JP2010081113A - Broadcast reception system, broadcast receiver, and method of updating key information - Google Patents

Abstract

A period during which content information cannot be acquired when reception of a broadcast wave different from the broadcast wave being received is started after key information for decrypting the content information in each broadcast wave is updated. Is prevented from occurring.
When a key information related to a broadcast wave received by the broadcast receiving apparatus is updated, the broadcast receiving apparatus receives a broadcast wave different from the broadcast wave through the broadcast receiving apparatus. Update key information related to broadcast waves other than the received broadcast wave.
[Selection] Figure 1

Description

  The present invention relates to a broadcast receiving system, a broadcast receiving apparatus, and a key information updating method.

  Currently, content information included in broadcast waves such as digital terrestrial television broadcasting is protected by scrambling with key information in accordance with the standard (Non-Patent Document 1) defined by the Radio Industries Association (ARIB). Has been. Specifically, a B-CAS method using an IC card with a unique ID assigned to each broadcast receiving apparatus is known (Patent Document 1). In the B-CAS system, a scramble key used for decoding scrambled content information is generated by decrypting an ECM (Entitlement Control Message) with a key called a work key. The work key is stored in the IC card.

  In the control method (content protection method) at the time of reception in Part 3 of Non-Patent Document 1, a new method for protecting content information by software without using hardware such as an IC card has been additionally standardized. (Hereafter, this standard is referred to as a new RMP method). In the new RMP method, a work key is transmitted for each broadcaster by EMM (Entitlement Management Message). A key for decrypting the work key (hereinafter referred to as a device key) is stored in the broadcast receiving apparatus. The device key is determined for each model of the broadcast receiving apparatus, and can be updated by decrypting the EMM with a predetermined algorithm stored in the broadcast receiving apparatus.

  The new RMP method requires three pieces of key information: a scramble key, a work key, and a device key in order to obtain content information. It is updated as appropriate using the broadcast wave, and the old generation key information is invalidated. Such a revoking measure to eliminate unauthorized receivers by changing generations of key information is called revocation.

The EMM and the ECM that transmit key information of a new generation when revocation is performed are transmitted at a predetermined cycle in the broadcast wave of the broadcaster specified by the user by channel selection or the like. In revocation, a work key update transition period is set. Therefore, if a broadcaster's program specified by channel selection is being viewed, even if revocation is performed, the broadcaster's work key must be updated, and if necessary, the device key Since it can also be updated, there is no invisible time.
JP-A-4-138735 Japan Radio Industry Association, Standard "Access Control Method for Digital Broadcasting" ARIB STD-B25 Ver5.0

  However, revocation in the new RMP method is performed in the same manner for broadcast waves other than the broadcast wave specified by channel selection. Therefore, when viewing of content information of another broadcast wave is started by channel selection after the revocation occurs, in the related art, there is a possibility that viewing may be disabled for a certain period until a new work key related to the broadcast wave can be acquired. there were.

  The present invention has been made for the purpose of solving such problems of the prior art. The present invention makes it impossible to acquire content information when reception of a broadcast wave different from the broadcast wave being received is started after the key information for decrypting the content information in each broadcast wave is updated. The purpose is to provide a technique for preventing the period from occurring.

  The object is to select and receive a broadcast wave and to receive update information for updating key information for decrypting encrypted information included in the broadcast wave; Storage means for storing information for each broadcast wave receivable by the broadcast receiving means, and encrypting information included in the broadcast wave received by the broadcast receiving means is stored in the key information corresponding to the broadcast wave. A broadcast receiving system in which two first and second broadcast receiving apparatuses that decrypt and acquire content information are connected to each other so as to be communicable with each other. A determination unit that determines whether or not the key information corresponding to the broadcast wave being received has been updated, and the broadcast reception unit of the own device receives the key information when the determination unit determines that the key information has been updated. Broadcast wave Transmits to the second broadcast receiving device instruction information including information on at least the broadcast wave received by the broadcast receiving means of the device for receiving the different broadcast waves by the second broadcast receiving device. Based on transmission information, update information receiving means for receiving update information for updating key information corresponding to the different broadcast waves from the second broadcast receiving apparatus, and update information received by the update information receiving means And updating means for updating key information corresponding to the different broadcast waves stored in the storage means, wherein the second broadcast receiving device is transmitted from the first broadcast receiving device. Based on the instruction information, the broadcast receiving unit of the device receives the different broadcast waves and acquires the update information for each of the different broadcast waves; and the update acquired by the acquisition unit And returning means for returning the broadcast to the first broadcast receiver is achieved by the broadcast receiving system according to the invention, characterized in that it comprises a.

  Further, the object is to select and receive a broadcast wave, and broadcast receiving means for receiving update information for updating key information for decrypting encrypted information included in the broadcast wave; Storage means for storing the key information for each broadcast wave that can be received by the broadcast receiving means, and the encrypted information included in the broadcast wave received by the broadcast receiving means is stored in the key corresponding to the broadcast wave. A broadcast receiving apparatus that obtains content information by decrypting with information, comprising two broadcast receiving means, and whether key information corresponding to a broadcast wave received by the first broadcast receiving means has been updated A determination means for determining whether or not the key information has been updated by the determination means, a broadcast wave different from the broadcast wave received by the first broadcast reception means is transmitted to the second broadcast By receiving means And updating means for acquiring the update information for each of the different broadcast waves, and updating the key information corresponding to the different broadcast waves stored in the storage means based on the acquired update information, The present invention is also achieved by a broadcast receiving apparatus according to the present invention.

  Further, the object is to select and receive a broadcast wave and to receive two pieces of broadcast receiving means for receiving update information for updating key information for decrypting encrypted information included in the broadcast wave Storage means for storing the key information for each broadcast wave receivable by the broadcast receiving means, and the encrypted information included in the broadcast wave received by the broadcast receiving means corresponds to the broadcast wave. Whether or not the key information corresponding to the broadcast wave received by the first broadcast receiving means has been updated in the broadcast receiving apparatus that obtains content information by decrypting with the key information. And when the determination is made that the key information has been updated, a broadcast wave different from the broadcast wave received by the first broadcast receiving means is received by the second broadcast receiving means. Let me receive An update step of acquiring the update information for each different broadcast wave, and updating the key information corresponding to the different broadcast wave stored in the storage unit based on the acquired update information. This is also achieved by the key information update method according to the present invention.

  According to the present invention, when reception of a broadcast wave different from the broadcast wave being received is started after the key information for decrypting the content information is updated in each broadcast wave, the content information cannot be acquired. It is possible to prevent the occurrence of a period.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments. Further, the embodiment of the present invention shows the most preferable mode of the invention, and does not limit the scope of the invention.

[First Embodiment]
Hereinafter, the broadcast receiving system according to the first embodiment will be described. FIG. 1 is a block diagram schematically showing a functional configuration of a broadcast receiving system 1 according to the first embodiment.

  As shown in FIG. 1, the broadcast receiving system 1 is connected so that two can communicate with each other, and each receives a broadcast wave by selecting a broadcast wave 100, 110 (first broadcast receiver, second broadcast). Receiving device). The broadcast receiving system 1 only needs to include at least two broadcast receiving apparatuses. Specific examples of the broadcast receiving devices 100 and 110 include display devices such as plasma television devices and liquid crystal television devices, and recording devices such as DVD recorders. Broadcast receiving apparatuses 100 and 110 may be movable apparatuses such as a car navigation system and a mobile phone. The broadcast waves include various data broadcasts such as terrestrial digital television broadcasts and digital radio broadcasts. In this embodiment, terrestrial digital televisions that are revoked by the new RMP method in accordance with the standard defined by ARIB. John broadcasting.

  The control unit 101 performs central control of the broadcast receiving apparatus 100 and various calculations. Similarly, the control unit 111 performs central control of the broadcast receiving apparatus 110 and various calculations. Specifically, the control unit can be configured by an integrated circuit such as a CPU, a RAM, a ROM, or a microcontroller having the same function as these. For example, in a control unit composed of a CPU, a RAM, a ROM, etc., the CPU expands program data stored in the ROM into a work area of the RAM, and performs central control of the broadcast receiving apparatus by cooperation of the CPU and program data. Realize.

  The broadcast receiving unit 102 performs broadcast reception processing for selecting and receiving a broadcast wave under the control of the control unit 101. Similarly, the broadcast receiving unit 112 performs a broadcast receiving process for selecting and receiving a broadcast wave under the control of the control unit 111. Specifically, the broadcast receiving unit includes a tuner circuit that selects and receives a broadcast wave of an antenna or terrestrial digital television broadcast, and a decode circuit that decodes a signal output from the tuner circuit (both not shown) ) Etc.

  In the broadcast receiving unit, a channel selection process for receiving a broadcast wave of a channel designated by the operation unit 109 is performed. Further, the broadcast receiving unit performs processing for separating EEM and ECM obtained by decoding the signal acquired by the channel selection process and outputting the separated signal as a broadcast signal to the subsequent stage. In the present embodiment, the number of channels that can be received at one time by the broadcast receiving unit is one. That is, the broadcast receiving device 100 and the broadcast receiving device 110 in the broadcast receiving system 1 individually select and receive one broadcast wave.

  The decoding unit 103 performs decoding processing in the new RMP method on the broadcast signal output from the broadcast receiving unit 102 under the control of the control unit 101, and acquires content information such as video and audio. Similarly, the decoding unit 113 performs decoding processing on the broadcast signal output from the broadcast receiving unit 112 under the control of the control unit 111, and acquires content information such as video and audio.

  Specifically, the decoding unit can be configured by an integrated circuit such as a CPU, a RAM, a ROM, or a microcontroller having the same function as the control unit. The decoding unit decrypts the device key from the EMM, decrypts the work key from the EMM and the device key, decrypts the scramble key from the ECM and the work key, and decrypts the broadcast signal using the scramble key. Processing and key update processing are performed. In the decoding unit, processing for decoding video and audio of the broadcast signal is performed.

  Note that the key update processing in the decoding unit is performed by EMM and ECC included in the broadcast wave at the time of revocation. For example, a device key for a new generation is acquired and updated by decrypting the EMM with a predetermined algorithm stored in advance in a ROM or the like. The work key is decrypted with the EMM and the device key, and a new generation work key is acquired and updated. The scramble key is decrypted with the ECM and the work key, and a new generation scramble key is acquired and updated. That is, the EMM and ECC included in the broadcast wave at the time of revocation are update information for updating the device key, work key, and scramble key to a new generation key.

  The key recording unit 104 stores key information such as a device key, a work key, and a scramble key used for descrambling the broadcast in the broadcast receiving apparatus 100, and data related thereto. Note that a work key or the like that differs depending on the broadcaster is stored for each broadcast wave of the broadcaster. The data related to the key information includes a device ID necessary for acquiring a device key unique to the model from the EMM. Similarly, the key recording unit 114 stores key information in the broadcast receiving apparatus 110 and data related thereto. Specifically, the key recording unit is configured by a nonvolatile memory device such as a flash memory or a hard disk drive.

  The communication unit 105 performs data communication between the broadcast receiving device 100 and an external device under the control of the control unit 101. Similarly, the communication unit 115 performs data communication between the broadcast receiving apparatus 110 and an external device under the control of the control unit 111. The communication method with the external device in the communication unit may be wireless communication or wired communication. Specifically, it may be USB or IEEE1394, and is not particularly limited. Note that data communication at the application level in the broadcast receiving apparatus 100 and the broadcast receiving apparatus 110 is performed by sending and receiving protocols and commands conforming to the above-described USB and IEEE1394. For example, USB 1.1 with a maximum transfer rate of 12 Mbps, USB 2.0 with a maximum transfer rate of 480 Mbps (the same applies to IEEE 1394) and the like, protocols and command transmission / reception methods are also specified in detail.

  The power supply unit 106 supplies power to the broadcast receiving device 100. Similarly, the power supply unit 116 supplies power to the broadcast receiving apparatus 110. Specifically, the power supply unit includes a power supply control circuit for supplying power supplied from the outside to each unit of the device itself. Note that the power supply unit may include a power supply source such as a battery.

  The audio reproduction unit 107 performs audio output in the broadcast receiving device 100 under the control of the control unit 101. Specifically, the audio reproduction unit 107 includes a speaker, headphones, an external audio output mechanism, and its control circuit. For example, the audio reproduction unit 107 performs audio output of content information received by the broadcast receiving device 100.

  The display unit 108 displays an image under the control of the control unit 101. For example, the display unit 108 displays content information received by the broadcast receiving device 100. Specifically, the display unit 108 includes a CRT, a liquid crystal panel, an organic EL panel, and the like. Note that the display unit 108 may have a function of connecting a monitor to the outside.

  The operation unit 109 receives an operation instruction from the user in the broadcast receiving apparatus 100 and outputs the operation instruction to the control unit 101. Specifically, the operation unit 109 is configured with buttons, cross keys, and the like. Note that the operation unit 109 may be configured by a remote controller that can be remotely operated by infrared communication or the like.

  For example, the operation unit 109 receives a channel selection for designating a broadcast wave received by the broadcast receiving unit 102 from the user. The control unit 101 causes the broadcast receiving unit 102 to receive a broadcast wave corresponding to channel selection by the operation unit 109 and causes the display unit 108 to display content information included in the broadcast wave. Therefore, the user can view (receive) desired content information by operating the operation unit 109.

  Note that the broadcast receiving apparatus 110 in this embodiment does not include an audio reproduction unit, a display unit, and an operation unit, but the broadcast reception device 110 also includes an audio reproduction unit, a display unit, and an operation unit. It doesn't matter.

  Next, the operation content of the broadcast receiving system 1 in this embodiment will be described. FIG. 2 is a flowchart showing the operation content of the broadcast receiving system 1.

  As shown in FIG. 2, in S201, the control unit 101 of the broadcast receiving apparatus 100 determines whether or not revocation has occurred for the currently received channel (channel information A) decoded by the decoding unit 103. judge. That is, the control unit 101 determines whether or not the key information related to the channel has been updated by determining whether or not revocation has occurred in the currently received channel (determination unit). If revocation has occurred, the control unit 101 advances the process to S202, and if revocation has not occurred, returns the process to S201.

  Whether or not revocation has occurred in S201 is determined using flag information accompanying the broadcast wave received by the broadcast receiving unit 102. For example, when the flag information is ON, the control unit 101 determines that revocation has occurred in the channel information A that is currently being received, and update information is included in the broadcast wave of that channel.

  In addition, the control unit 101 may measure the EMM update period and determine the occurrence of revocation using the update interval. The EMM update interval is usually on a monthly basis, but when revocation occurs, it becomes a short period of time such as one day or less in order to quickly exclude unauthorized broadcast receivers. Therefore, the control unit 101 can determine the occurrence of revocation by measuring the EMM update period and detecting an update in a short period that is out of the monthly update interval. The update period of the EMM stores the EMM at the time of the previous reception and its time stamp in the memory, and when an update is detected by comparing the EMM at the next reception with the stored EMM, It can be measured by referring to the time stamp. The EMM update period can also be measured by storing the update time in a memory when an EMM update is detected during reception.

  Next, in S <b> 202 a, the control unit 101 of the broadcast receiving apparatus 100 broadcasts the model information Dx and the channel information A, which are device IDs (model information) of the broadcast receiving apparatus 100 stored in the key recording unit 104, through the communication unit 105. Transmit to the receiving device 110. That is, the broadcast receiving apparatus 100 uses the channel information A and the model information Dx to the broadcast receiving apparatus 110 as instruction information for causing the broadcast receiving apparatus 110 to receive a broadcast wave different from the broadcast wave currently received by the own apparatus. Send. In S202b, the control unit 111 of the broadcast receiving apparatus 110 receives the model information Dx and the channel information A transmitted from the broadcast receiving apparatus 100 by the communication unit 115 and stores them in the RAM or the like. In S202a and S202b, when the broadcast receiver 110 is not turned on and the channel information A and the model information Dx cannot be transmitted, the control unit 101 may retransmit after waiting for a predetermined period. .

  Next, in S <b> 203, the control unit 111 of the broadcast receiving apparatus 110 instructs the broadcast receiving unit 112 to cause the broadcast receiving unit 112 to start receiving broadcast waves of channel information C that is a channel other than the channel information A. That is, the control unit 111 causes the broadcast reception unit 112 to receive a broadcast wave of channel information C different from the channel information A, and updates the key information of the broadcast reception device 100 from the EMM in the broadcast wave of the channel information C. Acquisition means for acquiring the update information. In S203, the control unit 111 may determine whether or not the broadcast receiving unit 112 is receiving a broadcast wave, and may start receiving the broadcast wave of the channel information C when the broadcast wave is not being received. Further, when the broadcast wave is being received by the broadcast receiving unit 112, the control unit 111 may start receiving the broadcast wave of the channel information C after waiting until reception by the broadcast receiving unit 112 is completed.

  Next, in S <b> 204, the control unit 111 of the broadcast receiving apparatus 110 is an EMM corresponding to the model information Dx that is the device ID of the broadcast receiving apparatus 100 from the EMM of the broadcast wave of the channel information C decoded by the decoding unit 113. It is determined whether or not This is because in EMM, update information (Dc) for updating key information in a predetermined order is transmitted to all devices, and Dc related to the broadcast receiving apparatus 100 is transmitted at a predetermined interval. is there. In S204, the control unit 111 advances the process to S205 when Dc is acquired, and returns the process to S204 when Dc is not acquired.

  In S205, the control unit 111 of the broadcast receiving apparatus 110 stores the acquired Dc in the key recording unit 114, and proceeds to S206.

  In S206, whether or not the control unit 111 of the broadcast receiving apparatus 110 can receive the EMM (Dc) corresponding to the model information Dx for all channels except the channel information A that can be received by the broadcast receiving unit 112. Determine. In S206, the control unit 111 proceeds to S207a when Dc can be acquired for all channels except the channel information A, and when Dc cannot be acquired, the channel information C is acquired by the EMM. Change to C 'and return to S203.

  In S <b> 207 a, the control unit 111 of the broadcast receiving device 110 transmits EMM (Dc) corresponding to the model information Dx stored in the key recording unit 114 to the broadcast receiving device 100 through the communication unit 115. That is, the control unit 111 is a reply unit that returns Dc, which is update information included in a broadcast wave of a channel different from the channel information A, to the broadcast receiving apparatus 100. In S207b, the control unit 101 of the broadcast receiving apparatus 100 receives the Dc transmitted from the broadcast receiving apparatus 110 by the communication unit 105 and stores it in the RAM or the like (update information receiving unit).

  Next, in S208, the control unit 101 of the broadcast receiving apparatus 100 transmits Dc received from the broadcast receiving apparatus 110 in S207b to the decoding unit 103. Under the control of the control unit 101, the decoding unit 103 converts the key information (device key, work key) of each channel into a new generation key based on the EMM received by the own device and the Dc from the broadcast receiving device 110. Update to information. The control unit 101 stores the updated key information in the key recording unit 104.

  Note that, in this embodiment, the broadcast receiving apparatus 110 collectively transmits Dc of all channels except the channel information A to the broadcast receiving apparatus 100. However, every time the Dc is acquired in each channel, the acquisition is performed. Dc may be transmitted to the broadcast receiving apparatus 100. Also, the broadcast receiving apparatus 100 may update the key information of the own apparatus every time Dc is received from the broadcast receiving apparatus 110.

[Modification]
Hereinafter, a modification of the first embodiment will be described with reference to FIG. Since the hardware configuration and basic control flow are the same as those in the first embodiment, only the differences will be described below. FIG. 3 is a flowchart illustrating the operation content of the broadcast receiving system 1 in the modification.

  As shown in FIG. 3, S301 is the same processing content as S201. In S302a, the control unit 101 of the broadcast receiving apparatus 100 transmits the EMM collection start instruction and the channel information A as instruction information to the broadcast receiving apparatus 110 through the communication unit 105. In S302b, the control unit 111 of the broadcast receiving apparatus 110 receives the EMM collection start instruction and the channel information A transmitted from the broadcast receiving apparatus 100.

  S303 is the same processing content as S203. In S304, the control unit 111 of the broadcast receiving apparatus 110 determines whether all EMMs in the broadcast wave of the channel information C decoded by the decoding unit 113 have been acquired. Since the EMM is repeatedly transmitted to all devices in a predetermined order, in S304, it is determined whether or not all EMMs have been acquired by determining whether or not the EMM for the same device has been received twice. Judgment. In S304, the control unit 111 proceeds to S305 when all EMMs have been acquired, and returns to S304 when all EMMs have not been acquired.

  In S305, the control unit 111 of the broadcast receiving apparatus 110 stores the acquired EMM in the key recording unit 114, and advances the process to S306.

  In S <b> 306, the control unit 111 of the broadcast receiving apparatus 110 determines whether or not EMMs have been acquired for all channels except for the channel information A that can be received by the broadcast receiving unit 112. In S306, if the control unit 111 has acquired EMMs for all channels except for the channel information A, the control unit 111 proceeds to S307a. If not, the control unit 111 sets the channel information C that has not been acquired by the EMM. Change to 'and return to S303.

  In S307a, the control unit 111 of the broadcast receiving apparatus 110 transmits the EMM stored in the key recording unit 114 to the broadcast receiving apparatus 100 through the communication unit 115. That is, the control unit 111 transmits update information included in a broadcast wave of a channel different from the channel information A, and includes all the EMMs including Dc described above to the broadcast receiving apparatus 100. In S307b, the control unit 101 of the broadcast receiving apparatus 100 receives the EMM transmitted from the broadcast receiving apparatus 110 by the communication unit 105 and stores it in the RAM or the like.

  Next, in S308, the control unit 101 of the broadcast receiving device 100 transmits the EMM received from the broadcast receiving device 110 in S307b to the decoding unit 103. The decoding unit 103 selects the EMM corresponding to the device ID of the broadcast receiving apparatus 100 from the EMM received by the own apparatus and the EMM from the broadcast receiving apparatus 110, and updates the key information of each channel. The control unit 101 stores the updated key information in the key recording unit 104.

  In the modification, the broadcast receiving apparatus 110 collectively transmits the EMMs of all the channels except the channel information A to the broadcast receiving apparatus 100. However, every time the EMM is acquired in each channel, the acquired EMM is transmitted. May be transmitted to the broadcast receiving apparatus 100. Moreover, the broadcast receiving apparatus 100 may update the key information of its own apparatus every time it receives an EMM from the broadcast receiving apparatus 110.

  As described above, the broadcast receiving system 1 determines whether or not a revocation related to a channel currently being received has occurred in the broadcast receiving apparatus 100 which is one of the broadcast receiving apparatuses. When revocation has occurred, the broadcast receiving apparatus 100 is necessary for updating the key information regarding a channel other than the channel currently being received by the own apparatus through the broadcast receiving apparatus 110 which is the other broadcast receiving apparatus. Obtain an EMM. The broadcast receiving apparatus 100 updates the key information of channels other than the channel currently being received using the EMM acquired through the broadcast receiving apparatus 110. Therefore, when the broadcast receiving apparatus 100 starts receiving another channel after revocation occurs in the channel being received, the broadcast receiving device 100 cannot acquire the content information because the key information has already been updated. Can be prevented from occurring.

  Also, the broadcast receiving apparatus 110 may transmit only Dc corresponding to the model information Dx to the broadcast receiving apparatus 100 for EMMs included in broadcast waves of a channel different from the channel information A. In this case, the broadcast receiving apparatus 100 only needs to perform processing for Dc transmitted from the broadcast receiving apparatus 110. Further, the broadcast receiving apparatus 110 may be configured to transmit all EMMs included in a broadcast wave of a channel different from the channel information A to the broadcast receiving apparatus 100.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a block diagram schematically showing a functional configuration of the broadcast receiving apparatus 400 according to the second embodiment. FIG. 5 is a flowchart showing the operation content of the broadcast receiving apparatus 400. Since the hardware configuration and the basic control flow are the same as those in the first embodiment, only the differences will be described below.

  As shown in FIG. 4, the control unit 401 is the same as the control unit 101. The first broadcast receiving unit 402 and the second broadcast receiving unit 403 are the same as the broadcast receiving unit 102, respectively. The decoding unit 404 is the same as the decoding unit 103. The key recording unit 405 is the same as the key recording unit 104. The power supply unit 406 is the same as the power supply unit 106. The audio reproduction unit 407 is the same as the audio reproduction unit 107. The display unit 408 is the same as the display unit 108. The operation unit 409 is the same as the operation unit 109.

  That is, the broadcast receiving apparatus 400 has the same configuration as the broadcast receiving apparatus 100 except that it includes two broadcast receiving units that select and receive broadcast waves and the number of channels that can be received simultaneously is two. Note that the broadcast receiving apparatus 400 only needs to include at least two broadcast receiving units in order to receive broadcast waves of channels other than the channel being received.

  Next, the operation content of the broadcast receiving apparatus 400 in this embodiment will be described. As shown in FIG. 5, in step S <b> 501, the control unit 401 determines whether or not revocation has occurred for the channel information A currently being received decoded by the decoding unit 404. At this time, the channel information A is received by the first broadcast receiving unit 402 as the first receiving means.

  When revocation occurs, the control unit 401 advances the process to S502, and when revocation does not occur, returns the process to S501. Note that whether or not revocation has occurred is determined in the same manner as in the first embodiment. When revocation occurs, the control unit 401 updates the key information related to the channel information A stored in the key recording unit 405 when revocation occurs.

  In step S <b> 502, the control unit 401 instructs the second broadcast receiving unit 403 and the decoding unit 404 as the second receiving unit to receive a channel other than the channel information A received by the first broadcast receiving unit 402. Reception of channel information C is started. That is, the broadcast receiving apparatus 400 receives the broadcast wave different from the broadcast wave currently received by the first broadcast receiving unit 402 by the second broadcast receiving unit 403.

  Next, in step S503, the control unit 401 determines whether or not Dc, which is an EMM corresponding to the device ID of the broadcast receiving device 400, can be acquired from the EMMs included in the broadcast wave of the channel information C decoded by the decoding unit 404. Determine. In step S503, the control unit 401 proceeds to step S504 if Dc is acquired, and returns to step S503 if Dc is not acquired.

  Next, in step S504, under the control of the control unit 401, the decoding unit 404 updates the key information related to the channel information C stored in the key recording unit 405 using Dc.

  Next, in S505, the control unit 401 determines whether or not the key information regarding all the channels that can be received by the second broadcast receiving unit 403 except the channel information A has been updated. In step S505, the control unit 401 ends the process if the key information can be updated, and changes the channel information C to channel information C ′ in which the key information cannot be updated if the key information cannot be updated. Return processing to.

  As described above, the broadcast receiving apparatus 400 determines the occurrence of revocation in the channel currently being received, and if revocation occurs, the second channel reception unit 403 that is not used for reception uses the key of the other channel. Update information (Dc) for updating the information is acquired. The broadcast receiving apparatus 400 updates the key information of a channel other than the channel currently being received by the update information acquired through the second broadcast receiving unit 403. Therefore, in the broadcast receiving apparatus 400, even when reception of another channel is started after revocation occurs in the channel being received, the content information cannot be acquired because the key information has already been updated. Can be prevented from occurring.

  Note that the description in the above-described embodiment shows an example, and the present invention is not limited to this. The configuration and operation in the embodiment described above can be changed as appropriate.

  For example, in the first and second embodiments, the update information is acquired for all channels other than the channel information A and the key information related to each channel is updated. However, only the channels for which the update information can be acquired are illustrated. The key information may be updated. Actually, revocation occurs in the channel being received, and at the same time, revocation does not necessarily occur in other channels. Therefore, by updating the key information only for the channels in which revocation has occurred, it is possible to prevent the processing from stalling until revocation occurs in all channels.

(Other embodiments)
The above-described embodiment can also be realized in software by a computer of a system or apparatus (or CPU, MPU, etc.). Therefore, the computer program itself supplied to the computer in order to implement the above-described embodiment by the computer also realizes the present invention. That is, the computer program itself for realizing the functions of the above-described embodiments is also one aspect of the present invention.

  The computer program for realizing the above-described embodiment may be in any form as long as it can be read by a computer. For example, it can be composed of object code, a program executed by an interpreter, script data supplied to the OS, but is not limited thereto. A computer program for realizing the above-described embodiment is supplied to a computer via a storage medium or wired / wireless communication. Examples of the storage medium for supplying the program include a magnetic storage medium such as a flexible disk, a hard disk, and a magnetic tape, an optical / magneto-optical storage medium such as an MO, CD, and DVD, and a nonvolatile semiconductor memory.

  As a computer program supply method using wired / wireless communication, there is a method of using a server on a computer network. In this case, a data file (program file) that can be a computer program forming the present invention is stored in the server. The program file may be an executable format or a source code. The program file is supplied by downloading to a client computer that has accessed the server. In this case, the program file can be divided into a plurality of segment files, and the segment files can be distributed and arranged on different servers. That is, a server apparatus that provides a client computer with a program file for realizing the above-described embodiment is also one aspect of the present invention.

  In addition, a storage medium in which the computer program for realizing the above-described embodiment is encrypted and distributed is distributed, and key information for decrypting is supplied to a user who satisfies a predetermined condition, and the user's computer Installation may be allowed. The key information can be supplied by being downloaded from a homepage via the Internet, for example. Further, the computer program for realizing the above-described embodiment may use an OS function already running on the computer. Further, a part of the computer program for realizing the above-described embodiment may be configured by firmware such as an expansion board attached to the computer, or may be executed by a CPU provided in the expansion board. Good.

It is a block diagram showing typically the functional composition of the broadcast receiving system concerning a 1st embodiment. It is a flowchart which shows the operation | movement content of a broadcast receiving system. It is a flowchart which shows the operation | movement content of the broadcast receiving system in a modification. It is a block diagram which shows typically the functional structure of the broadcast receiver which concerns on 2nd Embodiment. It is a flowchart which shows the operation | movement content of a broadcast receiving apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Broadcast receiving system 100 Broadcast receiving apparatus 101 Control part 102 Broadcast receiving part 103 Decoding part 104 Key recording part 105 Communication part 110 Broadcast receiving apparatus 111 Control part 112 Broadcast receiving part 113 Decoding part 114 Key recording part 115 Communication part 400 Broadcast receiving apparatus 401 control unit 402 first broadcast receiving unit 403 second broadcast receiving unit 404 decoding unit 405 key recording unit

Claims (6)

Broadcast receiving means for selecting and receiving a broadcast wave and receiving update information for updating key information for decrypting encrypted information included in the broadcast wave; and A storage means for storing each broadcast wave that can be received by the reception means, and contents obtained by decrypting encrypted information included in the broadcast wave received by the broadcast reception means with the key information corresponding to the broadcast wave A broadcast receiving system in which two first and second broadcast receiving apparatuses for acquiring information are connected so as to communicate with each other,
The first broadcast receiver is
Determining means for determining whether or not the key information corresponding to the broadcast wave received by the broadcast receiving means of the device itself has been updated;
When it is determined by the determination means that the key information has been updated, at least for causing the second broadcast receiving apparatus to receive a broadcast wave different from the broadcast wave received by the broadcast receiving means of the own apparatus, Transmitting means for transmitting instruction information including information on broadcast waves received by the broadcast receiving means of the own apparatus to the second broadcast receiving apparatus;
Update information receiving means for receiving update information for updating key information corresponding to the different broadcast waves from the second broadcast receiving device;
Updating means for updating key information corresponding to the different broadcast waves stored in the storage means based on the update information received by the update information receiving means;
With
The second broadcast receiver is
Receiving means for receiving the different broadcast waves by the broadcast receiving means of the own apparatus based on the instruction information transmitted from the first broadcast receiving apparatus, and acquiring the update information for each different broadcast wave;
A reply means for returning the update information obtained by the obtaining means to the first broadcast receiving device;
A broadcast receiving system comprising: The transmitting means includes the model information of the own device in the instruction information and transmits the information to the second broadcast receiving device,
The acquisition means acquires only the update information related to the first broadcast receiving device corresponding to the model information from the update information transmitted on the different broadcast waves,
The broadcast receiving system according to claim 1, wherein the reply unit returns update information related to the first broadcast receiving apparatus to the first broadcast receiving apparatus. Update information for connecting to an external broadcast receiving apparatus so as to be able to communicate with each other, selecting and receiving a broadcast wave, and updating key information for decrypting encrypted information included in the broadcast wave Broadcast receiving means for receiving, and storage means for storing the key information for each broadcast wave that can be received by the broadcast receiving means, the encrypted information included in the broadcast wave received by the broadcast receiving means, A broadcast receiving apparatus that acquires content information by decrypting with the key information corresponding to a broadcast wave,
Determining means for determining whether or not the key information corresponding to the broadcast wave received by the broadcast receiving means has been updated;
When the determination means determines that the key information has been updated, at least the broadcast receiving means for causing the external broadcast receiving apparatus to receive a broadcast wave different from the broadcast wave received by the broadcast receiving means. Transmitting means for transmitting instruction information including information on broadcast waves being received to the external broadcast receiving device;
Update information receiving means for receiving update information for updating key information corresponding to the different broadcast waves from the external broadcast receiving device;
Updating means for updating key information corresponding to the different broadcast waves stored in the storage means based on the update information received by the update information receiving means;
A broadcast receiving apparatus comprising: Update information for connecting to an external broadcast receiving apparatus so as to be able to communicate with each other, selecting and receiving a broadcast wave, and updating key information for decrypting encrypted information included in the broadcast wave A broadcast receiving apparatus having broadcast receiving means for receiving,
Receiving the different broadcast wave by the broadcast receiving means based on the instruction information including information on the broadcast wave different from the broadcast wave received by the external broadcast receiver transmitted from the external broadcast receiver; Obtaining means for obtaining the update information for each different broadcast wave;
Reply means for returning the update information acquired by the acquisition means to the external broadcast receiving device;
A broadcast receiving apparatus comprising: Broadcast receiving means for selecting and receiving a broadcast wave and receiving update information for updating key information for decrypting encrypted information included in the broadcast wave; and A storage means for storing each broadcast wave that can be received by the reception means, and content obtained by decrypting encrypted information included in the broadcast wave received by the broadcast reception means with the key information corresponding to the broadcast wave A broadcast receiving device for acquiring information,
Including two broadcast receiving means,
Determining means for determining whether or not the key information corresponding to the broadcast wave received by the first broadcast receiving means has been updated;
If it is determined by the determination means that the key information has been updated, the second broadcast reception means receives a broadcast wave different from the broadcast wave received by the first broadcast reception means, and the different broadcasts are received. An update unit that acquires the update information for each wave, and updates key information corresponding to the different broadcast waves stored in the storage unit based on the acquired update information;
A broadcast receiving apparatus comprising: Two broadcast receiving means for selecting and receiving a broadcast wave and receiving update information for updating key information for decrypting encrypted information included in the broadcast wave; and the key information Storage means for storing each broadcast wave that can be received by the broadcast receiving means, and encrypting information included in the broadcast wave received by the broadcast receiving means is decrypted with the key information corresponding to the broadcast wave. Update method of key information in a broadcast receiving apparatus that acquires content information
A determination step of determining whether or not the key information corresponding to the broadcast wave received by the first broadcast receiving means has been updated;
If it is determined in the determination step that the key information has been updated, the second broadcast receiving unit receives a broadcast wave different from the broadcast wave received by the first broadcast receiving unit, and the different broadcasts are received. An update step of acquiring the update information for each wave, and updating the key information corresponding to the different broadcast waves stored in the storage unit based on the acquired update information;
A method for updating key information, comprising:

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