JP5613066B2 - Conditional reception system, conditional reception method, and conditional reception program - Google Patents

Description

  The present invention relates to a limited reception system, a limited reception method, and a limited reception program for digital broadcasting, and in particular, a transmission apparatus, a reception apparatus, and a limited reception system including a portable terminal for operating the reception apparatus, a limited reception method, And the conditional access program.

  In the digital broadcast conditional access system, streaming-distributed content (video and audio) is scrambled by a digital encryption technique and transmitted to a receiving apparatus. A content provider (for example, a broadcaster) issues descrambling information for descrambling the scrambled content to the contractor. The descrambling information includes a key for descrambling specific content based on the contract, and information on whether or not the content can be viewed (hereinafter referred to as viewing rights). When the descrambling information is set in the receiving device, the received content is unscrambled and the contractor can view the content on the receiving device.

  A television receiver commercially available as a receiving device for receiving content employs a limited reception system called a B-CAS (registered trademark) system, and uses the B-CAS card storing the descrambling information described above. It has been. The television receiver equipped with the B-CAS card uses the descrambling information stored in the B-CAS card to release the received content from being scrambled and display the content after it has been made displayable. .

  The content provider can control whether or not the content of the contractor can be viewed by the key included in the descrambling information and the grant, update, and deletion of the viewing right. For example, in digital broadcasting, content scheduling is performed by CAS (Conditional Access Systems) in accordance with the standard “ARIB STD-B25” (Non-patent Document 1) of the Association of Radio Industries and Businesses (ARIB). The content provider controls whether or not viewing is possible.

"ARIB STD-B25", The Japan Radio Industry Association, version 5.0, March 14, 2007 BS Conditional Access Systems Co., Ltd. http: // www. b-cas. co. jp /

  However, in the configuration of a television receiver that adopts the B-CAS system, an apparatus that extracts a scramble key for decrypting content from a digital broadcast wave containing the content based on descrambling information stored in the B-CAS card ( Since KDA (Key Device Agent), a device that determines the viewing rights of subscribers (RMPI: Light Management and Protection Information) and a device that descrambles content are integrated in the TV receiver, they are delivered in one contract. There is a problem in that it is inconvenient that the right to view the received content cannot be used simultaneously by a plurality of television receivers.

  Therefore, the present invention has been made in view of the above-described problems, and the conditional access system is provided by providing the mobile terminal with the function of the device KDA that acquires the scramble key for decrypting the content from the digital broadcast wave including the content. In other words, it is an object of the present invention to provide a conditional access system, a conditional access method, and a conditional access program that allow content to be viewed simultaneously on all reception devices that can be operated on a portable terminal.

  The present invention proposes the following matters in order to solve the above problems. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.

(1) The present invention is a limited reception system including a content transmission device, one or more content reception devices, and a portable terminal that operates the one or more content reception devices, wherein the content transmission device A scramble means for encrypting with a scramble key (for example, the scramble unit 11 in FIG. 1), the scramble key is encrypted with a work key that is a key unique to the content transmitting apparatus, and at least common information related to content is stored in the work Work key encryption means for creating common information encrypted with a key (for example, work key encryption unit 12 in FIG. 1), encrypted content , encrypted scramble key , and encrypted common First transmission means for multiplexing information and transmitting the information to each of the one or more content reception devices (for example, 1), the work key is encrypted with a master key, which is a key unique to the content recipient, viewing permission information for determining whether the content can be viewed, and the one or more contents. a contract information including the viewing control information for the receiving device, the master key encryption means for producing cipher the individual information in the master key (e.g., master key encryption unit 14 in FIG. 1), is the encrypted A second transmission unit (for example, the key transmission unit 15 in FIG. 1) that transmits the work key and the encrypted individual information to the portable terminal, and the portable terminal is set in advance; wherein the master key, the decrypted from the content transmitting apparatus and the encrypted work key is received and the encrypted individual information, work key decryption to acquire the said contract information and the work key Means (e.g., a work key decryption unit 21 of FIG. 1) and was received from each of the one or more content receiving apparatus, decodes the common information and the encrypted scramble key is the encryption with the work key and the scramble key and the scramble key decryption means for obtaining the common information on the content (e.g., the scramble key decryption unit 22 of FIG. 1) and the common information related to the content acquired by the scrambling key decryption means And whether to view the content based on the viewing availability information for determining whether or not to view the content included in the contract information acquired by the work key decryption unit, and common information regarding the content, , Based on viewing control information for the one or more content receiving devices included in the contract information, The viewing determination unit (for example, the viewing determination unit 23 in FIG. 1) that determines viewing control of the content with respect to the content receiving apparatus, and the viewing determination when the viewing determination unit determines that the content can be viewed. Third transmission means (for example, the scramble key decoding unit 22 in FIG. 1) for transmitting the scramble key to the one or more content receiving devices according to the viewing control determined by the means, each content receiver, the received from the content transmitting apparatus, the encrypted scramble key and the encrypted common information, fourth transmitting means for transmitting to said portable terminal (e.g., the demultiplexing of FIG. 1 Unit 31) and a scramble key received from the portable terminal and the encrypted content received from the content transmitting device And a descrambling means (for example, the descrambling unit 32 in FIG. 1) for decrypting the message with the received scramble key.

According to the present invention, the scramble means encrypts the content with the scramble key.
The work key encryption unit encrypts the scramble key with a work key that is a key unique to the content transmitting apparatus, and creates common information obtained by encrypting at least common information regarding the content with the work key . The first transmission unit multiplexes the encrypted content , the encrypted scramble key , and the encrypted common information , and transmits the multiplexed information to each of the one or more content reception devices. The master key encryption means encrypts the work key with a master key that is a key unique to the content receiver, and also allows viewing permission information for determining whether the content can be viewed and viewing control information for one or more content receiving devices. The second transmission means for creating the individual information obtained by encrypting the contract information including the master key with the master key transmits the encrypted work key and the encrypted individual information to the portable terminal. The work key decryption means decrypts the encrypted work key and the encrypted individual information received from the content transmission device with a preset master key, and obtains the work key and the contract information. . The scramble key decryption means decrypts the encrypted scramble key and the encrypted common information received from each of the one or more content receivers with the work key, and obtains the scramble key and the common information related to the content To do. The viewing judging means is based on the common information regarding the content acquired by the scramble key decrypting means and the viewing enable / disable information for determining whether or not the content included in the contract information acquired by the work key decrypting means is available. Then, whether or not the content can be viewed is determined, and content viewing control for one or more content receiving devices is determined based on the common information regarding the content and the viewing control information for one or more content receiving devices included in the contract information. The third transmission unit transmits the scramble key to one or more content receiving devices according to the viewing control determined by the viewing determination unit when the viewing determination unit determines that the content can be viewed . The fourth transmission means transmits the encrypted scramble key and the encrypted common information received from the content transmission device to the portable terminal. The descrambling means receives the scramble key from the portable terminal, and decrypts the encrypted content received from the content transmission device with the received scramble key. Accordingly, by acquiring a scramble key for decrypting content from a digital broadcast wave including the content in the mobile terminal, each of the one or more content receiving devices that can be operated on the mobile terminal can view the same or different content at the same time. Recording reservations can be made. At the same time, the mobile terminal acquires information about the content and the contract information, so that the mobile terminal can determine whether the content can be viewed. Further, by including the number of viewable content receiving devices and the viewable time as viewing control information for one or more content receiving devices in the contract information, the content viewing control in each of the one or more content receiving devices is performed. Can be done together on a mobile device.

(2) According to the present invention, in the conditional access system according to (1), the portable terminal includes an input unit that receives an operation input from a user, and the scramble key decryption unit includes the input unit, Proposing a conditional access system characterized in that a scramble key is transmitted to a content receiving device for which content selection has been performed in response to receiving an input of content selection by a user for each of the one or more content receiving devices. ing.

According to this invention, the input means receives an operation input from the user. The scramble key decrypting means assigns a scramble key to each of the content receiving apparatuses for which content selection has been performed in response to receiving an input of content selection by the user for each of the one or more content receiving apparatuses via the input means. Send. Therefore, the mobile terminal can transmit only the scramble key necessary for decoding the content to be reproduced to the content receiving device by transmitting the scramble key in response to the input of content selection.

(3) According to the present invention, in the conditional access system according to (1) or (2), the mobile terminal obtains the master key by communication with the content transmission device. is suggesting.

According to the present invention, the mobile terminal acquires the master key by communication with the content transmission device. Therefore, the mobile terminal can acquire the master key in a safer manner.

(4) According to the present invention, there is provided a limited reception method in a limited reception system comprising a content transmission device, one or more content reception devices, and a portable terminal that operates the one or more content reception devices, wherein the content The transmission device encrypts a work key, which is a key unique to the content transmission device, with a master key, which is a key unique to the content receiver, and the viewing availability information for determining whether the content can be viewed and the 1 First information is generated by encrypting contract information including viewing control information for the content receiving apparatus with the master key, and the encrypted work key and the encrypted individual information are transmitted to the portable terminal. A content encrypted by a scramble key, and the scramble encrypted by the work key A second step of multiplexing common information obtained by encrypting a common key and at least common information related to content with the work key, and transmitting the multiplexed information to each of the one or more content receiving devices; and each of the one or more content receiving devices A third step of transmitting the encrypted scramble key and the encrypted common information received from the content transmission device to the portable terminal, and the portable terminal configured in advance as the master A fourth step of decrypting the encrypted work key and the encrypted individual information received from the content transmission device with a key to obtain the work key and the contract information; The terminal receives the encrypted scramble key and the encrypted common information received from each of the one or more content receiving apparatuses. 5 with the work key to obtain the scramble key and the common information related to the content, and the portable terminal uses the common information related to the content acquired in the fifth step, Based on the viewability information for determining the viewability of the content included in the contract information acquired in the fourth step, the viewability of the content is determined, the common information regarding the content, and the contract information A sixth step of determining viewing control of the content for the one or more content reception devices based on the viewing control information for the one or more content reception devices included in the mobile terminal, and When it is determined in step that the content can be viewed, the viewing control determined in the sixth step is followed. Te proposes a conditional method characterized by including, in the seventh step of transmitting the scramble key to the one or more content receiving apparatus (e.g., step S4 in FIG. 1).

According to this invention, first, in the first step, the content transmission apparatus encrypts a work key that is a key unique to the content transmission apparatus with a master key that is a key unique to the content receiver, To create individual information obtained by encrypting contract information including viewing permission information for judging whether or not to view and viewing control information for one or more content receiving apparatuses with a master key, and encrypting the work key and the encrypted individual information To the mobile device. Next, in the second step, the content transmitting apparatus multiplexes the content encrypted with the scramble key, the scramble key encrypted with the work key, and the common information obtained by encrypting at least the common information related to the content with the work key. To each of the one or more content receiving apparatuses. Next, in the third step, each of the one or more content reception devices transmits the encrypted scramble key and the encrypted common information received from the content transmission device to the mobile terminal. Next, in the fourth step, the mobile terminal decrypts the encrypted work key and the encrypted individual information received from the content transmission device with a preset master key, Get contract information. Next, in a fifth step, the mobile terminal decrypts the encrypted scramble key and the encrypted common information received from each of the one or more content reception devices with the work key, and relates to the scramble key and the content. Get common information. Next, in the sixth step, the portable terminal determines whether to view the common information related to the content acquired in the fifth step and the content included in the contract information acquired in the fourth step. Whether or not the content can be viewed is determined based on the availability information, and based on the common information regarding the content and the viewing control information for the one or more content reception devices included in the contract information, Determine viewing control. Next, in the seventh step, when it is determined that the content can be viewed in the sixth step, the mobile terminal receives one or more content scramble keys according to the viewing control determined in the sixth step. Send to device. Accordingly, by acquiring a scramble key for decrypting content from a digital broadcast wave including the content in the mobile terminal, each of the one or more content receiving devices that can be operated on the mobile terminal can view the same or different content at the same time. Recording reservations can be made. At the same time, the mobile terminal acquires information about the content and the contract information, so that the mobile terminal can determine whether the content can be viewed. Further, by including the number of viewable content receiving devices and the viewable time as viewing control information for one or more content receiving devices in the contract information, the content viewing control in each of the one or more content receiving devices is performed. Can be done together on a mobile device.

(5) According to the present invention, in order to cause a computer to execute a limited reception method in a limited reception system including a content transmission device, one or more content reception devices, and a portable terminal that operates the one or more content reception devices. The content transmitting apparatus encrypts a work key, which is a key unique to the content transmitting apparatus, with a master key, which is a key unique to the content receiver, and determines whether the content can be viewed. For creating the individual information obtained by encrypting the contract information including the viewing permission information and the viewing control information for the one or more content receiving devices with the master key, and the encrypted work key and the encrypted individual information A first step of transmitting to a mobile terminal; and a content encrypted by the content transmitting device with a scramble key. A second step of multiplexing the scramble key encrypted with the work key, and at least the common information obtained by encrypting the common information related to the content with the work key, and transmitting the multiplexed information to each of the one or more content receiving devices. A third step in which each of the one or more content reception devices transmits the encrypted scramble key received from the content transmission device and the encrypted common information to the portable terminal; The terminal decrypts the encrypted work key and the encrypted individual information received from the content transmission device with the preset master key, and obtains the work key and the contract information. A fourth step of acquiring and the encrypted received by the mobile terminal from each of the one or more content receiving devices. A fifth step of decrypting the scramble key and the encrypted common information with the work key, and obtaining the scramble key and the common information related to the content; and the portable terminal in the fifth step Based on the acquired common information on the content and the viewing availability information for determining whether to view the content included in the contract information acquired in the fourth step, it is determined whether the content can be viewed. The sixth step of determining viewing control of the content for the one or more content receiving devices based on the common information regarding the content and the viewing control information for the one or more content receiving devices included in the contract information. And when the portable terminal determines that the content can be viewed in the sixth step, Accordance viewing control determined in step sixth, proposes a program to be executed seventh step of transmitting the scramble key to the one or more content receiving apparatus (e.g., step S4 in FIG. 1) and, to a computer doing.

According to the present invention, first, in a first step, the content transmitting apparatus, the work key is a unique key to the content transmitting device, as well as encrypted by the master key is key unique to the content recipient Content To create individual information obtained by encrypting contract information including viewing permission information for judging whether or not to view and viewing control information for one or more content receiving apparatuses with a master key, and encrypting the work key and the encrypted individual information To the mobile device. Then, in a second step, the content transmitting device, the content encrypted with the scramble key, scramble key is encrypted with the work key, and common information common information encrypted by the work key for at least the content multiplexes To each of the one or more content receiving apparatuses. Next, in the third step, each of the one or more content reception devices transmits the encrypted scramble key and the encrypted common information received from the content transmission device to the mobile terminal. Next, in a fourth step, the mobile terminal, the master key which is set in advance, and decrypts the encrypted work key and the encrypted individual information received from the content transmitting apparatus, a work key Get contract information. Next, in a fifth step, the mobile terminal decrypts the encrypted scramble key and the encrypted common information received from each of the one or more content reception devices with the work key, and relates to the scramble key and the content. Get common information. Next, in the sixth step, the portable terminal determines whether to view the common information related to the content acquired in the fifth step and the content included in the contract information acquired in the fourth step. Whether or not the content can be viewed is determined based on the availability information, and based on the common information regarding the content and the viewing control information for the one or more content reception devices included in the contract information, the content of the content for the one or more content reception devices is determined. Determine viewing control. Next, in the seventh step, when it is determined that the content can be viewed in the sixth step, the mobile terminal receives one or more content scramble keys according to the viewing control determined in the sixth step. Send to device. Accordingly, by acquiring a scramble key for decrypting content from a digital broadcast wave including the content in the mobile terminal, each of the one or more content receiving devices that can be operated on the mobile terminal can view the same or different content at the same time. Recording reservations can be made. At the same time, the mobile terminal acquires information about the content and the contract information, so that the mobile terminal can determine whether the content can be viewed. Further, by including the number of viewable content receiving devices and the viewable time as viewing control information for one or more content receiving devices in the contract information, the content viewing control in each of the one or more content receiving devices is performed. Can be done together on a mobile device.

  According to the present invention, since the mobile terminal has the function of the device KDA for acquiring the scramble key for decrypting the content from the digital broadcast wave including the content, all of the operations that can be performed on the mobile terminal in the limited reception method. It is possible to view content at the same time with the receiving device.

It is a block diagram of the conditional access system which concerns on embodiment of this invention. It is a sequence diagram which shows the process of the conditional access system which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the components in the present embodiment can be appropriately replaced with existing components and the like, and various variations including combinations with other existing components are possible. Therefore, the description of the present embodiment does not limit the contents of the invention described in the claims.

<Configuration of conditional access system>
FIG. 1 is a configuration diagram of a conditional access system 1 according to an embodiment of the present invention. The conditional access system 1 is a system that distributes content by a conditional access method, and includes a content transmission device 10, a mobile terminal 20, and content reception devices 30a and 30b as shown in FIG. In this embodiment, the number of content receiving apparatuses is two, but may be one, or may be two or more. Hereinafter, when the content receiving devices 30a and 30b are not distinguished, they are simply referred to as the content receiving device 30.

  The content transmission device 10 and the content reception device 30 are connected by a satellite, a terrestrial wave, an IP network, or a CATV network, and content is transmitted from the content transmission device 10 to the content reception device 30 by a digital broadcast wave. The content transmission device 10 and the portable terminal 20 are connected via a communication network, and information is transmitted and received. The content receiving device 30 and the portable terminal 20 are connected by a wireless line such as infrared rays or wireless radio waves, and information is transmitted and received.

  The content transmission device 10 is a device on the content provider side, and is a device for transmitting content to a viewer terminal (a content reception device 30 described later). In the present embodiment, the viewer is a contractor who has contracted to view content with the content provider, and who views the content contracted to view. As shown in FIG. 1, the content transmission apparatus 10 includes a scramble unit 11, a work key encryption unit 12, a master key encryption unit 14, a multiple transmission unit 13, and a key transmission unit 15.

  The scramble unit 11 generates a scramble key Ks used for encrypting the content, and encrypts the content to be transmitted to the content receiving device 30 with the generated scramble key Ks. The scramble key Ks is generated every few seconds using, for example, a random number.

  The work key encryption unit 12 generates a work key Kw and encrypts the scramble key Ks used for content encryption with the generated work key Kw. Since the scramble key Ks is changed every few seconds, the work key encryption unit 12 encrypts the scramble key Ks with the work key Kw each time. The work key Kw is periodically generated for each content, such as every month. Also, the work key Kw is generated using, for example, a random number, like the scramble key Ks.

  Further, the work key encryption unit 12 may encrypt not only the scramble key Ks but also the common information (ECM: Entitlement Control Message) including at least information related to the content with the work key Kw together with the scramble key Ks. Here, the information related to the content includes information regarding whether or not the content can be viewed and recorded.

  The master key encryption unit 14 encrypts the work key Kw with the master key Km. The master key Km is a key unique to a contractor and is prepared for each contractor. The master key Km is generated when an application for viewing content is made by a contractor, and is stored in a storage unit (not shown). Further, the master key Km is generated using, for example, a random number, like the scramble key Ks and the work key Kw.

In addition, the master key encryption unit 14 encrypts individual information (EMM: Entitlement Management Message) including contract information of each contractor with the work key Kw in addition to the work key Kw. Good. Here, the contract information is information related to the content for which the contractor has viewing rights. The contract information is created or updated when the content provider applies for content viewing by the contractor, and is stored in the storage unit together with the master key Km.

  The multiplex transmission unit 13 multiplexes the content encrypted by the scramble unit 11 and the scramble key Ks encrypted by the work key encryption unit 12, and transmits the result to the content reception device 30 as a digital broadcast wave. When the work key encryption unit 12 encrypts the ECM including the scramble key Ks, the encrypted content and the ECM are multiplexed and transmitted as a digital broadcast wave.

  The key transmission unit 15 transmits the work key Kw encrypted by the master key encryption unit 14 to the mobile terminal 20. When the EMM including the work key Kw is encrypted by the master key encryption unit 14, the key transmission unit 15 transmits the encrypted EMM to the mobile terminal 20.

  The mobile terminal 20 is a terminal on the viewer side and has a function as a remote controller for the content receiving device 30. The mobile terminal 20 only needs to have a communication function and a remote control function, and is, for example, a mobile phone, a smartphone, a PDA, a game machine, or the like. As illustrated in FIG. 1, the mobile terminal 20 includes a work key decryption unit 21, a scramble key decryption unit 22, a master key storage unit 24, and a viewing determination unit 23.

  The master key storage unit 24 stores a master key Km issued in advance from a content provider.

  The work key decryption unit 21 receives the encrypted work key Kw from the content transmission device 10. Then, the work key decryption unit 21 decrypts the received encrypted work key Kw with the master key Km stored in the master key storage unit 24, and acquires the work key Kw. When an encrypted EMM is received from the content transmission apparatus 10, the EMM is decrypted with the master key Km, and contract information is acquired together with the work key Kw.

  The scramble key decryption unit 22 receives the encrypted scramble key Ks from the content receiving device 30. Then, the scramble key decryption unit 22 decrypts the received encrypted scramble key Ks with the work key Kw obtained by the work key decryption unit 21, and obtains the scramble key Ks. When the encrypted ECM is received from the content receiving device 30, the ECM is decrypted with the work key Kw, and information about the content is acquired together with the scramble key Ks.

  Further, the scramble key decryption unit 22 transmits the acquired scramble key Ks to the content receiving device 30. Note that the scramble key decryption unit 22 transmits the scramble key Ks to the content receiving device 30 in response to accepting an input of content selection by the user via the input unit (not shown) of the mobile terminal 20. May be. At this time, a remote control signal for viewing, recording, or reservation of the content selected by the user is also transmitted to the content receiving device 30.

  The viewing determination unit 23 determines whether or not the content can be viewed when the encrypted EMM is received from the content transmission device 10 and the encrypted ECM is received from the content reception device 30. Specifically, the viewing determination unit 23 compares the contract information acquired by the work key decryption unit 21 with the information regarding the content acquired by the scramble key decryption unit 22, and determines whether or not the content can be viewed. .

  If the viewing determination unit 23 determines that the content can be viewed, the viewing determination unit 23 transmits the scramble key Ks acquired by the scramble key decryption unit 22 to the content reception device 30. On the other hand, when it is determined that the content cannot be viewed, the scramble key Ks acquired by the scramble key decryption unit 22 is not transmitted to the content receiver 30. In this manner, it is possible to determine whether or not content viewing is possible in the mobile terminal 20, which has been conventionally performed in the content receiving device 30.

  Similar to the portable terminal 20, the content receiving device 30 is a device on the viewer side, and is a device that reproduces the content received from the content transmitting device 10. The content receiving device 30 only needs to have a function of receiving digital broadcast waves, and is, for example, an STB (Set Top Box) provided with a television receiver or a display device. As shown in FIG. 1, the content receiving device 30 includes a demultiplexing unit 31 and a descrambling unit 32.

  The demultiplexing unit 31 separates the encrypted content and the encrypted scramble key Ks from the digital broadcast wave received from the content transmitting apparatus 10. Then, the demultiplexing unit 31 transmits the separated scramble key Ks to the mobile terminal 20. In addition, the demultiplexing unit 31 transmits the separated encrypted content to the descrambling unit 32.

  When receiving the scramble key Ks from the mobile terminal 20, the descrambler 32 descrambles the encrypted content received from the demultiplexer 31 with the received scramble key Ks, and displays a display unit (not shown). ) To play as content.

<Processing of conditional access system>
The processing of the conditional access system 1 according to the embodiment of the present invention will be described using the sequence diagram shown in FIG.

  The master key encryption unit 14 of the content transmission device 10 encrypts the work key Kw generated by the work key encryption unit 12 of the content transmission device 10 with the master key Km stored in the storage unit in advance. The encrypted work key Kw is transmitted to the mobile terminal 20 by the key transmission unit 15 of the content transmission apparatus 10. Usually, the work key Kw is included in the EMM, and the master key encryption unit 14 encrypts the EMM including the work key Kw, and transmits the encrypted EMM to the mobile terminal 20 by the key transmission unit 15 of the content transmission device 10 (step S1). For example, the work key Kw is updated in accordance with the billing payment cycle of the content usage fee, and the work key Kw is encrypted and transmitted to the portable terminal 20 in response to the update.

  When the scramble unit 11 of the content transmitting apparatus 10 acquires content, generation of the scramble key Ks is started. Each time the scramble key Ks is generated, the scramble unit 11 of the content transmitting apparatus 10 encrypts the content with the generated scramble key Ks. The work key encryption unit 12 of the content transmission device 10 generates the work key Kw when the scramble unit 11 of the content transmission device 10 generates the scramble key Ks. Then, the work key encryption unit 12 of the content transmission device 10 encrypts the scramble key Ks generated by the scramble unit 11 of the content transmission device 10 with the generated work key Kw. Usually, the scramble key Ks is included in the ECM, and the work key encryption unit 12 encrypts the ECM including the scramble key Ks. The multiplex transmission unit 13 of the content transmission device 10 multiplexes the encrypted content and the encrypted ECM, and transmits the multiplexed content to the content reception device 30 as a digital broadcast wave (step S2).

  The demultiplexing unit 31 of the content receiving device 30 separates the encrypted scramble key Ks from the digital broadcast wave received from the content transmitting device 10, and transmits the separated scramble key Ks to the mobile terminal 20 (step S3).

  The work key decryption unit 21 of the mobile terminal 20 decrypts the encrypted work key Kw received from the content transmission device 10 with the master key Km stored in the storage unit, and acquires the work key Kw. The scramble key decryption unit 22 of the mobile terminal 20 decrypts the encrypted scramble key Ks received from the content reception device 30 with the acquired work key Kw, and transmits the scramble key Ks to the content reception device 30 (step). S4).

  The descrambling unit 32 of the content receiving device 30 decrypts the encrypted content separated from the digital broadcast wave received by the demultiplexing unit 31 from the content transmitting device 10 with the scramble key Ks received from the mobile terminal 20, and displays the display. Etc. to be reproduced as content.

  As described above, according to the present embodiment, one or more content receiving apparatuses that can be operated on a mobile terminal by acquiring a scramble key for decrypting the content from a digital broadcast wave including the content in the mobile terminal. Viewing or recording reservations for the same or different contents can be realized at the same time. In addition, it is possible to determine whether or not the content can be viewed on the mobile terminal. Further, by including the number of content receiving devices that can be viewed and the viewing time in the contract information, it is possible to collectively control content viewing on each of the one or more content receiving devices on the mobile terminal.

  The conditional access system of the present invention is recorded by recording the processing of the conditional access system on a computer-readable recording medium, and causing each device constituting the conditional access system to read and execute the program recorded on the recording medium. Can be realized. The computer system here includes an OS and hardware such as peripheral devices.

  Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW (World Wide Web) system is used. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

  The embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiments, and includes designs and the like that do not depart from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Conditional reception system 10 Content transmission apparatus 11 Scramble part 12 Work key encryption part 13 Multiplex transmission part 14 Master key encryption part 15 Key transmission part 20 Portable terminal 21 Work key decryption part 22 Scramble key decryption part 23 Viewing judgment part 24 master key storage unit 30 content receiving device 31 demultiplexing unit 32 descrambling unit

Claims (5)

A limited reception system comprising a content transmission device, one or more content reception devices, and a portable terminal that operates the one or more content reception devices,
The content transmission device includes:
A scramble means for encrypting the content with a scramble key;
A work key encryption unit that encrypts the scramble key with a work key that is a key unique to the content transmission device, and creates common information obtained by encrypting at least common information about the content with the work key;
First transmission means for multiplexing the encrypted content , the encrypted scramble key , and the encrypted common information , and transmitting the multiplexed information to each of the one or more content reception devices;
The contract information including the work key encrypted with a master key that is unique to the content receiver, and viewing permission information for determining whether the content can be viewed and viewing control information for the one or more content receiving devices. And master key encryption means for creating individual information encrypted with the master key;
Second transmission means for transmitting the encrypted work key and the encrypted individual information to the portable terminal;
With
The portable terminal is
A work key for decrypting the encrypted work key and the encrypted individual information received from the content transmission device with the preset master key, and obtaining the work key and the contract information Decryption means;
A scramble for decrypting the encrypted scramble key and the encrypted common information received from each of the one or more content receivers with the work key, and obtaining the scramble key and the common information related to the content Key decryption means;
Based on the common information related to the content acquired by the scramble key decryption means and the view permission information for determining whether or not the content included in the contract information acquired by the work key decryption means, Based on the common information related to the content and the viewing control information for the one or more content receiving devices included in the contract information, the content viewing for the one or more content receiving devices is determined. Viewing judgment means for determining control;
A third transmission unit configured to transmit the scramble key to the one or more content reception devices according to the viewing control determined by the viewing determination unit when the viewing determination unit determines that the content can be viewed ;
With
Each of the one or more content receiving devices is
Received from the content transmitting apparatus, the scramble key and the encrypted common information the encrypted, and fourth transmission means for transmitting to said portable terminal,
Descrambling means for receiving a scramble key from the portable terminal and decrypting the encrypted content received from the content transmission device with the received scramble key;
A conditional access system comprising: The portable terminal includes an input unit that receives an operation input from a user,
The scramble key decrypting means scrambles the content receiving apparatus in which content selection has been performed in response to receiving an input of content selection by the user for each of the one or more content receiving apparatuses via the input means. The conditional access system according to claim 1, wherein the key is transmitted. The conditional access system according to claim 1 , wherein the portable terminal acquires the master key through communication with the content transmission device . A limited reception method in a limited reception system comprising a content transmission device, one or more content reception devices, and a portable terminal that operates the one or more content reception devices,
The content transmission device encrypts a work key, which is a key unique to the content transmission device, with a master key, which is a key unique to the content receiver, and viewing availability information for determining whether the content can be viewed; Creating individual information obtained by encrypting contract information including viewing control information for the one or more content receiving devices with the master key, and transmitting the encrypted work key and the encrypted individual information to the portable terminal. 1 step,
The content transmitting device multiplexes the content encrypted with the scramble key, the scramble key encrypted with the work key, and the common information obtained by encrypting at least common information related to the content with the work key, and A second step of transmitting to each of the content receiving devices;
A third step in which each of the one or more content reception devices transmits the encrypted scramble key received from the content transmission device and the encrypted common information to the mobile terminal;
The mobile terminal decrypts the encrypted work key and the encrypted individual information received from the content transmission device with the preset master key, and the work key and the contract information And a fourth step of obtaining
The mobile terminal uses the work key to decrypt the encrypted scramble key and the encrypted common information received from each of the one or more content receivers, and the scramble key and the common information related to the content And a fifth step of obtaining
The portable terminal includes common information related to the content acquired in the fifth step and viewing permission / prohibition information for determining whether or not to view the content included in the contract information acquired in the fourth step. Based on the common information related to the content and the viewing control information for the one or more content reception devices included in the contract information, the content for the one or more content reception devices is determined. A sixth step of determining content viewing control;
When it is determined that the content can be viewed in the sixth step, the mobile terminal transmits the scramble key to the one or more content reception devices according to the viewing control determined in the sixth step. A seventh step;
The conditional access method characterized by including. A program for causing a computer to execute a limited reception method in a limited reception system including a content transmission device, one or more content reception devices, and a portable terminal that operates the one or more content reception devices,
The content transmission device encrypts a work key, which is a key unique to the content transmission device, with a master key, which is a key unique to the content receiver, and viewing availability information for determining whether the content can be viewed; Creating individual information obtained by encrypting contract information including viewing control information for the one or more content receiving devices with the master key, and transmitting the encrypted work key and the encrypted individual information to the portable terminal. 1 step,
The content transmitting device multiplexes the content encrypted with the scramble key, the scramble key encrypted with the work key, and the common information obtained by encrypting at least common information related to the content with the work key, and A second step of transmitting to each of the content receiving devices;
A third step in which each of the one or more content reception devices transmits the encrypted scramble key received from the content transmission device and the encrypted common information to the mobile terminal;
The mobile terminal decrypts the encrypted work key and the encrypted individual information received from the content transmission device with the preset master key, and the work key and the contract information And a fourth step of obtaining
The mobile terminal uses the work key to decrypt the encrypted scramble key and the encrypted common information received from each of the one or more content receivers, and the scramble key and the common information related to the content And a fifth step of obtaining
The portable terminal includes common information related to the content acquired in the fifth step and viewing permission / prohibition information for determining whether or not to view the content included in the contract information acquired in the fourth step. Based on the common information related to the content and the viewing control information for the one or more content reception devices included in the contract information, the content for the one or more content reception devices is determined. A sixth step of determining content viewing control;
When it is determined that the content can be viewed in the sixth step, the mobile terminal transmits the scramble key to the one or more content reception devices according to the viewing control determined in the sixth step. A seventh step;
A program that causes a computer to execute.

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