packet size is equal to or larger than the free capacity of the reception buffer 250 (S3: Yes), the main control unit 201 stores (stores) the MMTP packet in which the packet size is calculated in the reception buffer 250 (step) S4).

  At this time, the reception buffer 250 stores MMTP packets in the order received by the receiver 200A. That is, when the communication content 313 illustrated in FIG. 7A is received by the receiver 200A later than the ECM 412 and the broadcast content 312, the communication content 313 is transmitted to the ECM 412 and the broadcast content as illustrated in FIG. It is stored in the reception buffer 250 after the content 312.

  Next, the main control unit 201 of the receiver 200A returns the flow to step S1. When it is determined in step S3 that the packet size calculated in step S2 is not less than the free capacity of the reception buffer 250 (S3: No) by repeatedly executing the processes of steps S1 to S4, the receiver 200A The main control unit 201 causes the MMT packet switch 260 to read out the MMTP packets stored in the reception buffer 250 in order from the earliest time stamp. Thereby, the MMT packet switch 260 rearranges the MMTP packets in the order of the time stamps (step S5).

  Note that the MMT packet switch 260 outputs the MMTP packets to the CAS descrambling apparatus 210A while rearranging the MMTP packets in the order of the time stamps.

  Therefore, when MMTP packets are stored in the receiving buffer 250 in the order of ECM411, broadcast content 311, ECM412, broadcast content 312, communication content 313, and communication content 314 as shown in FIG. As shown in FIG. 7C, the MMTP packets output from the MMT packet switch 260 are in the order of ECM411, broadcast content 311, communication content 313, ECM412, broadcast content 312, and communication content 314.

  As described above, according to the first embodiment, a delay due to a difference in transmission time occurs between different transmission paths in one common CAS-type broadcasting system 1A used for a plurality of different transmission paths. Even in this case, it is possible to provide the receiver 200A that can output contents in the order in which the transmitter 100A transmits.

  Further, since the receiver 200A can output contents in the order of transmission by the transmitter 100A, it is possible to provide an MMT broadcasting system 1A with a reduced data transmission capacity.

  As described above, according to the first embodiment, it is possible to provide an MMT broadcasting system 1A with a reduced data transmission capacity, and a receiver 200A and a transmitter 100A for the broadcasting system 1A.

<Embodiment 2>
FIG. 9 is a diagram showing a hybrid CAS broadcast system 2A according to the second embodiment. A broadcast system 2A shown in FIG. 9 is a modification of the broadcast system 1A of the first embodiment shown in FIG.

  The broadcast system 2A includes a transmitter 100A and a receiver 300A. Transmitter 100A is the same as transmitter 100A of the first embodiment shown in FIG.

  The receiver 300A includes a main control unit 390, a synthesizer 240, an ECM packet analysis unit 350, a scramble key management unit 360, a scramble key extraction unit 370, a content packet analysis unit 380, a CAS descrambling device 310A, and an MMTDEMUX 270.

  Of the receiver 300A, at least the main control unit 390, the ECM packet analysis unit 350, the scramble key extraction unit 370, the content packet analysis unit 380, and the CAS descrambling device 310A are configured by a computer or a CPU chip.

  Hereinafter, the same components as those of the receiver 200A of Embodiment 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The receiver 300A receives MMTP packets of EMM, ECM, and broadcast content radiated from the antenna of the transmitter 100A and transmitted by broadcast waves via the antenna, and is connected to the wired line such as the Internet or the like from the transmitter 100A. An MMTP packet of communication content transmitted through a transmission path using at least a part of wireless communication is received. Note that the MMTP packets for broadcast content and communication content are scrambled.

  The main control unit 390 supervises the processes of the combiner 240, the ECM packet analysis unit 350, the scramble key management unit 360, the scramble key extraction unit 370, the content packet analysis unit 380, the CAS descrambler 310A, and the MMTDEMUX 270.

  The combiner 240 combines the EMM, ECM, and broadcast content MMTP packets with the communication content MMTP packets and outputs them to the ECM packet analysis unit 350.

  The ECM packet analysis unit 350 receives EMM, ECM, scrambled broadcast content, and scrambled communication content MMTP packets from the combiner 240.

  The ECM packet analysis unit 350 decrypts the EMM using the device key Kd to retrieve the work key Kw, and decrypts the ECM using the work key Kw to retrieve the scramble key Ks. Then, the ECM packet analysis unit 350 outputs the scramble key Ks to the scramble key management unit 360.

  Further, the ECM packet analysis unit 350 outputs the MMTP packet of the broadcast content and the MMTP packet of the communication content to the content packet analysis unit 380.

  The scramble key management unit 360 arranges the scramble key Ks input from the ECM packet analysis unit 350 in order according to the time stamp of the scramble key Ks and stores it in the internal memory. The time stamp of the scramble key Ks is a time stamp given to the MTTP packet including the ECM that stores the scramble key Ks. Since the ECM stores even scramble keys and odd scramble keys, there are even scramble keys and odd scramble keys having the same time stamp.

  Data in which the scramble key management unit 360 stores the scramble key Ks in order in accordance with the time stamp stored in the internal memory is referred to as a scramble key database. The scramble key database will be described later with reference to FIG.

  The scramble key management unit 360 makes the scramble key extraction unit 370 refer to the scramble key database.

  The scramble key extraction unit 370 receives data representing a time stamp included in the MMTP packet of broadcast content and communication content from the content packet analysis unit 380.

  The scramble key extraction unit 370 refers to the scramble key database, and extracts a scramble key whose difference from the time stamp input from the content packet analysis unit 380 is a predetermined threshold value or less.

  MMTP packets including EMM, ECM, broadcast content, and communication content have different time stamps. That is, the time stamp value is different for each MMTP packet. For this reason, in the second embodiment, the scramble key extraction unit 370 extracts the scramble key Ks whose difference from the time stamp input from the content packet analysis unit 380 is equal to or less than a predetermined threshold and inputs the scramble key Ks to the CAS descrambling apparatus 310A. To do. As a result, the broadcast content or the communication content is associated with the corresponding scramble key. The scramble key extraction unit 370 is an example of an association unit.

  The content packet analysis unit 380 analyzes (reads) the time stamp included in the MMTP packet of the broadcast content and communication content input from the ECM packet analysis unit 350 and outputs the time stamp to the scramble key extraction unit 370 and the CAS descrambling device 310A. .

  The CAS descrambling device 310A descrambles the MMTP packet of the broadcast content and the communication content input from the content packet analysis unit 380 using the scramble key Ks input from the scramble key extraction unit 370. Then, CAS descrambling apparatus 310A outputs descrambled MMTP packets of broadcast content and communication content to MMTDEMUX 270.

  As a result, the MMT DEMUX 270 outputs the broadcast content and the communication content separately, and the broadcast content and the communication content are combined and presented on the TV screen.

  FIG. 10 shows the data contents of the scramble key database.

  The scramble key database is data in which the scramble key Ks decrypted by the ECM packet analysis unit 350 is arranged in time series according to the time stamp, and is stored in the internal memory by the scramble key management unit 360.

  As shown in FIG. 10, in the scramble key database, a time stamp, an odd (Odd) scramble key, and an even (Even) scramble key are associated.

  In this way, in the scramble key database, even scramble keys and odd scramble keys for the same time stamp are stored in association with each other.

  Next, processing executed by the receiver 300A will be described with reference to FIG.

  FIG. 11 is a flowchart illustrating processing executed by the receiver 300A.

  The receiver 300A starts processing (starts) when the power is turned on.

  The receiver 300A receives the MMTP packet (step S21).

  The main controller 390 of the receiver 300A determines whether or not the received MMTP packet includes an ECM (step S22). Whether or not it is an ECM can be determined, for example, by reading a packet ID (packet ID: see FIG. 4) included in the MMTP packet. The packet ID includes information indicating whether the EMM, ECM, broadcast content, or communication content is included in the payload of the MMTP packet. Note that these are merely examples of operations and are not necessarily included.

  If the main control unit 390 of the receiver 300A determines that it is an ECM (S22: Yes), it stores the time stamp and the scramble key Ks in the scramble key database of the scramble key management unit 360 (step S23). At this time, the scramble key Ks stored in association with the time stamp is both an even key (Even) and an odd key (Odd). When the process of step S23 ends, the main control unit 390 of the receiver 300A ends the flow. Then, the flow is started again.

  If the main control unit 390 of the receiver 300A determines that it is not an ECM (S22: No), it determines whether it is scrambled broadcast content or communication content (step S24).

  If the main control unit 390 of the receiver 300A determines that the content is scrambled broadcast content or communication content (S24: Yes), it causes the content packet analysis unit 380 to analyze the time stamp of the MMTP packet (step S25). At this time, the content packet analysis unit 380 analyzes the time stamp of the broadcast content or communication content MMTP packet input from the ECM packet analysis unit 350 and outputs the MMTP packet time stamp to the scramble key extraction unit 370.

  The scramble key extraction unit 370 refers to the scramble key database, and extracts a scramble key whose difference from the time stamp input from the content packet analysis unit 380 is a predetermined threshold value or less (step S26).

  The main control unit 390 reads the value of the MMT scramble control bit of the MMTP packet of the broadcast content or communication content input to the content packet analysis unit 380, and reads the odd key (Odd) or even key (scramble key extracted in step S26). (Even) to specify which of the two is scrambled (step S27).

  Note that the content packet analysis unit 380 may perform the processing in step S27.

  The main control unit 390 causes the scramble key extraction unit 370 to transmit one of the odd key (Odd) and the even key (Even) identified in step S27 to the CAS descrambling device 310A (step S28).

  If the main control unit 390 determines in step S24 that the content is not scrambled broadcast content or communication content (S24: No), the process is terminated.

  Thus, a series of processing ends. The flow shown in FIG. 11 is executed under the overall control of the main control unit 390, and is executed every time an MMTP packet is received.

  As a result of the above processing, the CAS descrambling apparatus 310A uses the scramble key Ks input from the scramble key extraction unit 370 to decrypt the MMTP packet of the broadcast content and communication content input from the content packet analysis unit 380. The scrambled and descrambled broadcast content and communication content MMTP packets are output to MMTDEMUX 270.

  The MMT DEMUX 270 outputs the broadcast content and the communication content separately, and the broadcast content and the communication content are combined and presented on the TV screen.

  As described above, according to the second embodiment, in a common CAS-type broadcasting system 2A used for a plurality of different transmission paths, a delay due to a difference in transmission time occurs between different transmission paths. Even in this case, it is possible to provide the receiver 300A that can output contents in the order in which the transmitter 100A transmits.

  In addition, since the receiver 300A can output contents in the order of transmission by the transmitter 100A, it is possible to provide an MMT broadcasting system 2A with a reduced data transmission capacity.

  As described above, according to the second embodiment, it is possible to provide an MMT broadcasting system 2A with a reduced data transmission capacity, and a receiver 300A and a transmitter 100A for the broadcasting system 2A.

<Embodiment 3>
FIG. 12 is a diagram showing a hybrid CAS broadcast system 3A according to the third embodiment. A broadcast system 3A shown in FIG. 12 is a modification of the broadcast system 1A of the first embodiment shown in FIG.

  The broadcast system 3A includes a transmitter 100B and a receiver 400A.

  The transmitter 100B includes a scrambler 110A, an MMTMUX 140, and a separator 150. The transmitter 100B is obtained by adding a sequence number specifying unit 160 to the transmitter 100A of FIG. Of the transmitter 100B, at least the scrambler 110A and the sequence number designation unit 160 are configured by a computer or a CPU chip.

  The sequence number designating unit 160 inputs the sequence number into the reserve area (see FIG. 5) third from the beginning of the extension area of the MMTP packet of the broadcast content and communication content. The sequence number is a 3-bit serial number and is stored in the reserved area of the extended area of the MMTP packet for only broadcast content and communication content. The reserved area is included in the extended area that is not scrambled.

  Note that the sequence number is not stored in the reserved area of the extended area of the EMM and ECM MMTP packets.

  In addition, the sequence number designating unit 160 assigns the same number as the sequence number assigned to the broadcast content and the communication content to the ECM MMTP packet. Since the ECM includes odd and even scramble keys, assigning an ECM to a sequence number is synonymous with assigning a sequence number to a scramble key.

  Here, the sequence number is an example of an identifier, and the sequence number specifying unit 160 is an example of an identifier assigning unit.

  The sequence number assigned to the ECM is stored in an area added to the ECM data structure. This will be described later with reference to FIG. Also, sequence numbers are not assigned to EMMs.

  As described above, when a 3-bit sequence number is used to allocate a scramble key, when the scramble key is updated every 2 seconds, the same sequence number does not appear for 16 seconds. That is, if the difference in transmission time between communication content and ECM is less than 16 seconds, the same sequence number cannot appear. The number of bits of the sequence number may be determined in consideration of such a difference in transmission time.

  In the broadcasting system 3A of Embodiment 3, the same sequence number is allocated to the broadcast content and communication content, and the ECM corresponding to the broadcast content and communication content, and the broadcast content and communication content are used by using the sequence number on the receiver 400A side. Is associated with ECM and descrambled.

  The receiver 400A includes a main control unit 401, a combiner 240, an ECM packet analysis unit 450, an ECM management unit 460, an ECM extraction unit 470, a content packet analysis unit 480, a CAS descrambling device 410A, and an MMTDEMUX 270.

  Of the receiver 400A, at least the main control unit 401, the ECM packet analysis unit 450, the ECM extraction unit 470, the content packet analysis unit 480, and the CAS descrambling device 410A are configured by a computer or a CPU chip.

  Hereinafter, the same components as those of the receiver 200A of Embodiment 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The receiver 400A receives the MMTP packets of EMM, ECM, and broadcast content that are radiated from the antenna of the transmitter 100B and transmitted by broadcast waves via the antenna, and is connected to the wired line such as the Internet or the like from the transmitter 100B. An MMTP packet of communication content transmitted through a transmission path using at least a part of wireless communication is received. Note that the MMTP packets for broadcast content and communication content are scrambled.

  The main control unit 401 controls the processing of the combiner 240, the ECM packet analysis unit 450, the ECM management unit 460, the ECM extraction unit 470, the content packet analysis unit 480, the CAS descrambling device 410A, and the MMTDEMUX 270.

  The synthesizer 240 synthesizes the EMM, ECM, and broadcast content MMTP packets with the communication content MMTP packets, and outputs them to the ECM packet analysis unit 450.

  The ECM packet analyzer 450 receives EMM, ECM, scrambled broadcast content, and scrambled communication content MMTP packets from the combiner 240.

  The ECM packet analysis unit 450 analyzes the MMTP packet input from the synthesizer 240 and outputs the MMTP packet of the ECM to the ECM management unit 460, and the MMTP packet of EEM, broadcast content, and communication content is a content packet analysis unit Output to 480. The ECM packet analysis unit 450 determines, for example, EMM, ECM, scrambled broadcast content, and scrambled MMTP packet of communication content based on the packet ID.

  The ECM management unit 460 has a memory area, and stores the ECM MMTP packet input from the ECM packet analysis unit 450 in the memory area. The MMTP packet managed by the ECM management unit 460 is referred to by the ECM extraction unit 470.

  Data representing the sequence number included in the MMTP packet of the broadcast content and the communication content is input from the content packet analysis unit 480 to the ECM extraction unit 470.

  The ECM extraction unit 470 refers to the memory area of the ECM management unit 460, extracts an ECM assigned with the same sequence number as the sequence number input from the content packet analysis unit 480, and extracts the extracted ECM from the CAS descrambling device Input to 410A. As a result, the broadcast content or the communication content is associated with the corresponding ECM. The ECM extraction unit 470 is an example of an association unit.

  The content packet analysis unit 480 analyzes (reads) sequence numbers included in the MMTP packets of the broadcast content and communication content input from the ECM packet analysis unit 450, and outputs them to the ECM extraction unit 470 and the CAS descrambling device 410A.

  The CAS descrambler 410A uses the device key Kd to decrypt the EMM input from the content packet analysis unit 480 to extract the work key Kw, and uses the work key Kw to output the ECM input from the ECM extraction unit 470. Decrypt and take out the scramble key Ks. Then, CAS descrambling apparatus 410A descrambles the scrambled broadcast content and communication content MMTP packets using scramble key Ks.

  Then, CAS descrambling apparatus 410A outputs descrambled MMTP packets of broadcast content and communication content to MMTDEMUX 270.

  As a result, the MMT DEMUX 270 outputs the broadcast content and the communication content separately, and the broadcast content and the communication content are combined and presented on the TV screen.

  Next, the ECM data structure will be described with reference to FIG.

  FIG. 13 shows an ECM data structure.

  FIG. 13 shows a part of the ECM-F1 main body in the ECM data structure. In Embodiment 3, the sequence number assigned to the ECM is stored in a 1-byte area below the number of scramble key pairs in the fixed part of the ECM.

  FIG. 14 is a diagram for explaining processing for associating ECM with broadcast content and communication content scrambled by receiver 400A. Here, the scrambled broadcast content is referred to as content without distinction.

  The contents 311A, 312A, 313A, 314A, and 315A are scrambled using scramble keys Ks-a, Ks-b, Ks-c, Ks-d, and Ks-e, respectively. The scramble keys Ks-a, Ks-b, Ks-c, Ks-d, and Ks-e are an odd key, an even key, an odd key, an even key, and an odd key, respectively.

  The contents 311A, 312A, 313A, 314A, and 315A are assigned 000, 001, 010, 011, and 100 as 3-bit sequence numbers, respectively.

  Each of the ECMs 411A, 412A, 413A, 414A, and 415A shown on the lower side of FIG. 14 includes two scramble keys. The two scramble keys are a key used for the scramble at that time and a key used for the next update, and the key used for the scramble and the key used for the next update are alternately headed in the two areas. Arranged to come to.

  In addition, 000, 001, 010, 011 and 100 are allocated to the ECMs 411A, 412A, 413A, 414A and 415A as 3-bit sequence numbers.

  Therefore, if the 3-bit sequence numbers 000, 001, 010, 011 and 100 are used, the scrambled content can be associated with the ECM.

  In FIG. 14, the contents 311A, 312A, 313A, 314A, 315A and the odd key (O) or even key (E) included in the ECMs 411A, 412A, 413A, 414A, 415A are represented by the lines shown between them. Is associated with.

  Next, processing executed by the receiver 400A will be described with reference to FIG.

  FIG. 15 is a flowchart illustrating processing executed by the receiver 400A.

  The receiver 400A starts processing when the power is turned on (start).

  The receiver 400A receives the MMTP packet (step S31).

  The main control unit 401 of the receiver 400A determines whether or not the received MMTP packet includes an ECM (step S32). Whether or not it is an ECM can be determined, for example, by reading a packet ID (packet ID: see FIG. 4) included in the MMTP packet. The packet ID includes information indicating whether the EMM, ECM, broadcast content, or communication content is included in the payload of the MMTP packet.

  When determining that the ECM is the ECM (S32: Yes), the main control unit 401 of the receiver 400A stores the ECM in the data area of the ECM management unit 460 (step S33). When the process of step S33 ends, the main control unit 401 of the receiver 400A ends the flow. Then, the flow is started again.

  If the main control unit 401 of the receiver 400A determines that it is not an ECM (S32: No), it determines whether it is scrambled broadcast content or communication content (step S34).

  If the main control unit 401 of the receiver 400A determines that the content is scrambled broadcast content or communication content (S34: Yes), the sequence number of the MMTP packet of the broadcast content or communication content scrambled by the content packet analysis unit 480 is set. Extraction (analysis) is performed (step S35). At this time, the content packet analysis unit 480 analyzes the sequence number of the MMTP packet of the broadcast content or communication content input from the ECM packet analysis unit 450 and outputs it to the ECM extraction unit 470.

  The ECM extraction unit 470 refers to the data area of the ECM management unit 460, and extracts an ECM having a sequence number that is the same as the sequence number input from the content packet analysis unit 480 (the value matches) (step S36).

  The main control unit 401 reads the value of the MMT scramble control bit of the MMTP packet of the broadcast content or communication content input to the content packet analysis unit 480, and extracts the odd key (Odd) or even key (scramble key extracted in step S36). (Even) is specified (step S37).

  Note that the content packet analysis unit 480 may perform the processing in step S37.

  The main control unit 401 causes the scramble key extraction unit 370 to transmit the ECM extracted in step S36 to the CAS descrambling apparatus 410A (step S38).

  If the main control unit 401 determines in step S34 that the broadcast content or communication content is not scrambled (S34: No), the process is terminated.

  Thus, a series of processing ends. The flow shown in FIG. 15 is executed under the overall control of the main control unit 401, and is executed every time an MMTP packet is received.

  As a result of the above processing, the CAS descrambling apparatus 410A uses the device key Kd to decrypt the EMM input from the content packet analysis unit 480, extracts the work key Kw, and extracts the ECM using the work key Kw. The ECM input from the unit 470 is decrypted to extract the scramble key Ks. Then, the CAS descrambler 410A scrambles using any one of the odd key (Odd) and the even key (Even) specified in step S37 among the even key and the odd key included in the scramble key Ks. The descrambled MMTP packet of the broadcast content and communication content.

  The descrambled MMTP packet of the broadcast content and communication content is output to MMTDEMUX 270.

  The MMT DEMUX 270 outputs the broadcast content and the communication content separately, and the broadcast content and the communication content are combined and presented on the TV screen.

  As described above, according to the third embodiment, in a common CAS system broadcasting system 3A that is a hybrid type and is used for a plurality of different transmission paths, there is a delay due to a difference in transmission time between different transmission paths. Even in such a case, it is possible to provide the receiver 400A that can output the contents in the order of transmission by the transmitter 100B.

  In addition, since the receiver 400A can output contents in the order of transmission by the transmitter 100B, it is possible to provide the MMT broadcasting system 3A with a reduced data transmission capacity.

  As described above, according to the third embodiment, it is possible to provide an MMT broadcasting system 3A with a reduced data transmission capacity, and a receiver 400A and a transmitter 100A for the broadcasting system 3A.

<Embodiment 4>
The fourth embodiment is a modification in the case where the scramble key is not divided into an odd key and an even key in the broadcasting system 3A of the third embodiment, and is composed of only one type of scramble key. For this reason, the configuration of the broadcast system 3A will be described with reference to FIG.

  FIG. 16 is a diagram for explaining processing for associating ECM with broadcast content and communication content scrambled by receiver 400A. Here, the scrambled broadcast content is referred to as content without distinction.

  The contents 311B, 312B, 313B, 314B, and 315B are scrambled using scramble keys Ks-a, Ks-b, Ks-c, Ks-d, and Ks-e, respectively.

  The contents 311B, 312B, 313B, 314B, and 315B are assigned 000, 001, 010, 011, and 100 as 3-bit sequence numbers, respectively.

  Further, the ECMs 411B, 412B, 413B, 414B, and 415B shown on the lower side of FIG. 16 include one type of scramble key. One type of scrambling key is a key used for scrambling at that time.

  In addition, 000, 001, 010, 011 and 100 are assigned as 3-bit sequence numbers to the ECMs 411B, 412B, 413B, 414B and 415B.

  Therefore, if the 3-bit sequence numbers 000, 001, 010, 011 and 100 are used, the scrambled content can be associated with the ECM.

  In FIG. 16, the contents 311B, 312B, 313B, 314B, and 315B and the keys included in the ECMs 411B, 412B, 413B, 414B, and 415B are associated with each other as indicated by the lines shown therebetween.

  Next, the MMT scramble control bit indicating the presence / absence of scramble will be described with reference to FIG.

  FIG. 17 is a diagram illustrating MMT scramble control bits.

  In the fourth embodiment, the MMT scramble control bit indicating the presence / absence of scramble is stored in the fourth area from the beginning of the extension area (see FIG. 5A).

  When the MMT scramble control bit is 0, there is no scramble, and 1 indicates that the scramble key is scrambled.

  Next, the ECM data structure will be described with reference to FIG.

  FIG. 18 shows the data structure of ECM.

  FIG. 18 shows a part of the ECM-F1 main body in the ECM data structure. In the fourth embodiment, since there is only one type of scramble key, it has a data structure in which items for distinguishing between even keys and odd keys are removed from the ECM structure of the third embodiment shown in FIG.

  Next, processing executed by the receiver 400A will be described with reference to FIG.

  FIG. 19 is a flowchart illustrating processing executed by receiver 400A of the fourth embodiment.

  The receiver 400A starts processing when the power is turned on (start).

  The receiver 400A receives the MMTP packet (step S41).

  The main control unit 401 of the receiver 400A determines whether or not the received MMTP packet includes an ECM (step S42). Whether or not it is an ECM can be determined, for example, by reading a packet ID (packet ID: see FIG. 4) included in the MMTP packet. The packet ID includes information indicating whether the EMM, ECM, broadcast content, or communication content is included in the payload of the MMTP packet.

  When determining that the ECM is the ECM (S42: Yes), the main control unit 401 of the receiver 400A stores the ECM in the data area of the ECM management unit 460 (step S43). When the process of step S43 ends, the main control unit 401 of the receiver 400A ends the flow. Then, the flow is started again.

  If the main control unit 401 of the receiver 400A determines that it is not an ECM (S42: No), it determines whether the content is scrambled broadcast content or communication content (step S44).

  When the main control unit 401 of the receiver 400A determines that the content is scrambled broadcast content or communication content (S44: Yes), the sequence number of the MMTP packet of the broadcast content or communication content scrambled by the content packet analysis unit 480 is set. Extraction (analysis) is performed (step S45). At this time, the content packet analysis unit 480 analyzes the sequence number of the MMTP packet of the broadcast content or communication content input from the ECM packet analysis unit 450 and outputs it to the ECM extraction unit 470.

  The ECM extraction unit 470 refers to the data area of the ECM management unit 460 and extracts an ECM having a sequence number that is the same as the sequence number input from the content packet analysis unit 480 (the value matches) (step S46).

  The main control unit 401 causes the scramble key extraction unit 370 to transmit the ECM extracted in step S46 to the CAS descrambling apparatus 410A (step S47).

  If the main control unit 401 determines in step S44 that the broadcast content or communication content is not scrambled (S44: No), the process is terminated.

  Thus, a series of processing ends. The flow shown in FIG. 19 is executed under the overall control of the main control unit 401, and is executed every time an MMTP packet is received.

  As a result of the above processing, the CAS descrambling apparatus 410A uses the device key Kd to decrypt the EMM input from the content packet analysis unit 480, extracts the work key Kw, and extracts the ECM using the work key Kw. The ECM input from the unit 470 is decrypted to extract the scramble key Ks. Then, CAS descrambling apparatus 410A descrambles the scrambled broadcast content and communication content MMTP packets using scramble key Ks.

  The descrambled MMTP packet of the broadcast content and communication content is output to MMTDEMUX 270.

  The MMT DEMUX 270 outputs the broadcast content and the communication content separately, and the broadcast content and the communication content are combined and presented on the TV screen.

  As described above, according to the fourth embodiment, even if the scramble key is one type with no distinction between the even key and the odd key, one common CAS method used for a plurality of different transmission paths is a hybrid type. In the broadcasting system 3A, a receiver 400A that can output contents in the order of transmission by the transmitter 100B can be provided even when a delay due to a difference in transmission time occurs between different transmission paths. .

  In addition, since the receiver 400A can output contents in the order of transmission by the transmitter 100B, even if the scramble key is one type without distinction between the even key and the odd key, the MMT with reduced data transmission capacity The broadcasting system 3A of the fourth embodiment can be provided.

  As described above, according to the fourth embodiment, even when the scramble key is one type without distinction between the even key and the odd key, the MMT broadcasting system 3A with the reduced data transmission capacity, and the broadcasting system 3A A receiver 400A and a transmitter 100A can be provided.

  The receiver, transmitter, and content receiving method according to the exemplary embodiments of the present invention have been described above. However, the present invention is not limited to the specifically disclosed embodiments, and may be patented. Various modifications and changes can be made without departing from the scope of the claims.

1A Broadcasting System 100A Transmitter 110A Scrambler 140 MMTMUX
150 Separator 200A Receiver 210A CAS Descrambler 240 Synthesizer 250 Receive Buffer 260 MMT Packet Switch 270 MMTDEMUX
2A Broadcast System 300A Receiver 310A CAS Descramble Device 350 ECM Packet Analysis Unit 360 Scramble Key Management Unit 370 Scramble Key Extraction Unit 380 Content Packet Analysis Unit 390 Main Control Unit 3A Broadcast System 100B Transmitter 160 Sequence Number Designation Unit 400A Receiver 401 Main control unit 410A CAS descrambling device 450 ECM packet analysis unit 460 ECM management unit 470 ECM extraction unit 480 Content packet analysis unit

Claims (7)

The scrambled broadcast content and communication content are received from a transmitter that scrambles the broadcast content transmitted by the broadcast wave and the communication content transmitted through the transmission path by wired communication or wireless communication with a scramble key. A receiver,
An association unit that associates the scrambled broadcast content and communication content with the scramble key using a time stamp or an identifier assigned to the broadcast content, the communication content, and the scramble key by the transmitter;
And a descrambling unit that descrambles the scrambled broadcast content and communication content with the scramble key associated by the associating unit.   The associating unit rearranges the scrambled broadcast content and communication content received from the transmitter and the scramble key in time series according to the time stamp, and The receiver according to claim 1, wherein communication contents are associated with the scramble key.   The associating unit, when the time difference between the time stamp of the scrambled broadcast content and communication content received from the transmitter and the time stamp of the scramble key is equal to or less than a predetermined threshold, The receiver according to claim 1, wherein content and communication content are associated with the scramble key. The transmitter assigns the same identifier as the identifier assigned to the broadcast content and the communication content to the scramble key used for scrambling the broadcast content and the communication content,
The associating unit associates the scrambled broadcast content and communication content with the scramble key having the same identifier as the identifier of the scrambled broadcast content and communication content received from the transmitter, The receiver according to claim 1, wherein the scramble key is associated. The scramble key includes an odd key and an even key, and the scrambled broadcast content and communication content are provided with determination data indicating whether the scrambled key is scrambled with the odd key or the even key. And
5. The reception according to claim 2, wherein the descrambling unit descrambles the scrambled broadcast content and communication content using the odd key or the even key corresponding to the discrimination data. Machine. A transmitter that scrambles broadcast content transmitted by a broadcast wave and communication content transmitted through a transmission path by wired communication or wireless communication with a scramble key, and transmits the scrambled key to a receiver.
A transmitter comprising: an identifier assigning unit that assigns the same identifier to broadcast content or communication content scrambled with the scramble key and to the scramble key. The scrambled broadcast content and the communication content are transmitted from a transmitter that scrambles the broadcast content transmitted by a broadcast wave and the communication content transmitted through a transmission path by wired communication or wireless communication with a scramble key. A method of receiving content,
Computer
Associating the broadcast content and the communication content with the scramble key using a time stamp or an identifier assigned to the broadcast content, the communication content, and the scramble key by the transmitter;
A content receiving method, comprising: descrambling the broadcast content and the communication content with the scramble key associated by the association unit.

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