JP7134811B2 - Broadcasting system, receiving device, transmitting device, control method, and program - Google Patents

Description

The present invention relates to a broadcasting system, a receiver, a transmitter, a control method, and a program.

BS digital broadcasting, terrestrial digital broadcasting, 110-degree CS digital broadcasting, and the like send and receive video and audio as digital data, so data is encrypted to prevent unauthorized copying. For this reason, receivers (televisions and tuners) that receive digital broadcasts have an external storage medium called a B-CAS card (BS-Conditional Access System Card) that records information for decrypting (decoding) the code. A certain IC card is attached (enclosed) (for example, Patent Document 1). By attaching this IC card to the receiver, it is possible to view digital broadcasting. In addition, for channels such as pay channels that require individual contracts, it is possible to view the contracted channels by inserting an IC card with which a viewing contract has been made with a broadcaster into the receiver.

JP 2007-208725 A

However, in the conventional system as described in Patent Document 1, viewing was possible only by judging whether the contracted IC card was used. Viewing was possible even when the card was attached to the receiving device. In other words, it was possible to view paid channels by illegally using the IC card.

The present invention has been made in view of the above points, and provides a broadcasting system, a receiving device, a transmitting device, a receiving device, and a transmitting device that prevent digital broadcasting from being viewed on an illegally obtained external storage medium (for example, an IC card). An object is to provide a control method and a program.

The present invention has been made to solve the above problems, and one aspect of the present invention provides a transmission device that transmits an encrypted broadcast signal, and a plurality of receivers that receive the broadcast signal transmitted from the transmission device. , wherein the receiving device includes a receiving unit for receiving an encrypted broadcast signal transmitted from the transmitting device; and information for decrypting the encrypted broadcast signal. A connection unit for connecting a recorded external storage medium, a management unit for managing management information that associates identification information for identifying the receiving device with information recorded on the external storage medium, and the management unit for managing a decryption unit for decrypting an encrypted broadcast signal received by the reception unit based on the management information , wherein the transmission device is configured to decode the encrypted broadcast signal based on the management information managed by the management unit of the reception device. and includes identification information capable of identifying the receiving device and information recorded on the external storage medium for each combination of identification information capable of identifying the receiving device and information recorded on the external storage medium. A key generation unit that generates an encryption key, and an encryption unit that encrypts broadcast data obtained by digitizing a video signal and an audio signal of a broadcast program and multiplexing them with additional information using the encryption key generated by the key generation unit. and a transmission unit that transmits, as the encrypted broadcast signal, a broadcast signal obtained by modulating the broadcast data encrypted by the encryption unit, and transmits the encryption key generated by the key generation unit to the receiving device. , wherein the decoding unit of the receiving device decodes the encrypted broadcast signal received by the receiving unit based on the encryption key transmitted from the transmitting device and the management information managed by the management unit and the transmitting unit stores, in the management information managed by the management units of the plurality of receiving devices , the identification information that can identify the receiving devices that is the same but different from the external storage medium update information of information recorded in different external storage media associated with the same identification information for a plurality of the receiving devices with the same identification information, if the recorded information is associated with the recorded information; is a broadcasting system that transmits

According to another aspect of the present invention , there is provided a receiver that receives a broadcast signal transmitted from a transmitter, comprising: a receiver that receives an encrypted broadcast signal that is transmitted from the transmitter; a connection unit for connecting an external storage medium in which information for decoding a broadcast signal is recorded; and management for managing management information that associates identification information that can identify the receiving device with information recorded in the external storage medium. and a decryption unit that decrypts an encrypted broadcast signal received by the reception unit based on the management information managed by the management unit , wherein the transmission device performs the management of the reception device. identification information capable of identifying the receiving device and the external storage medium for each combination of identification information capable of identifying the receiving device and information recorded in the external storage medium, based on the management information managed by the unit; and a key generation unit for generating an encryption key containing the information recorded in the broadcast program; and a broadcast signal obtained by modulating the broadcast data encrypted by the encryption unit is transmitted as the encrypted broadcast signal, and the encryption key generated by the key generation unit is transmitted as the encrypted broadcast signal. a transmission unit for transmitting to the reception device, the decryption unit, based on the encryption key transmitted from the transmission device and the management information managed by the management unit, decrypts the encrypted data received by the reception unit; The receiving unit decodes the encoded broadcast signal, and the receiving unit determines that the management information managed by the management units of the plurality of receiving devices includes the same identification information that can identify the receiving devices, but different identification information. When the information recorded on the external storage medium is associated with the information, the information recorded on the different external storage medium associated with the same identification information is recorded for the plurality of receiving devices with the same identification information. The receiving device receives update information of the information received from the transmitting device .

According to another aspect of the present invention, there is provided a receiving unit that receives an encrypted broadcast signal, a connection unit that connects an external storage medium in which information for decoding the encrypted broadcast signal is recorded, and a self-receiving device. a management unit that manages management information that associates identification information that can identify the external storage medium with information recorded in the external storage medium; and encryption received by the reception unit based on the management information managed by the management unit a transmitting device for transmitting a broadcast signal to a receiving device, the transmitting device comprising: a decoding unit for decoding the received broadcast signal ; A key generation unit that generates an encryption key containing identification information that can identify a receiving device and information recorded in the external storage medium, and a video signal and an audio signal of a broadcast program that are digitized and multiplexed with additional information. An encryption unit for encrypting broadcast data using an encryption key generated by the key generation unit; a transmission unit that transmits the encryption key generated by the key generation unit as a signal and transmits the encryption key generated by the key generation unit to the reception device , wherein the transmission unit is the management unit managed by the management units of the plurality of reception devices If the information contains the same identification information that can identify the receiving device and is associated with information recorded in different external storage media, the plurality of the receiving devices with the same identification information On the other hand, the transmission device transmits update information of information recorded in different external storage media associated with the same identification information .

According to another aspect of the present invention, there is provided a control method in a broadcasting system including a transmission device that transmits an encrypted broadcast signal and a plurality of reception devices that receive the broadcast signal transmitted from the transmission device , A receiving device having a connection unit for connecting an external storage medium in which information for deciphering the encrypted broadcast signal is recorded, the receiving unit receiving the encrypted broadcast signal transmitted from the transmitting device a receiving step, a management step in which a management unit manages management information that associates identification information that can identify the receiving device with information recorded in the external storage medium, and a decoding unit that is managed by the management unit and a decryption step of decrypting the encrypted broadcast signal received by the receiving unit based on the management information , wherein the transmitting device is managed by the key generation unit and the management unit of the receiving device. identification information capable of identifying the receiving device and information recorded on the external storage medium for each combination of identification information capable of identifying the receiving device and information recorded on the external storage medium based on the management information; a generation step of generating an encryption key containing information; and an encryption unit digitizes a video signal and an audio signal of a broadcast program and multiplexes the broadcast data with additional information with the encryption key generated by the key generation unit. a transmission unit transmitting, as the encrypted broadcast signal, a broadcast signal obtained by modulating the broadcast data encrypted by the encryption unit, and the key generation unit generates and a transmission step of transmitting the encrypted key to the receiving device, and in the decoding step, the receiving unit based on the encryption key transmitted from the transmitting device and the management information managed by the management unit decrypts the encrypted broadcast signal received by the transmitting device, and the transmitting device identifies the receiving device in the management information managed by the management units of the plurality of receiving devices If there are devices that have the same possible identification information and are associated with information recorded in different external storage media, the plurality of receiving devices with the same identification information are associated with the same identification information. a transmission step of transmitting update information of information recorded in the different external storage media .

Another aspect of the present invention is a control method for a receiving device including a connection unit for connecting an external storage medium in which information for decoding an encrypted broadcast signal is recorded, wherein the receiving unit transmits a broadcast signal. a receiving step of receiving an encrypted broadcast signal transmitted from a transmitting device; and a decryption step in which a decryption unit decrypts an encrypted broadcast signal received by the reception unit based on the management information managed by the management unit , wherein the transmission device comprises , the receiving device can be identified for each combination of identification information that can identify the receiving device and information recorded in the external storage medium, based on the management information managed by the management unit of the receiving device a key generation unit for generating an encryption key containing identification information and information recorded in the external storage medium; an encryption unit that performs encryption using the encryption key generated by the generation unit; a broadcast signal obtained by modulating the broadcast data encrypted by the encryption unit is transmitted as the encrypted broadcast signal; a transmitting unit configured to transmit the encryption key generated by the unit to the receiving device, and the decrypting unit stores the encryption key transmitted from the transmitting device and the management information managed by the management unit in the decrypting step. and decrypts the encrypted broadcast signal received by the receiving unit based on is associated with information recorded in different external storage media, the same identification information is used for a plurality of the receiving devices with the same identification information. The control method further comprises a receiving step of receiving update information of information recorded in the associated different external storage media from the transmitting device .

According to another aspect of the present invention, there is provided a receiving unit that receives an encrypted broadcast signal, a connection unit that connects an external storage medium in which information for decoding the encrypted broadcast signal is recorded, and a self-receiving device. a management unit that manages management information that associates identification information that can identify the external storage medium with information recorded in the external storage medium; and encryption received by the reception unit based on the management information managed by the management unit A control method in a transmitting device for transmitting a broadcast signal to a receiving device, the method comprising: a decoding unit that decodes a broadcast signal that has been decoded; a key generation step of generating an encryption key containing identification information that can identify the receiving device and information recorded in the external storage medium for each combination with information; and an encryption step of encrypting broadcast data obtained by digitizing an audio signal and multiplexing it with additional information using an encryption key generated by the key generation unit; a transmitting step of transmitting , as the encrypted broadcast signal, a broadcast signal obtained by modulating the broadcast data, and transmitting an encryption key generated by the key generating unit to the receiving device ; When the management information managed by the management unit of the device contains information that has the same identification information that can identify the receiving device but is associated with information recorded on different external storage media. and a transmission step of transmitting update information of information recorded in different external storage media associated with the same identification information to a plurality of the receiving devices having the same identification information. .

Further, according to one aspect of the present invention, an encrypted broadcast signal is transmitted from a transmission device that transmits a broadcast signal to a computer as a reception device that includes a connection unit that connects an external storage medium in which information for decoding the broadcast signal is recorded. a receiving step of receiving an encrypted broadcast signal; a managing step of managing management information that associates identification information that can identify the receiving device with information recorded on the external storage medium; and a decryption step of decrypting the encrypted broadcast signal received in the reception step, and the transmission device performs the reception based on the management information managed by the management step of the reception device. generating an encryption key containing identification information capable of identifying the receiving device and information recorded in the external storage medium for each combination of the identification information capable of identifying the device and the information recorded in the external storage medium; an encryption unit for encrypting broadcast data obtained by digitizing a video signal and an audio signal of a broadcast program and multiplexing them with additional information using an encryption key generated by the key generation unit; a transmission unit that transmits a broadcast signal obtained by modulating broadcast data encrypted by the encryption unit as the encrypted broadcast signal, and transmits an encryption key generated by the key generation unit to the receiving device; In the decryption step, the encrypted broadcast signal received in the reception step is decrypted based on the encryption key transmitted from the transmission device and the management information managed in the management step, and a plurality of the reception When the management information managed by the management step of the device includes information that has the same identification information that can identify the receiving device but is associated with information recorded in different external storage media. and a receiving step of receiving update information of information recorded in different external storage media associated with the same identification information from the transmitting device for the plurality of the receiving devices having the same identification information . It is a program for

According to another aspect of the present invention, there is provided a receiving unit that receives an encrypted broadcast signal, a connection unit that connects an external storage medium in which information for decoding the encrypted broadcast signal is recorded, and a self-receiving device. a management unit that manages management information that associates identification information that can identify the external storage medium with information recorded in the external storage medium; and encryption received by the reception unit based on the management information managed by the management unit For each combination of identification information that can identify the receiving device and information recorded on the external storage medium , A key generation step of generating an encryption key containing identification information that can identify the receiving device and information recorded in the external storage medium, and a video signal and audio signal of a broadcast program are digitized and multiplexed with additional information an encryption step of encrypting the broadcast data encrypted by using the encryption key generated in the key generation step; and a broadcast signal obtained by modulating the broadcast data encrypted in the encryption step to the encrypted broadcast signal. and a transmission step of transmitting the encryption key generated in the key generation step to the receiving device; When there are devices that have the same identifiable identification information and are associated with information recorded in different external storage media, the plurality of receiving devices with the same identification information are associated with the same identification information. and a transmitting step of transmitting update information of information recorded in the different external storage medium .

According to the present invention, it is possible to prevent digital broadcasts from being viewed using an illegally obtained external storage medium (for example, an IC card).

1 is a system diagram showing an example of a broadcasting system according to an embodiment; FIG. 1 is a block diagram showing an example of the configuration of a transmission device according to an embodiment; FIG. 1 is a block diagram showing a first example of the configuration of a receiver according to an embodiment; FIG. The block diagram which shows the 2nd example of a structure of the receiving apparatus which concerns on embodiment. 4 is a flowchart showing an example of encryption key generation processing according to the embodiment; 4 is a flowchart showing an example of decryption processing (decryption processing) according to the embodiment;

An embodiment of the present invention will be described below with reference to the drawings.
[Overview of Broadcast System 10]
FIG. 1 is a system diagram showing an example of a broadcasting system according to this embodiment. The illustrated broadcasting system 10 includes a transmitting device 100 of a broadcaster (broadcasting station) that broadcasts broadcast programs such as BS digital broadcasting, terrestrial digital broadcasting, and 110-degree CS digital broadcasting, and transmission (broadcasting) from the transmitting device 100. It includes receivers 200 (200A, 200B) that receive broadcast signals. Broadcast system 10 is a conditional access system that provides broadcast programs only to specific viewers. The transmission device 100 transmits, from the broadcast antenna 30, a broadcast signal obtained by encrypting digital data of video and audio to be broadcast. Broadcast signals of satellite broadcasting (BS digital broadcasting, 110-degree CS digital broadcasting, etc.) among broadcasting signals transmitted from transmitting device 100 are sent to receiving antenna 50 on the receiving side via broadcasting satellite 40 . A broadcast signal transmitted from the transmitting device 100 is received by the receiving device 200 (200A, 200B) via the receiving antenna 50 of the receiving side (for example, each home). Note that the transmission device 100 may broadcast a new 4K8K satellite broadcast program.

The receiving device 200 (200A, 200B) receives the broadcast signal transmitted from the transmitting device 100 via the receiving antenna 50, demodulates and decodes (decrypts) the received broadcast signal, and converts it into a viewable video and audio signal. to generate Here, the receiving device 200A is a television device (television) that receives and displays broadcast signals. On the other hand, the receiving device 200B is a tuner (so-called STB: Set Top Box) that receives broadcast signals and outputs video and audio signals to an externally connected display device. For example, a broadcast signal received via the receiving antenna 50 is sent via the cable 4 to the receiving device 200A, and further sent from the receiving device 200A via the cable 5 to the receiving device 200B. The receiving device 200A displays the video and audio signals generated from the received broadcast signal so that they can be viewed. The receiving device 200A is also configured as a display device for the receiving device 200B, receives video and audio signals output from the receiving device 200B via the cable 6, and displays the input video and audio signals. Note that the illustrated connection example of the receiving device 200A and the receiving device 200B is an example, and is not limited to this. Hereinafter, when the receiver 200A and the receiver 200B are not particularly distinguished, they are simply referred to as the receiver 200. FIG.

In the broadcasting system 10 according to the present embodiment, an IC card (hereinafter referred to as a B-CAS card (BS-Conditional Access System Card)), which is an external storage medium in which information necessary for deciphering (decoding) is recorded. (referred to as a “CAS card”) is attached to the receiving device 200 . In addition, the receiving device 200 associates and manages information (eg, card number) recorded on the attached CAS card and identification information (eg, device ID) that can uniquely identify the receiving device 200 . For example, the receiving device 200A associates and manages the card number of the CAS card (CAS1) attached to the receiving device 200A and the device ID of the receiving device 200A. The receiving device 200B associates and manages the card number of the CAS card (CAS2) attached to the receiving device 200B and the device ID of the receiving device 200B.

The transmitting device 100 generates an encryption key (key data) based on the card number and device ID associated with the receiving device 200 . For example, the transmitting device 100 generates an encryption key containing the card number and device ID associated with each receiving device 200 . As an example, the transmitting device 100 generates an encryption key including a combination of the card number of the CAS card (CAS1) attached to the receiving device 200A and the device ID of the receiving device 200A. Also, the transmitting device 100 generates an encryption key including a combination of the card number of the CAS card (CAS2) attached to the receiving device 200B and the device ID of the receiving device 200B. The transmitting device 100 transmits the broadcast signal encrypted using the generated encryption key. As a result, in the broadcasting system 10 , it is possible to decode (decrypt) the broadcast signal only by combining the card number and the device ID managed by the receiving device 200 . Therefore, it is possible to view a broadcast program only when a regular CAS card is attached to the receiver 200, and it is possible to prevent digital broadcasting from being viewed with an illegally obtained CAS card. A specific configuration of this embodiment will be described below.

[Structure of transmitter]
The configuration of the transmission device 100 according to the present embodiment will be described with reference to FIG.
FIG. 2 is a block diagram showing an example of the configuration of the transmission device 100 according to this embodiment. The transmission device 100 includes a transmission signal processing section 110 , an encryption section 120 and a control section 130 . The transmission signal processing unit 110 includes a video/audio encoding unit 111, a video/audio synchronization control unit 112, a buffer unit 113, a packetization unit 114, an SI generation/packetization unit 115, a multiplexing unit 116, A modulation section 117 and a transmission section 118 are provided.

A video signal and an audio signal of a broadcast program are input to the video/audio encoding unit 111 . The video/audio encoding unit 111 converts the input video signal and audio signal into digital video data and audio data, and supplies the digital video data and audio data to the buffer unit 113 . The video/audio synchronization control unit 112 controls synchronization of video data and audio data.

The video data and audio data supplied to the buffer unit 113 are packetized by the packetization unit 114 . Current broadcasting (BS digital broadcasting, terrestrial digital broadcasting, 110-degree CS digital broadcasting, etc.) is packetized in the MPEG-2 TS (Transport Stream) format. In the new 4K8K satellite broadcasting, packetization is performed by the MMT (MPEG Media Transport)-TLV (Type Length Value) method.

The SI generation/packetization unit 115 generates additional information such as program sequence information and packetizes it. For example, when transmitting an MPEG-2 TS broadcast signal, the SI generator/packetizer 115 generates SI (Service Information) and packetizes it. When transmitting an MMT-TLV broadcast signal, SI generation/packetization section 115 generates and packetizes MMT-SI (Signaling Information).

The multiplexing unit 116 multiplexes packetized SI (or MMT-SI) data, packetized TS (or TLV) data, etc. in MPEG-2 TS format (or MMT-TLV format). . The multiplexed broadcast data is encrypted by encryption section 120 and supplied to modulation section 117 . The modulation unit 117 modulates the encrypted broadcast data according to the broadcast signal standard. Transmitter 118 transmits the broadcast signal modulated by modulator 117 via broadcast antenna 30 .

The encryption unit 120 has a CAS management unit 121 and a CAS scrambler 122 . The CAS management unit 121 manages the device ID of the receiving device 200 and the card number of the CAS card attached (packaged) to the receiving device 200 in association with each other. That is, the CAS management unit 121 manages the device ID of the receiving device 200 and the card number of the CAS card to be attached to the receiving device 200 in association with each other. For example, the CAS management unit 121 associates and stores the card number and the device ID in a memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory). Note that the CAS management unit 121 may acquire the association information between the device ID of the receiving device 200 and the card number of the CAS card by transmission from the receiving device 200, or may be registered when the user makes a viewing contract. may be obtained from the contract information

Also, the CAS management unit 121 manages the encryption key generated by the control unit 130 based on the association information between the card number and the device ID. For example, the CAS management unit 121 associates the encryption key generated by the control unit 130 with the card number or device ID and stores it in a memory such as an EEPROM.

CAS scrambler 122 performs processing for encrypting a broadcast program and transmitting it from transmitter 118 . For example, the CAS scrambler 122 encrypts the broadcast data multiplexed by the multiplexer 116 using an encryption key managed by the CAS manager 121 and supplies the encrypted data to the modulator 117 .

The control unit 130 generates an encryption key based on the association information between the card number and the device ID managed by the CAS management unit 121 . For example, the control unit 130 generates an encryption key containing the device ID of each receiving device 200 and the card number of the CAS card attached (enclosed) to each receiving device 200 . The control unit 130 supplies the generated encryption key to the CAS management unit 121 .

The encryption key generated by the control unit 130 based on the association information between the card number and the device ID is a key (master key) uniquely set for each CAS card for encrypting an EMM (Entitlement Management Message). or a key for encrypting an ECM (Entitlement Control Message) (work key: a key included in an EMM and transmitted). Also, the encryption key may be a key (scramble key) for encrypting video and audio data of a broadcast program.

Further, the encryption process is not limited to after multiplexing, and may be performed before multiplexing. Also, some encryption operations may be performed before multiplexing and the remaining encryption operations may be performed after multiplexing.

[Configuration of Receiving Device]
Next, the configuration of the receiving apparatus 200 according to this embodiment will be described with reference to FIGS. 3 and 4. FIG.
FIG. 3 is a block diagram showing an example of the configuration of the receiving device 200A according to this embodiment. The receiving device 200A is a television device (television) as described above. Further, the receiving device 200A is compatible with reception of current broadcasting (BS digital broadcasting, terrestrial digital broadcasting, 110-degree CS digital broadcasting, etc.).

The receiving device 200A includes a receiving section 210A, a received signal processing section 220A, a CAS processing section 230A, a control section 240A, and an output section 250A. The output section 250A includes a display section 251A and a speaker 252A. The display unit 251A includes a liquid crystal display, an organic EL (Electro Luminescence) display, and the like, and displays an image based on an input image signal. Speaker 252A outputs sound based on an input audio signal.

The receiving section 210A includes a tuner section 211A and a demodulator 212A. The tuner unit 211A receives broadcast signals such as BS digital broadcast, terrestrial digital broadcast, and 110-degree CS digital broadcast via the receiving antenna 50 . The receiving antenna 50 is a parabolic antenna for receiving broadcasting signals of satellite broadcasting such as BS digital broadcasting and 110-degree CS digital broadcasting, and a UHF antenna for receiving broadcasting signals of terrestrial digital broadcasting.

The tuner unit 211A selects and receives the broadcast signal of the channel selected by the user under the control of the control unit 240A, and supplies the received signal to the demodulator 212A. The demodulator 212A demodulates the received signal and supplies TS data to the received signal processing section 220A.

The reception signal processing section 220A includes a demultiplexer 221A, an SI analysis section 222A, an AV control section 223A, a packet analysis section 224A, a buffer section 225A, and an AV decoding section 226A.

The TS data supplied from the demodulator 212A to the received signal processor 220A is separated by the demultiplexer 221A into video and audio data and additional information (such as SI) such as program arrangement information. The video and audio data are supplied to the packet analysis unit 224A, and the additional information is supplied to the SI analysis unit 222A.

The SI analysis unit 222A extracts various types of information (such as SI) included in the additional information. The SI analysis unit 222A supplies the extracted information to the AV control unit 223A, which is used for information displayed instead of or superimposed on the video data (time information, program arrangement information, etc.). The SI analysis unit 222A also extracts an ECM (Entitlement Control Message) and an EMM (Entitlement Management Message) from the SI, and supplies them to the CAS processing unit 230A or the control unit 240A.

Based on the information (time information, program arrangement information, etc.) supplied from the SI analysis unit 222A, the AV control unit 223A displays information (time information, electronic program guide, etc.) instead of or superimposed on the video data. is generated and supplied to the AV decoding unit 226A.

The packet analysis unit 224A obtains the packet length of the data portion of the video and audio data from the TS data (packet data), and supplies the video and audio data to the buffer unit 225A.

The video and audio data supplied to the buffer unit 225A is decrypted (decrypted) by the processing of the CAS processing unit 230A and supplied to the AV decoding unit 226A.

The AV decoding unit 226A decodes the supplied video and audio data into a video signal and an audio signal that can be output to the display unit 251A and the speaker 252A. The AV decoding unit 226A outputs the decoded video signal to the display unit 251A. Also, the AV decoding unit 226A outputs the decoded audio signal to the speaker 252A. In addition, the AV decoding unit 226A outputs the supplied time information, electronic program guide, etc. as a video signal according to predetermined conditions (user's operation, predetermined timing, etc.).

The CAS processing section 230A includes a card insertion section 231A, a CAS management section 232A, and a CAS descrambling section 233A. The card insertion portion 231A is a connection portion for connecting a CAS card (an example of an external storage medium). A CAS card is inserted into the card insertion part 231A, and information is transmitted/received to/from the inserted CAS card. A CAS card has a unique card number, a unique master key, and the like registered for each card. In addition, in the CAS card, when a viewing contract for pay broadcasting or the like is made, personal contract information regarding the contract is registered. When viewing broadcast programs such as BS digital broadcasting, terrestrial digital broadcasting, and 110-degree CS digital broadcasting with the receiving device 200A, the CAS card (CAS1) that was attached (included) when the receiving device 200A was purchased is required. Must be installed.

The CAS management unit 232A acquires information on the CAS card (CAS1) attached to the card insertion unit 231A, and manages the card number of the CAS card and the device ID of the receiving device 200A in association with each other. For example, the CAS management unit 232A associates and stores the card number of the CAS card inserted in the card insertion unit 231A and the device ID of the receiving device 200A in a memory such as an EEPROM.

The CAS descrambling unit 233A decrypts (decrypts) the video and audio data supplied from the packet analysis unit 224A to the buffer unit 225A using the encryption key. For example, the CAS descrambling unit 233A decrypts the EMM extracted by the SI analysis unit 222A using a master key uniquely set for each CAS card. Next, the CAS descrambling unit 233A extracts a work key for decrypting the ECM from the decrypted EMM. The CAS descrambling unit 233A decrypts the ECM using the extracted work key, and extracts a scramble key for decrypting the video and audio data from the decrypted ECM. The CAS descrambler 233A then decodes the video and audio data using the extracted scramble key.

Here, CAS descrambler 233A performs the is decrypted, and if it does not match, it is not decrypted.

For example, if the encryption key generated by transmitting device 100 based on the association information between the card number and the device ID is the master key, CAS descrambler 233A determines that the card number and device ID included in the master key are , the EMM is decoded if it matches the card number of the CAS card loaded in the card insertion portion 231A and the device ID of the receiving device 200A, and the EMM is not decoded if they do not match. When the EMM is decrypted, the CAS descrambling unit 233A extracts the work key as described above, decrypts the ECM using the extracted work key, and extracts the scramble key. The CAS descrambler 233A then decodes the video and audio data using the extracted scramble key. On the other hand, if the EMM is not decrypted, the CAS descrambling unit 233A cannot extract the work key nor the scrambling key, so it does not decrypt the video and audio data.

Further, when the encryption key generated based on the association information between the card number and the device ID in transmitting device 100 is the work key extracted from the EMM, CAS descrambler 233A descrambles the card number included in the work key. and the device ID matches the card number of the CAS card attached to the card insertion unit 231A and the device ID of the receiving device 200A, the work key is used to decrypt the ECM, and if they do not match, the ECM is decrypted. do not do. When the ECM is decoded, the CAS descrambler 233A extracts a scramble key for decoding video and audio data from the ECM, and decodes the video and audio data using the extracted scramble key. On the other hand, if the ECM is not decrypted, the CAS descrambling unit 233A cannot extract the scramble key, so it does not decrypt the video and audio data.

Further, when the encryption key generated based on the association information between the card number and the device ID in transmitting device 100 is the scramble key extracted from the ECM, CAS descrambler 233A descrambles the card number included in the scramble key. and the device ID matches the card number of the CAS card attached to the card insertion unit 231A and the device ID of the receiving device 200A, the scramble key is used to decrypt the video and audio data; Do not decode video and audio data.

In this way, the CAS descrambling unit 233A decrypts the video and audio data and makes them viewable only when the combination of the receiving device 200A and the CAS card attached to the receiving device 200A is legitimate.

Here, the determination of the card number and the device ID is performed by the control section 240A. For example, the control unit 240A acquires the encryption key transmitted from the transmission device 100 and the card number and device ID associated with the CAS management unit 232A. Then, the control unit 240A extracts the card number and device ID included in the encryption key, compares them with the card number and device ID associated with the CAS management unit 232A, and determines whether or not they match. If the card number and device ID included in the encryption key match the card number and device ID associated with the CAS management unit 232A, the control unit 240A permits the CAS descrambler 233A to perform the decryption process. do. On the other hand, if the card number and device ID included in the encryption key do not match the card number and device ID associated with the CAS management unit 232A, the control unit 240A permits the CAS descrambler 233A to perform the decryption process. Do not (prohibit).

Also, the control unit 240A supplies information indicating the channel selected by the user's operation to the tuner unit 211A. Thereby, the tuner section 211A receives the broadcast signal of the channel selected by the user. In addition, the control unit 240A performs control such as displaying various setting screens, an electronic program guide, etc. on the display unit 251A by user's operation.

FIG. 4 is a block diagram showing an example of the configuration of the receiving device 200B according to this embodiment. The receiving device 200B is a tuner (so-called STB: Set Top Box) as described above. For example, the receiving device 200B is a tuner that receives broadcast signals compatible with the MMT-TLV system. The receiver 200B includes a receiver 210B, a received signal processor 220B, a CAS processor 230B, and a controller 240B. The receiving section 210B includes a tuner section 211B and a demodulator 212B. The tuner unit 211B receives, via the receiving antenna 50, broadcast signals of broadcasting (for example, new 4K8K satellite broadcasting) compatible with the MMT-TLV system. For example, the receiving antenna 50 is an antenna compatible with new 4K8K satellite broadcasting. The tuner section 211B selects and receives the broadcast signal of the channel selected by the user under the control of the control section 240A, and supplies the received signal to the demodulator 212B. The demodulator 212B demodulates the received signal and supplies TLV data to the received signal processor 220B.

The reception signal processing section 220B includes a demultiplexer 221B, an MMT-SI analysis section 222B, an AV control section 223B, an MPU/MMT packet analysis section 224B, a buffer section 225B, and an AV decoding section 226B.

The TLV data supplied from the demodulator 212B to the received signal processing unit 220B is demultiplexed by the demultiplexer 221B into MPU (Media Processing Unit)/MMT packet data and additional information (such as MMT-SI) such as program sequence information. be. The MPU/MMT packet data is supplied to the MPU/MMT packet analysis unit 224B, and the additional information is supplied to the MMT-SI analysis unit 222B.

MMT-SI analysis section 222B extracts various types of information (MMT-SI, etc.) included in the additional information. Of the extracted information, the MMT-SI analysis section 222B supplies information (time information, program arrangement information, etc.) used for information displayed instead of or superimposed on the video data to the AV control section 223B. Also, the MMT-SI analysis unit 222B extracts the ECM and EMM from the MMT-SI and supplies them to the CAS processing unit 230B or the control unit 240B.

Based on the information (time information, program sequence information, etc.) supplied from the MMT-SI analysis unit 222B, the AV control unit 223B displays information (time information, electronic program guide, etc.) instead of or superimposed on the video data. etc.) and supplies it to the AV decoding unit 226B.

The packet analysis unit 224B obtains the packet lengths of the data portions of the video and audio data from the MPU/MMT packet data, and supplies the video and audio data to the buffer unit 225B.

The video and audio data supplied to the buffer unit 225B are decrypted (decrypted) by the processing of the CAS processing unit 230B and supplied to the AV decoding unit 226B.

The AV decoding unit 226B decodes the supplied video and audio data into a video signal and an audio signal that can be output from the AV output terminal. For example, the AV output terminal is an HDMI (registered trademark: High-Definition Multimedia Interface) terminal or the like. Also, the AV decoding unit 226B decodes the supplied time information, electronic program guide, etc. into video signals according to predetermined conditions (user's operation, predetermined timing, etc.).

The CAS processing section 230B includes a card insertion section 231B, a CAS management section 232B, and a CAS descrambling section 233B. The basic configurations of the card insertion unit 231B, the CAS management unit 232B, and the CAS descrambler 233B are similar to the card insertion unit 231A, the CAS management unit 232A, and the CAS descrambler 233A shown in FIG. It has the same configuration as each. For example, the CAS management unit 232B acquires information on the CAS card (CAS2) attached to the card insertion unit 231B, and manages the card number of the CAS card and the device ID of the receiving device 200B in association with each other.

The CAS descrambling unit 233B decrypts (decrypts) the video and audio data supplied from the packet analysis unit 224B to the buffer unit 225B using the encryption key. For example, the CAS descrambling unit 233B decrypts the EMM extracted by the MMT-SI analysis unit 222B using a master key uniquely set for each CAS card, and extracts a work key for decrypting the ECM. . The CAS descrambling unit 233B decrypts the ECM using the extracted work key, and extracts a scramble key for decrypting the video and audio data from the decrypted ECM. Then, the CAS descrambler 233B uses the extracted scramble key to decode the video and audio data. Here, CAS descrambler 233B performs the is decrypted, and if it does not match, it is not decrypted.

In this manner, CAS descrambling section 233B decrypts video and audio data to make them viewable only when the combination of receiving device 200B and the CAS card attached to receiving device 200B is legitimate.

The control unit 240B acquires the encryption key transmitted from the transmission device 100 and the card number and device ID associated with the CAS management unit 232B. Then, the control unit 240B extracts the card number and device ID included in the encryption key, compares them with the card number and device ID associated with the CAS management unit 232B, and determines whether or not they match. If the card number and device ID included in the encryption key match the card number and device ID associated with the CAS management unit 232B, the control unit 240B permits the CAS descrambler 233B to perform the decryption process. do. On the other hand, if the card number and device ID included in the encryption key do not match the card number and device ID associated with the CAS management unit 232B, the control unit 240B permits the CAS descrambler 233B to perform the decryption process. Do not (prohibit).

Also, the control section 240B supplies information indicating the channel selected by the user's operation to the tuner section 211B. Thereby, the tuner section 211B receives the broadcast signal of the channel selected by the user. In addition, the control unit 240B performs control such as outputting video signals such as various setting screens and an electronic program guide from the AV output terminal by user's operation.

If the device IDs managed by the CAS management units 232A and 232B transmitted as the contract information from the receiving device 200 are the same, the transmitting device 100 associates them with the same device ID, and performs the association. The updated information of the device ID and the card number of the CAS card may be transmitted to a plurality of CAS card numbers of the receiving device 200 having the same device ID.

[Encryption key generation process]
Next, with reference to FIG. 5, the operation of the encryption key generation process executed by the transmission device 100 will be described. FIG. 5 is a flowchart showing an example of encryption key generation processing according to this embodiment.

(Step S<b>101 ) The transmitting device 100 acquires the association information between the device ID of the receiving device 200 and the card number of the CAS card attached (enclosed) to the receiving device 200 . The transmitting device 100 saves the obtained association information between the device ID and the card number, and proceeds to the process of step S103.

(Step S103) The transmitting device 100 generates an encryption key based on the obtained association information between the device ID and the card number. For example, the transmitting device 100 generates an encryption key containing the acquired device ID and card number. Then, the process proceeds to step S105.

(Step S<b>105 ) The transmitting device 100 transmits the generated encryption key to the receiving device 200 . For example, transmitting device 100 transmits a broadcast signal including the generated encryption key.

[Decryption process (Decryption process)]
Next, the operation of decryption processing (decryption processing) executed by the receiving device 200 will be described with reference to FIG. FIG. 6 is a flowchart showing an example of decryption processing (decryption processing) according to this embodiment.

(Step S<b>201 ) The receiving device 200 acquires the encryption key included in the broadcast signal transmitted from the transmitting device 100 . Then, the process proceeds to step S203.

(Step S203) The receiving device 200 extracts the card number of the CAS card and the device ID of the receiving device 200 from the acquired encryption key. Then, the process proceeds to step S205.

(Step S205) The receiving device 200 compares the extracted card number and device ID with the card number and device ID associated and managed by this receiving device 200, and determines whether or not they match. If it is determined that they match (YES), the process proceeds to step S207.

(Step S207) The receiving device 200 decrypts (decrypts) the video and audio data using the acquired encryption key or the like, and ends the process.

On the other hand, if it is determined in step S205 that they do not match (NO), the receiving device 200 ends the process without performing the decryption (decryption) process in step S207.

As described above, the broadcasting system 10 according to this embodiment includes the transmitting device 100 and the receiving device 200 . The transmission device 100 has a transmission section 118 that transmits an encrypted broadcast signal. The receiving device 200 includes a receiving section 210A (210B), a card insertion section 231A (231B), a CAS management section 232A (232B), and a CAS descrambling section 233A (233B). The receiver 210A (210B) receives the broadcast signal transmitted from the transmitter 100. FIG. The card insertion section 231A (231B) (an example of a connection section) connects a CAS card (an example of an external storage medium) in which information for decoding an encrypted broadcast signal is recorded. The CAS management unit 232A (232B) associates the device ID of the receiving device 200 (an example of identification information that can identify the receiving device 200) with the card number of the CAS card (an example of information recorded in an IC card). Manage information (an example of management information). The CAS descrambling unit 233A (233B) is an example of a decoding unit that decodes the encrypted broadcast signal received by the receiving unit 210A (210B) based on the association information managed by the CAS management unit 232A (232B). .

As a result, in the broadcasting system 10, the receiving device 200 receives the encrypted broadcast signal transmitted from the transmitting device 100 based on the device ID of the receiving device 200 and the card number of the CAS card attached to the receiving device 200. to decrypt. Therefore, the receiving device 200 can decrypt the broadcast signal and make it viewable only when the combination of the receiving device 200 and the CAS card is legitimate. Therefore, the broadcasting system 10 can prevent the digital broadcasting from being viewed with a CAS card of another receiving device 200 or an illegally obtained CAS card.

Also, the CAS descrambler 233A (233B) combines the device ID of the receiving device 200 (an example of identification information with which the receiving device 200 can be identified) and the card number of the CAS card (an example of information recorded on the IC card). The encryption key generated based on the combination is used to decrypt the encrypted broadcast signal received by the receiver 210A (210B).

As a result, the receiving device 200 converts the encrypted broadcast signal transmitted from the transmitting device 100 into a cipher generated based on the device ID of the receiving device 200 and the card number of the CAS card attached to the receiving device 200. Since the key is used for decryption, the encrypted broadcast signal can be decrypted only when the combination of the receiving device 200 and the CAS card is legitimate.

For example, the transmission device 100 includes a control section 130 (an example of a key generation section) and a CAS scramble section 122 (an example of an encryption section). Based on the association information (an example of management information) managed by the CAS management unit 232A (232B) of the reception device 200, the control unit 130 controls the device ID of the reception device 200 (an example of identification information that can identify the reception device 200). ) and the card number of the CAS card (an example of information recorded in the IC card), an encryption key is generated for each combination. CAS scrambler 122 encrypts the broadcast signal using the encryption key generated by controller 130 . Further, the transmitting unit 118 of the transmitting device 100 transmits the encrypted broadcast signal and also transmits the encryption key generated by the control unit 130 to the receiving device 200 . The CAS descrambler 233A (233B) of the receiver 200 determines whether the receiver 210A (210B) can Decrypt the received encrypted broadcast signal.

As a result, since transmitting device 100 encrypts the broadcast signal using an encryption key based on the device ID of receiving device 200 and the card number of the CAS card attached to receiving device 200, receiving device 200 and the CAS card are encrypted. It can be made viewable only when the combination with is legitimate.

A part of the functions of the transmitting device 100 or the receiving device 200 in the above-described embodiments may be realized by a computer. In that case, a program for realizing this function may be recorded in a computer-readable recording medium, and the program recorded in this recording medium may be read into a computer system and executed. The “computer system” referred to here is a computer system built in the transmitting device 100 or the receiving device 200, and includes hardware such as an OS and peripheral devices. The term "computer-readable recording medium" refers to portable media such as flexible discs, magneto-optical discs, ROMs and CD-ROMs, and storage devices such as hard discs incorporated in computer systems. Furthermore, "computer-readable recording medium" means a medium that dynamically stores a program for a short period of time, such as a communication line for transmitting a program via a network such as the Internet or a communication line such as a telephone line. In that case, it may also include a memory that holds the program for a certain period of time, such as a volatile memory inside a computer system that serves as a server or client. Further, the program may be for realizing part of the functions described above, or may be capable of realizing the functions described above in combination with a program already recorded in the computer system.

Also, part or all of the transmitting device 100 or the receiving device 200 may be implemented as an integrated circuit such as an LSI (Large Scale Integration). Also, each component in the transmitting device 100 or the receiving device 200 of this embodiment may be individually processorized, or part or all may be integrated and processorized. Also, the method of circuit integration is not limited to LSI, but may be realized by a dedicated circuit or a general-purpose processor. In addition, when an integration circuit technology that replaces LSI appears due to advances in semiconductor technology, an integrated circuit based on this technology may be used.

In the above embodiment, an IC card such as a CAS card was used as an example of an external storage medium for decoding encrypted broadcast signals. good too.

Further, in the above-described embodiment, the configuration example of the receiving device 200 is a television device or a tuner (so-called STB: Set Top Box), but it is not limited to this. For example, the receiving device 200 may be a hard disk recorder capable of receiving, recording, and playing back television broadcasts, a Blu-ray (registered trademark) recorder, a DVD recorder, or a combination thereof.

Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design changes, etc., can be made without departing from the gist of the present invention. It is possible to

10 broadcasting system, 30 broadcasting antenna, 40 broadcasting satellite, 50 receiving antenna, 100 transmitting device, 110 transmission signal processing unit, 111 video/audio encoding unit, 112 video/audio synchronization control unit, 113 buffer unit, 114 packetizing unit, 115 SI generation/packetization unit 116 multiplexing unit 117 modulation unit 118 transmission unit 120 encryption unit 121 CAS management unit 122 CAS scrambler 130 control unit 200 (200A, 200B) receiver 210A , 210B receiving unit, 211A, 211B tuner unit, 212A, 212B demodulator, 220A, 220B received signal processing unit, 221A, 221B demultiplexer, 222A SI analysis unit, 222B MMT-SI analysis unit, 223A, 223B AV control unit, 224A packet analysis unit, 224B MPU/MMT packet analysis unit, 225A, 225B buffer unit, 226A, 226B AV decoding unit, 230A, 230B CAS processing unit, 231A, 231B card insertion unit, 232A, 232B CAS management unit, 233A, 233B CAS descrambling section, 240A, 240B control section, 250A output section, 251A display section, 252A speaker

Claims (8)

A broadcasting system comprising a transmitting device that transmits an encrypted broadcast signal and a plurality of receiving devices that receive the broadcast signals transmitted from the transmitting device ,
The receiving device
a receiving unit that receives an encrypted broadcast signal transmitted from the transmitting device;
a connection unit for connecting an external storage medium on which information for decoding the encrypted broadcast signal is recorded;
a management unit that manages management information that associates identification information that can identify the receiving device with information recorded in the external storage medium;
a decoding unit that decodes an encrypted broadcast signal received by the receiving unit based on the management information managed by the management unit;
with
The transmitting device
Identification capable of identifying the receiving device for each combination of identification information capable of identifying the receiving device and information recorded in the external storage medium based on the management information managed by the management unit of the receiving device a key generation unit that generates an encryption key containing information and information recorded on the external storage medium;
an encryption unit that encrypts broadcast data obtained by digitizing a video signal and an audio signal of a broadcast program and multiplexing them with additional information using an encryption key generated by the key generation unit;
a transmission unit that transmits, as the encrypted broadcast signal, a broadcast signal obtained by modulating the broadcast data encrypted by the encryption unit, and transmits an encryption key generated by the key generation unit to the receiving device;
with
The decoding unit of the receiving device,
decrypting the encrypted broadcast signal received by the receiving unit based on the encryption key transmitted from the transmitting device and the management information managed by the management unit;
The transmission unit
Information recorded in different external storage media having the same identification information for identifying the receiving devices is associated with the management information managed by the management units of the plurality of receiving devices . If there is an object, sending update information of information recorded in different external storage media associated with the same identification information to a plurality of the receiving devices with the same identification information,
broadcasting system. A receiving device for receiving a broadcast signal transmitted from a transmitting device,
a receiving unit that receives an encrypted broadcast signal transmitted from the transmitting device;
a connection unit for connecting an external storage medium on which information for decoding the encrypted broadcast signal is recorded;
a management unit that manages management information that associates identification information that can identify the receiving device with information recorded in the external storage medium;
a decoding unit that decodes an encrypted broadcast signal received by the receiving unit based on the management information managed by the management unit;
with
The transmitting device
Identification capable of identifying the receiving device for each combination of identification information capable of identifying the receiving device and information recorded in the external storage medium based on the management information managed by the management unit of the receiving device a key generation unit that generates an encryption key containing information and information recorded on the external storage medium;
an encryption unit that encrypts broadcast data obtained by digitizing a video signal and an audio signal of a broadcast program and multiplexing them with additional information using an encryption key generated by the key generation unit;
a transmission unit that transmits, as the encrypted broadcast signal, a broadcast signal obtained by modulating the broadcast data encrypted by the encryption unit, and transmits an encryption key generated by the key generation unit to the receiving device;
with
The decryption unit
decrypting the encrypted broadcast signal received by the receiving unit based on the encryption key transmitted from the transmitting device and the management information managed by the management unit;
The receiving unit
Information recorded in different external storage media having the same identification information for identifying the receiving devices is associated with the management information managed by the management units of the plurality of receiving devices. If there is an object, receiving update information of information recorded in different external storage media associated with the same identification information from the transmission device for the plurality of reception devices with the same identification information,
receiving device. a receiving unit that receives an encrypted broadcast signal; a connection unit that connects an external storage medium in which information for decoding the encrypted broadcast signal is recorded; A management unit that manages management information associated with information recorded on a storage medium, and a decoding unit that decodes an encrypted broadcast signal received by the reception unit based on the management information managed by the management unit. A transmitting device for transmitting a broadcast signal to a receiving device comprising
generating an encryption key including identification information capable of identifying the receiving device and information recorded in the external storage medium for each combination of identification information capable of identifying the receiving device and information recorded in the external storage medium ; a key generator that
an encryption unit that encrypts broadcast data obtained by digitizing a video signal and an audio signal of a broadcast program and multiplexing them with additional information, using an encryption key generated by the key generation unit;
a transmission unit that transmits , as the encrypted broadcast signal, a broadcast signal obtained by modulating the broadcast data encrypted by the encryption unit, and transmits an encryption key generated by the key generation unit to the receiving device;
with
The transmission unit
Information recorded in different external storage media having the same identification information for identifying the receiving devices is associated with the management information managed by the management units of the plurality of receiving devices. If there is an object, sending update information of information recorded in different external storage media associated with the same identification information to a plurality of the receiving devices with the same identification information,
transmitter. A control method in a broadcasting system comprising a transmission device that transmits an encrypted broadcast signal and a plurality of reception devices that receive the broadcast signal transmitted from the transmission device ,
A receiving device comprising a connection unit for connecting an external storage medium in which information for decoding the encrypted broadcast signal is recorded,
a receiving step in which a receiving unit receives an encrypted broadcast signal transmitted from the transmitting device;
a management step in which a management unit manages management information that associates identification information that can identify the receiving device with information recorded in the external storage medium;
a decryption step in which the decryption unit decrypts the encrypted broadcast signal received by the reception unit based on the management information managed by the management unit;
has
The transmitting device
A key generation unit generates information for each combination of identification information that can identify the reception device and information recorded in the external storage medium, based on the management information managed by the management unit of the reception device. a generation step of generating a cryptographic key containing identification information capable of identifying the and information recorded in the external storage medium;
an encryption step in which an encryption unit encrypts broadcast data obtained by digitizing a video signal and an audio signal of a broadcast program and multiplexing them with additional information using an encryption key generated by the key generation unit;
Transmission in which a transmission unit transmits a broadcast signal obtained by modulating broadcast data encrypted by the encryption unit as the encrypted broadcast signal, and transmits an encryption key generated by the key generation unit to the reception device. a step;
has
In the decoding step ,
decrypting the encrypted broadcast signal received by the receiving unit based on the encryption key transmitted from the transmitting device and the management information managed by the management unit;
The transmitting device
Information recorded in the external storage medium by the transmission unit that has the same identification information that can identify the reception device among the management information managed by the management units of the plurality of reception devices but is different. transmission of update information of information recorded in different external storage media associated with the same identification information to a plurality of the receiving devices with the same identification information step,
A control method further comprising : A control method in a receiving device having a connection unit for connecting an external storage medium in which information for decoding an encrypted broadcast signal is recorded,
a receiving step in which the receiving unit receives an encrypted broadcast signal transmitted from a transmission device that transmits the broadcast signal;
a management step in which a management unit manages management information that associates identification information that can identify the receiving device with information recorded in the external storage medium;
a decryption step in which the decryption unit decrypts the encrypted broadcast signal received by the reception unit based on the management information managed by the management unit;
has
The transmitting device
Identification capable of identifying the receiving device for each combination of identification information capable of identifying the receiving device and information recorded in the external storage medium based on the management information managed by the management unit of the receiving device a key generation unit that generates an encryption key containing information and information recorded on the external storage medium;
an encryption unit that encrypts broadcast data obtained by digitizing a video signal and an audio signal of a broadcast program and multiplexing them with additional information using an encryption key generated by the key generation unit;
a transmission unit that transmits, as the encrypted broadcast signal, a broadcast signal obtained by modulating the broadcast data encrypted by the encryption unit, and transmits an encryption key generated by the key generation unit to the receiving device;
with
The decoding unit, in the decoding step,
decrypting the encrypted broadcast signal received by the receiving unit based on the encryption key transmitted from the transmitting device and the management information managed by the management unit;
The receiving unit
Information recorded in different external storage media having the same identification information for identifying the receiving devices is associated with the management information managed by the management units of the plurality of receiving devices. a receiving step of receiving update information of information recorded in different external storage media associated with the same identification information from the transmitting device for the plurality of the receiving devices having the same identification information, if there is any ,
A control method further comprising: a receiving unit that receives an encrypted broadcast signal; a connection unit that connects an external storage medium in which information for decoding the encrypted broadcast signal is recorded; A management unit that manages management information associated with information recorded on a storage medium, and a decoding unit that decodes an encrypted broadcast signal received by the reception unit based on the management information managed by the management unit. A control method in a transmitting device that transmits a broadcast signal to a receiving device comprising :
A key generation unit includes identification information capable of identifying the receiving device and information recorded in the external storage medium for each combination of identification information capable of identifying the receiving device and information recorded in the external storage medium. a key generation step for generating a cryptographic key that is
an encryption step in which an encryption unit encrypts broadcast data obtained by digitizing a video signal and an audio signal of a broadcast program and multiplexing them with additional information using an encryption key generated by the key generation unit;
Transmission in which a transmission unit transmits a broadcast signal obtained by modulating broadcast data encrypted by the encryption unit as the encrypted broadcast signal, and transmits an encryption key generated by the key generation unit to the reception device. a step;
Information recorded in the external storage medium by the transmission unit that has the same identification information that can identify the reception device among the management information managed by the management units of the plurality of reception devices but is different. transmission of update information of information recorded in different external storage media associated with the same identification information to a plurality of the receiving devices with the same identification information a step;
A control method with A computer as a receiving device provided with a connection unit for connecting an external storage medium in which information for decoding an encrypted broadcast signal is recorded,
a receiving step of receiving an encrypted broadcast signal transmitted from a transmitter that transmits the broadcast signal;
a management step of managing management information that associates identification information that can identify the receiving device with information recorded in the external storage medium;
a decoding step of decoding the encrypted broadcast signal received in the receiving step based on the management information;
and
The transmitting device
Identification capable of identifying the receiving device for each combination of identification information capable of identifying the receiving device and information recorded in the external storage medium based on the management information managed by the managing step of the receiving device a key generation unit that generates an encryption key containing information and information recorded on the external storage medium;
an encryption unit that encrypts broadcast data obtained by digitizing a video signal and an audio signal of a broadcast program and multiplexing them with additional information using an encryption key generated by the key generation unit;
a transmission unit that transmits, as the encrypted broadcast signal, a broadcast signal obtained by modulating the broadcast data encrypted by the encryption unit, and transmits an encryption key generated by the key generation unit to the receiving device;
with
In the decoding step,
decrypting the encrypted broadcast signal received by the receiving step based on the encryption key transmitted from the transmitting device and the management information managed by the managing step;
The management information managed by the management step for the plurality of receivers is associated with information recorded in different external storage media having the same identification information for identifying the receivers. a receiving step of receiving update information of information recorded in different external storage media associated with the same identification information from the transmitting device for the plurality of the receiving devices having the same identification information, if there is any ,
A program for further execution of a receiving unit that receives an encrypted broadcast signal; a connection unit that connects an external storage medium in which information for decoding the encrypted broadcast signal is recorded; A management unit that manages management information associated with information recorded on a storage medium, and a decoding unit that decodes an encrypted broadcast signal received by the reception unit based on the management information managed by the management unit. A computer as a transmitting device that transmits a broadcast signal to a receiving device comprising
generating an encryption key including identification information capable of identifying the receiving device and information recorded in the external storage medium for each combination of identification information capable of identifying the receiving device and information recorded in the external storage medium ; a key generation step that
an encryption step of encrypting broadcast data obtained by digitizing a video signal and an audio signal of a broadcast program and multiplexing them with additional information using the encryption key generated in the key generation step;
a transmission step of transmitting , as the encrypted broadcast signal, a broadcast signal obtained by modulating the broadcast data encrypted in the encryption step, and transmitting the encryption key generated in the key generation step to the receiving device;
Information recorded in different external storage media having the same identification information for identifying the receiving devices is associated with the management information managed by the management units of the plurality of receiving devices. a transmitting step of transmitting update information of information recorded in different external storage media associated with the same identification information to a plurality of the receiving devices having the same identification information, if there is such a thing;
program to run the

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