JPWO2009057627A1 - Receiver - Google Patents

Abstract

The receiving apparatus 100 detects a reception unit 5 that receives a stream including a data signal, a signal separation unit 7 that separates a data signal from the stream received by the reception unit 5, and an update of the data signal separated by the signal separation unit 7. And an authentication unit 18 that authenticates the transmission source of the stream when an update of the data signal is detected by the update detection unit 16.

Description

Cross-reference of related applications

  This application claims the priority of Japanese Patent Application No. 2007-282328 filed on Oct. 30, 2007, the entire disclosure of which is hereby incorporated by reference.

  The present invention relates to a receiving apparatus that receives a stream including a data signal.

  In recent years, television broadcasting has become multi-channel due to the spread of digital broadcasting, and many program contents can be broadcast to viewers. Also in the Internet environment, with the spread of the high-speed Internet, services for distributing moving image content are increasing.

  There is a case where attached data (for example, data broadcasting in digital broadcasting) consisting of data signals is added to content distributed by such content distribution services such as digital broadcasting and the Internet. The attached data includes, for example, a script that executes an application program such as e-mail (hereinafter simply referred to as “application”) or writes data to a memory, an external URL (Internet address), or the like. Sometimes a jumping link is included.

  For this reason, in the content distribution service, it is necessary to guarantee the safety of the content to be distributed to the viewing user. Otherwise, even if the user receives a stream of legitimate content, it will be replaced by an unintended stream by a malicious attacker in the middle, and an illegal stream containing packets whose relationship between before and after cannot be guaranteed will be received. It is also possible.

  For example, in digital broadcasting, there is a risk of receiving an illegal stream in which data broadcasting capable of two-way communication is tampered with image data and audio data being the original broadcasting. In such a case, the user may believe that it is safe information provided by a reliable broadcasting station and execute an application included in the data broadcast, jump to a link destination, or the like. As a result, there is a possibility that the user may suffer serious actual damage such as a phishing scam, viewing / recording reservation information being rewritten, or undesired data being written in the nonvolatile memory. Furthermore, it is conceivable that a malicious and illegal script is automatically executed without the user determining whether or not the data broadcast stream is safe.

  In particular, recently, a form in which content is locally distributed by so-called one-segment broadcasting (one-segment partial reception service for mobile phones and mobile terminals) has also appeared. For example, a device such as a gap filler that is originally used to improve reception characteristics in areas and places where radio waves are difficult to reach has been proposed. In addition, a technology such as a one-segment broadcasting device using weak radio waves that can easily distribute different one-segment video contents to a plurality of narrow areas has been proposed.

  If such a local content distribution system becomes widespread and is used by a malicious person, the risk of falsified illegal broadcasting is further increased. It is thought that it will occur more frequently. Therefore, in digital broadcasting, a technique for determining whether or not data constituting a content stream is authentic is extremely important.

  For example, Japanese Patent Application Laid-Open No. 2003-154707 proposes that the broadcasting station side broadcasts by adding authentication data created based on the content to the content. . The content receiving apparatus that receives the broadcast performs authentication processing when acquiring the authentication data, and stops the reproduction processing of the content when authentication is not possible.

  According to the receiving apparatus described in Japanese Patent Application Laid-Open No. 2003-154707, content reproduction is performed only after authentication data can be authenticated. For this reason, it is avoided that a user who is viewing a digital broadcast using a receiving apparatus undesirably receives and views content that cannot be authenticated, such as illegal content.

  However, the receiving device described in Japanese Patent Application Laid-Open No. 2003-154707 does not always ensure communication quality, as in the case of a mobile terminal such as a mobile phone capable of viewing one-seg broadcasting, but rather In situations where packet loss or the like frequently occurs, authentication data cannot be authenticated. For this reason, there is a possibility that viewing is restricted even for broadcasting by regular contents.

  For example, as shown along the passage of time from the left to the center of the time chart of FIG. 13, for example, data broadcast A, which is a regular broadcast included in one-segment broadcasting, together with authentication data transmitted at a predetermined interval Consider the case of receiving at the receiver. In the method disclosed in Japanese Patent Application Laid-Open No. 2003-154707, a data broadcast reproduction process is performed when authentication of authentication data is successful, and a content reproduction process is stopped when authentication of authentication data fails. Is going. However, when the receiving device is a portable terminal, packet loss may frequently occur as shown in FIG. 13 due to factors such as the strength of radio waves at the receiving location. Therefore, when such a packet loss occurs, the authentication data cannot be authenticated, and the content reproduction process is stopped even if the stream is a regular broadcast until the authentication is successful with the next authentication data. Become. Accordingly, content viewing (data broadcasting displayed on the screen) during that time is limited.

  In order to cope with this problem, for example, it is conceivable to perform control so that the second and subsequent authentications are not performed for a broadcast stream that has been successfully authenticated once. However, in this case, as shown with the passage of time from the center to the right in FIG. 13, for example, after successful authentication of data broadcast A, which is a regular broadcast, it is an illegal broadcast that does not include authentication data. A problem arises when an unauthorized process such as switching to data broadcasting C is performed. That is, once the authentication is successful, the authentication process is not performed. Therefore, the unauthorized data broadcast C is not determined to be unauthorized, and the unauthorized content reproduction process is not stopped. In such a situation, an undesired operation is performed by executing a function such as an unauthorized script included in an unauthorized data broadcast stream. As a result, the user may suffer damage such as phishing scams and cannot safely use digital broadcast content.

  Therefore, an object of the present invention made in view of such circumstances is to provide a receiving apparatus that can safely use content based on a data signal without impairing user convenience.

The invention of the receiving apparatus according to the first aspect to achieve the above object is as follows:
A receiving unit for receiving a stream including a data signal;
A signal separator for separating a data signal from the stream received by the receiver;
An update detection unit for detecting an update of the data signal separated by the signal separation unit;
When update of the data signal is detected by the update detection unit, an authentication unit that performs authentication of the transmission source of the stream;
It is characterized by providing.

The invention according to the second aspect is the receiving apparatus according to the first aspect,
Until the authentication of the transmission source of the stream is successful by the authentication unit, the control unit further includes a control unit for controlling execution of a predetermined function based on the updated data signal.

The invention according to a third aspect is the receiving apparatus according to the second aspect,
The control unit prohibits execution of a predetermined script included in the data signal.

The invention according to a fourth aspect is the receiving apparatus according to the second aspect,
The control unit prohibits execution of an external link included in the data signal.

The invention according to a fifth aspect is the receiving apparatus according to the first aspect,
A storage unit for storing the data signal separated by the signal separation unit;
A display unit for performing display based on the stream;
Until the authentication of the transmission source of the stream is successfully performed by the authentication unit, storage of the updated data signal in the storage unit and display on the display unit based on the updated data signal are prohibited. A control unit to control;
Is further provided.

Furthermore, an invention according to a sixth aspect is the receiving apparatus according to the first aspect,
A storage unit having an unauthenticated area for storing a data signal for which authentication of the transmission source of the stream has not been successfully performed by the authentication unit; and an authenticated area for storing a data signal for which authentication of the transmission source of the stream has been successful. ,
A display unit for performing display based on a data signal stored in the authenticated area of the storage unit;
When an update of the data signal is detected by the update detection unit, the updated data signal is stored in an unauthenticated area of the storage unit, and when the authentication of the transmission source of the stream is successful by the authentication unit, A control unit for controlling the data signal stored in the unauthenticated area to move to the authenticated area;
Is further provided.

It is a functional block diagram of the receiver which concerns on 1st Embodiment of this invention. It is a figure which shows the example of the script command which should restrict execution before attestation success in 1st Embodiment. It is a flowchart explaining operation | movement of the receiver which concerns on 1st Embodiment. It is a time chart explaining operation | movement of the receiver which concerns on 1st Embodiment. It is a time chart explaining operation | movement of the receiver which concerns on 1st Embodiment. It is a flowchart explaining operation | movement of the receiver which concerns on 2nd Embodiment. It is a time chart explaining operation | movement of the receiver which concerns on 2nd Embodiment. It is a time chart explaining operation | movement of the receiver which concerns on 2nd Embodiment. It is a functional block diagram of the receiver which concerns on 3rd Embodiment. It is a flowchart explaining operation | movement of the receiver which concerns on 3rd Embodiment. It is a time chart explaining operation | movement of the receiver which concerns on 3rd Embodiment. It is a time chart explaining operation | movement of the receiver which concerns on 3rd Embodiment. It is a time chart explaining operation | movement of the conventional receiver.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control part 2, 4 Antenna 3 Radio | wireless part 5 Tuner part 6 Demodulation part 7 Separation part 8 Audio processing part 9 Video processing part 10 Data processing part 11 Audio | voice output part 12 Display part 13 Voice input part 14 Storage part 15 Operation key part 16 Update processing unit 17 Data broadcast reproduction control unit 18 Authentication unit 31 Unauthenticated area 32 Authenticated area

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of a main part of the receiving apparatus according to the first embodiment of the present invention. The receiving apparatus 100 of the present embodiment is a mobile communication terminal in which a mobile phone terminal capable of network communication to the Internet is equipped with a TV receiving function for viewing so-called one-segment broadcasting, which is terrestrial digital TV broadcasting. be able to. The receiving apparatus 100 includes a control unit 1 that controls the whole, a communication line antenna 2 and a radio unit 3 that constitute a radio communication unit, and a broadcast reception antenna 4 that constitutes a reception unit that receives digital terrestrial broadcasting. And a tuner unit 5.

  The radio unit 3 modulates voice information, e-mail, and the like processed by the control unit 1 and transmits them wirelessly from the antenna 2 to a base station (not shown), and is also transmitted from the base station by radio and received by the antenna 2. Various information such as mail, voice information, and data for web browser is demodulated and sent to the control unit 1.

On the other hand, the tuner unit 5 selects a broadcast reception signal received by the antenna 4 under the control of the control unit 1.
The demodulator 6 demodulates the broadcast reception signal thus selected, extracts a transport stream (TS) packet that is broadcast data, and supplies the transport stream (TS) packet to the separator 7. The separating unit 7 separates the supplied packet into an audio processing unit 8, a video processing unit 9, and a data processing unit 10 according to the packet ID. The audio processing unit 8 decodes the separated audio information and outputs the decoded audio information to the audio output unit 11, and the audio output unit 11 outputs the audio of the digital broadcast. The video processing unit 9 and the data processing unit 10 decode and process the separated video information and data for data broadcasting, respectively, and then display them on the display unit 12.

  Furthermore, the receiving device 100 includes a voice input unit 13 composed of a microphone for inputting voice of a call, a storage unit 14 that stores various data, and an operation key unit 15 that receives an operation of the receiving device 100 by a user. ing. The storage unit 14 stores a program for executing various applications, viewing reservation data, a schedule, an address, and the like, and secures a work area for executing the program and the like for data broadcasting included in the digital broadcasting stream. Data is also retained. The operation key unit 15 includes various operation keys such as a numeric keypad and direction keys including mechanical keys and touch panel keys. A selection key for selecting an element (notation name) for executing a script of a function displayed on the display unit 12 by data broadcasting included in the one-segment broadcasting is assigned to a predetermined operation key constituting the operation key unit 15.

  The data processing unit 10 includes an update detection unit 16 and a data broadcast reproduction control unit 17. The update detection unit 16 detects update of the data broadcast by acquiring update information of the data for data broadcast separated by the separation unit 7, and returns the result to the control unit 1. The data broadcast reproduction control unit 17 controls the display unit 12 to reproduce the data broadcast based on the data broadcast data stored in the storage unit 14. Further, the control unit 1 includes an authentication unit 18 that performs authentication processing by detecting authentication data included in a digital broadcast stream.

  In general, in data broadcasting in digital broadcasting, a broadcasting station transmits data to a receiving device for a predetermined period based on the DSM-CC (Digital Storage Media Command and Control) data carousel specification internationally standardized as ISO / IEC13818-6. On the other hand, the same data is repeatedly transmitted. During the repetition period, the same data broadcast is generally displayed on the display unit of the receiving apparatus.

  In the data carousel specification, data is transmitted using a DDB (Download Data Block) message that is a data body of data broadcasting and a DII (Download Info Indication) message that belongs to a DSM-CC control message. Among various fields included in the data structure of the DII message, there are fields of download identification (downloadId) and module version (moduleVersion). In these fields, the data broadcast is updated by updating the data event identification (data_event_id) encoded in the upper 4 bits of the download identification field (32 bits) and the value of the 8-bit module version. Show. The update of the data event identification value means an update of the entire content of the data broadcast, and the update of the module version value means an update of a part of the module constituting the content of the data broadcast. Hereinafter, the download identification and module version values are referred to as “update information” as appropriate.

  When viewing of the digital broadcast is started based on the operation of the operation key unit 15 or the like by the user, the receiving apparatus 100 according to the present embodiment starts to receive data broadcast data (DDB message). Store in the storage unit 14. When a set of data broadcast data constituting the content is stored in the storage unit 14, the content of the data broadcast can be displayed on the display unit 12. Thereafter, when the data broadcast is updated, the receiving apparatus 100 acquires update information of the data broadcast included in the DII message, and stores a set of data (DDB message) of the data broadcast updated based on the update information. Store in unit 14. Accordingly, the receiving device 100 reads the updated content of the data broadcast from the storage unit 14 and displays it on the display unit 12.

  When the data broadcast data is stored in the storage unit 14, the receiving device 100 inputs to the operation key unit 15 when the stored data broadcast includes a script or link information for executing a predetermined function. The function corresponding to each script and link information is executed based on or automatically.

  In the present embodiment, when the update detection unit 16 detects a change in the value of the data event identification or module version that is update information included in the DII message, the control unit 1 determines that the data broadcast has been updated, and the update The reception and acquisition of the data broadcast data is started. On the other hand, when a predetermined script command is included in the updated data broadcast stored in the storage unit 14, the control unit 1 performs control so as not to execute the script command. The script command for restricting execution is determined in advance as, for example, a script command (function name) shown in FIG.

  When the data broadcast data set constituting one content is stored in the storage unit 14, the data broadcast reproduction control unit 17 controls the display unit 12 to display the data broadcast. However, at this point in time, since the authentication of the data broadcast has not been successful, the control unit 1 keeps the execution of the predetermined function by the script command included in the data broadcast restricted.

  As described above, when the execution of the predetermined function is restricted by controlling not to execute the script command, the control unit 1 automatically executes the predetermined script command regardless of before and after the data broadcast is displayed on the display unit 12. It is controlled so that it will not be executed. Further, if the data broadcast is displayed on the display unit 12, the control unit 1 displays only the restricted function display portion on the display unit 12 when displaying the function of the script whose execution is restricted. It can be prevented. Alternatively, the function of the script whose execution is restricted may be displayed, but the user may not be able to select the location with the operation key unit 15. In addition, the script functions whose execution is restricted are displayed as selectable as usual, and when the user selects the location, “Data broadcasting is unauthenticated and the function is being restricted” or “Data broadcasting is not authorized. For this reason, it may be displayed that the execution of the function is pending. In this way, the user can know that the execution of the predetermined function is restricted.

  When the authentication unit 18 performs a process of authenticating whether the data broadcast data included in the stream is data transmitted from a legitimate transmission source, the digital broadcasting broadcast station converts predetermined authentication data into the stream. Transmit after adding at a predetermined interval. For this authentication data, for example, data as described in JP-A-2003-154707 can be added.

  When the update detection unit 16 detects the update information of the data broadcast, the control unit 1 controls the authentication unit 18 to authenticate the authentication data received after the update information of the data broadcast is detected. When this authentication fails, the control unit 1 keeps the execution of a predetermined function restricted until the authentication unit 18 succeeds in authenticating the subsequent authentication data. Once the authentication unit 18 successfully authenticates the authentication data, if there is a restricted function, the control unit 1 can execute a script command for that function.

  Since the data broadcast data necessary for displaying on the display unit 12 for a predetermined period is stored in the storage unit 14, the control unit 1 stores the data broadcast in the storage unit 14 until the next data broadcast is updated. The data broadcasting data being read is appropriately read and displayed on the display unit 12. Even after successful authentication, authentication data is added to the stream and transmitted at predetermined intervals. However, for a data broadcast that has been successfully authenticated once, the control unit 1 does not acquire and authenticate authentication data until the next data broadcast is updated (until the update detection unit 16 detects update information). The authentication unit 18 is controlled.

  Next, with reference to the flowchart of FIG. 3, a digital broadcast receiving operation by the receiving apparatus 100 according to the present embodiment will be described.

  In step S101, when an operation for selecting a digital broadcast and starting viewing is performed based on an operation of the operation key unit 15 or the like, the receiving apparatus 100 starts receiving the digital broadcast (step S102). Next, in step S103, the control unit 1 turns on the “update flag” when the mode is changed to the mode for displaying the digital broadcast data broadcast by the operation of the operation key unit 15 by the user or the environment setting (or initial setting). (Step S104). The “update flag” is a flag for starting the authentication process when the authentication unit 18 receives the above-described authentication data. In step S104, since the data broadcast data is not stored in the storage unit 14 since it is immediately after the start of viewing of the digital broadcast, the control unit 1 newly acquires all data broadcast data and stores it in the storage unit 14. Control is made to store (step S105).

  In step S106, the update detection unit 16 determines whether or not an update of the data broadcast is detected based on a change in the update information (data event identification or module version value). Immediately after starting to watch the digital broadcast, there is no update at the time when data for data broadcasting is newly acquired, and the process proceeds to step S109. On the other hand, when the update of the data broadcast is detected in step S106 during the viewing after the start of the viewing of the digital broadcast, the control unit 1 turns on the update flag described above (step S107). Then, the control unit 1 performs control so as to acquire updated data broadcast data based on the detected update information (step S108).

  Next, in step S109, the control unit 1 determines whether or not the update flag is on. At this time, if the update flag is on immediately after the start of viewing of the digital broadcast or after the detection of the update while viewing the data broadcast, the control unit 1 starts execution restriction of the predetermined function described above. At the same time, the contents of the data broadcast stored in the storage unit 14 are controlled to be displayed on the display unit 12 (step S110). At the same time, when the update flag is on, the control unit 1 controls the authentication unit 18 to acquire the authentication data and perform the authentication process.

  In step S111, when the authentication unit 18 can acquire the authentication data included in the digital broadcast stream, the authentication unit 18 authenticates the transmission source of the acquired authentication data (step S112). If authentication of the authentication data is successful in step S113, that is, if it is confirmed that the transmission source of the received digital broadcast stream is a regular transmission source, the control unit 1 turns off the update flag. (Step S114). After turning off this update flag, the control unit 1 releases the execution restriction of the predetermined function and enables execution of the script command. Note that even if the next authentication data is received while the update flag is off, the authentication unit 18 does not acquire and authenticate the authentication data.

  After the update flag is turned off in step S114, the process proceeds to step S115, and as long as the mode for displaying the data broadcast continues, the process returns to step S106 to continue the process. If the authentication unit 18 fails to authenticate the authentication data in step S113, a message indicating that the authentication has failed is displayed on the display unit 12 (step S116), and the update flag remains on, that is, a predetermined function. The process proceeds to step S115 while restricting the execution of.

  If the update flag is not turned on, that is, turned off in step S109, that is, if the authentication data has been successfully authenticated once and update information of the data broadcast has not been detected thereafter, the process proceeds to step S117. Migrate to In step S117, the control unit 1 controls the data broadcast data already acquired to be read from the storage unit 14 and displayed on the display unit 12 without restricting execution of a predetermined function, and the process proceeds to step S115. To do.

  As described above, in the present embodiment, for example, as shown along the passage of time from the left to the center of FIG. 4, a regular data broadcast whose transmission source has been successfully authenticated once after the start of viewing of the digital broadcast is started. For (data broadcasting A), the authentication process is not performed until the next update information is detected, and execution of a predetermined function is not limited. Therefore, even if authentication data transmitted at a predetermined interval is lost due to packet loss or the like as shown in FIG. 4, for example, execution of a predetermined function is not restricted. For this reason, the inconvenience that execution of a predetermined function is restricted despite data broadcasting transmitted from a regular broadcasting station is solved.

  4, when the received data broadcast is updated from the data broadcast A to the data broadcast B, as shown along the passage of time from the center to the right in FIG. As soon as is stored in the storage unit 14, display on the display unit 12 is started. However, the receiving device 100 limits the execution of a predetermined function at the same time as detecting update information. Therefore, when the updated data broadcast B is an illegal data broadcast by impersonation, for example, the risk of executing a malicious script command or link information is eliminated. Thereafter, the receiving apparatus 100 acquires and authenticates the authentication data after the update information is detected, and displays the data broadcast until the authentication is successful, but is limited to executing a predetermined function. Leave it on.

  When the updated data broadcast B is also a data broadcast transmitted from a regular transmission source, once the authentication by the regular authentication data is successful, the restriction on the predetermined function is released, and then the next data broadcast is performed. Authentication is not performed until update information is detected. Therefore, as compared with the case where authentication is performed every time authentication data is received, the processing load of the receiving apparatus 100 is significantly reduced, and power consumption can be suppressed.

  Further, as shown in FIG. 5, a case where the received data broadcast is switched from a regular data broadcast (data broadcast A) to an unauthorized data broadcast (data broadcast C) that does not include authentication data will be considered. In this case, the updated data broadcast is displayed on the display unit 12 immediately after the update, but the execution of a predetermined function is restricted at the same time as the update information is detected. After that, until the successful authentication is obtained and the authentication is successful, the unauthorized data broadcast is displayed, but the execution restriction is still applied to the specified function. There is no risk of executing.

  When the update detection unit 16 detects the update of the module version value instead of the data event identification value as the update information of the data broadcast, that is, the entire content constituting the data broadcast is not updated. It is also assumed that only the modules are updated. In this case, it is preferable to limit the execution of only the functions related to the updated module. By doing so, some modules were updated while executing functions based on script commands and links included in the data broadcast once successfully authenticated. There is no restriction on the execution of all of the predetermined functions until successful. Therefore, the inconvenience that the function already executed is suddenly restricted until the authentication is successful is eliminated.

  As described above, in the present embodiment, the stream transmission source authentication process is performed only when the data broadcast is updated, and the predetermined script included in the data broadcast is updated after the data broadcast is updated. Do not execute instructions or links. For this reason, the user can use the content by data broadcasting safely, without impairing convenience.

(Second Embodiment)
Next, a receiving apparatus according to the second embodiment of the present invention will be described. In the receiving apparatus according to the first embodiment described with reference to FIG. 1, the receiving apparatus according to the present embodiment restricts execution of a predetermined function even if the update detection unit 16 detects update information of a data broadcast. There is no control.

  For this reason, in this embodiment, when the update detection unit 16 detects update information, the authentication unit 18 acquires and authenticates authentication data included in the stream. Further, until the authentication data is successfully authenticated, the storage unit 14 does not store the data broadcast data even if the updated data broadcast data is received.

  From the time when the authentication unit 18 succeeds in authenticating the authentication data, the control unit 1 performs control so that the updated data broadcast data is acquired and stored in the storage unit 14. When the updated data broadcast data set is stored in the storage unit 14, the control unit 1 reads the updated data broadcast content from the storage unit 14 and displays it on the display unit 12. Thereafter, the authentication unit 18 does not perform the authentication process until the update detection unit 16 detects the next update information. Other operations are the same as those in the first embodiment.

  Next, with reference to the flowchart of FIG. 6, a digital broadcast receiving operation by the receiving apparatus 100 according to the present embodiment will be described.

  In step S201, when a digital broadcast is selected and an operation for starting viewing is performed, the receiving apparatus 100 starts receiving the digital broadcast (step S202). Next, when shifting to the mode for displaying the data broadcast in step S203, the control unit 1 turns on the “update flag” described in the first embodiment (step S204).

  Next, in step S205, it is determined whether there is data broadcast data that has already been acquired and stored in the storage unit. Immediately after starting the reception of data of the data broadcast, there is no data broadcast data stored in the storage unit 14, so the control unit 1 informs the display unit 12 that “data broadcasting data is being authenticated” or A message such as “acquiring data for data broadcasting” is displayed (step S206). When the digital broadcast is already viewed in step S205 and the authentication of the authentication data included in the stream is once successful, the data broadcast data after the successful authentication is acquired and stored. 14 is stored. In this case, the control unit 1 performs control so that the acquired data broadcasting data is read from the storage unit 14 and displayed on the display unit 12 (step S207).

  In step S208, the update detection unit 16 determines whether an update of the data broadcast has been detected based on a change in the update information. Since there is no update when data broadcasting data is newly acquired immediately after the start of viewing digital broadcasting, the process proceeds to step S210. On the other hand, if the update of the data broadcast is detected in step S208 while the digital broadcast is already being viewed, the control unit 1 turns on the update flag (step S209), and then proceeds to step S210. To do.

  In step S210, the control unit 1 determines whether or not the update flag is on. When the authentication data is received when the update flag is on (YES in step S211), the authentication unit 18 Then, the authentication process of the transmission source of the acquired authentication data is performed (step S212).

  When the authentication unit 18 succeeds in authenticating the authentication data in step 213, the updated data broadcast data is acquired based on the previously acquired update information and stored in the storage unit 14 (step S214). If the authentication performed in step S213 is the first authentication after viewing the digital broadcast, the data broadcasting data is acquired for the first time, so the data set constituting the data broadcast is obtained. Get all.

  When the data broadcast data is stored in step S214, the control unit 1 turns off the update flag (step S215). If the mode for displaying the data broadcast is continued in step 216, the control unit 1 reads the acquired data broadcast by referring to the storage unit 14 through NO in step S216 and YES in step S205. It displays on the display part 12 (step S207).

  In step S213, if the authentication unit 18 fails to authenticate the authentication data, the fact that the authentication has failed is displayed (step S217), and the process proceeds to step S216 while the update flag remains on.

  If the update flag is not on in step S210, that is, if the update flag is off, the authentication unit 18 proceeds to step S216 without acquiring and authenticating the authentication data even if it is received. If authentication data is not received in step S211, the update flag remains on and the process proceeds to step S216.

  As described above, in this embodiment, as in the first embodiment, for example, as shown along the passage of time from the left to the center in FIG. For the regular data broadcast (data broadcast A) that has been successfully authenticated, authentication processing is not performed until update information is next detected. Therefore, even if the authentication data transmitted at a predetermined interval is lost due to packet loss or the like as shown in FIG. 7, for example, the viewing of the data broadcast transmitted from the regular broadcasting station is caused. There is no inconvenience that the performance of a predetermined function based on data broadcasting is restricted. Therefore, this embodiment also has an effect that the processing load of the receiving apparatus 100 is significantly reduced and power consumption can be suppressed as compared with the case where authentication is performed every time authentication data is received.

  As shown in FIG. 7 along with the passage of time, when the received data broadcast is updated from the data broadcast A to the data broadcast B, the receiving apparatus 100 authenticates the authentication data included in the digital broadcast stream. Until successful, the acquisition of unauthenticated data broadcasting data or storage in the storage unit 14 is not performed. In the present embodiment, the control unit 1 does not perform control to limit the execution of a predetermined function based on a script command included in a data broadcast that has not been successfully authenticated, but unauthenticated data broadcast data is not As a result, the execution of these predetermined functions is limited. Therefore, also in the present embodiment, when the updated data broadcast B is an illegal data broadcast by impersonation, for example, the risk of executing a malicious script instruction is eliminated, and the first embodiment The same effect can be obtained.

  Furthermore, in the present embodiment, unauthenticated data broadcast data is not acquired. Therefore, even if the data broadcast is updated, the data broadcast is not displayed on the display unit 12 until the authentication is successful. Therefore, for example, as shown in FIG. 8 along with the passage of time, the received data broadcast is switched from the regular data broadcast (data broadcast A) to the unauthorized data broadcast (data broadcast C) that does not include authentication data. The authentication data is not successfully authenticated (authentication processing is not performed). For this reason, an unauthorized data broadcast is not displayed on the display unit 12. Therefore, in this embodiment, the risk of viewing unauthorized data broadcasting is also avoided.

(Third embodiment)
FIG. 9 is a block diagram showing a circuit configuration of a main part of a receiving apparatus according to the third embodiment of the present invention. The receiving apparatus 300 of this embodiment is obtained by changing the internal configuration of the storage unit 14 of the receiving apparatus 100 according to the first embodiment described with reference to FIG. The storage unit 14 of the receiving device 300 includes an unauthenticated area 31 and an authenticated area 32 therein. The unauthenticated area 31 is an area for temporarily storing data for data broadcasting that has not been successfully authenticated by the authentication data. The authenticated area 32 is an area where the data broadcasting data stored in the unauthenticated area 31 is transferred and stored after successful authentication of the transmission source by the authentication data.

  In the second embodiment described above, until the authentication data is successfully authenticated, control is performed so that the updated data broadcast data is not acquired or stored even if it is received. In the present embodiment, when the update detection unit 16 detects update information, the authentication unit 18 acquires and authenticates the authentication data included in the stream, while the storage unit 14 does not receive the updated data broadcast data. Store in the authentication area 31. Therefore, when the data broadcast data is updated, the control unit 1 acquires data for which authentication of the transmission source has not yet been successful, but uses unauthenticated data broadcast data stored in the unauthenticated area 31. Control is performed so that script commands and links are not read out and displayed on the display unit 12.

  After storing the updated data broadcasting data in the unauthenticated area 31, the control unit 1 is stored in the unauthenticated area 31 when the authenticating unit 18 acquires the authentication data and succeeds in the authentication. The updated data broadcast data is moved to the authenticated area 32. When the updated data broadcast data is moved to the authenticated area 32, the control unit 1 reads the updated data broadcast content from the authenticated area 32 and displays it on the display unit 12. Thereafter, the authentication process by the authentication unit 18 is not performed until the update detection unit 16 detects the next update information.

  Next, with reference to the flowchart of FIG. 10, a digital broadcast receiving operation by the receiving apparatus 300 according to the present embodiment will be described.

  In step S301, when a digital broadcast is selected and an operation for starting viewing is performed, the receiving apparatus 300 starts receiving the digital broadcast (step S302). Next, when the mode is changed to the mode for displaying the data broadcast in step S303, the control unit 1 turns on the “update flag” described above (step S304), and acquires all the data of the data broadcast newly. Is stored in the unauthenticated area 31 (step S305).

  Next, in step S306, it is determined whether or not the data broadcast data that has been acquired and has already been successfully authenticated is in the authenticated area 32. Immediately after starting the reception of data of the data broadcast, there is no data broadcast data stored in the authenticated area 32, so that the control unit 1 informs the display unit 12 that “data broadcasting data is being authenticated” or A message such as “acquiring data for data broadcasting” is displayed (step S307). When the digital broadcast is already viewed in step S306 and the authentication data included in the stream has been successfully authenticated once, the data broadcast data after the successful authentication is stored in the authenticated area 32. I remember it. In this case, the control unit 1 controls to read the authenticated data broadcast data from the authenticated area 32 and display it on the display unit 12 (step S308).

  In step S309, the update detection unit 16 determines whether an update of the data broadcast has been detected based on a change in the update information. Since there is no update when data broadcasting data is newly acquired immediately after the start of viewing digital broadcasting, the process proceeds to step S312. On the other hand, when the update of the data broadcast is detected in step S309 during the viewing after the start of the viewing of the digital broadcast, the control unit 1 turns on the update flag (step S310) and then based on the update information. Then, the updated data broadcast data is acquired and stored in the unauthenticated area 31 (step S311).

  In step S312, the control unit 1 determines whether or not the update flag is on. If the authentication data is received when the update flag is on (YES in step S313), the authentication unit 18 Then, the authentication processing of the transmission source of the acquired authentication data is performed (step S314).

  When the authentication unit 18 succeeds in authenticating the authentication data in step 315, the control unit 1 moves the data broadcast data that has been successfully authenticated, stored in the unauthenticated region 31, to the authenticated region 32 (step 315). S316).

  When the data broadcast data is moved to the authenticated area 32, the control unit 1 turns off the update flag (step S317). If the mode for displaying the data broadcast is continued in step 318, the control unit 1 reads the acquired data broadcast by referring to the authenticated area 32 through NO in step S318 and YES in step S306. Is displayed on the display unit 12 (step S308).

  If the authentication unit 18 fails to authenticate the authentication data in step S315, the fact that the authentication has failed is displayed (step S319), and the process proceeds to step S318 while the update flag remains on.

  If the update flag is not on in step S312, that is, if the update flag is off, the authentication unit 18 proceeds to step S318 without acquiring and authenticating the authentication data even if it is received. If authentication data has not been received in step S313, the update flag remains on and the process proceeds to step S318.

  As described above, in this embodiment, as in the first and second embodiments, for example, as shown along the passage of time from the left to the center of FIG. (Data broadcasting A) does not perform the authentication process until update information is detected next time. For this reason, even if authentication data transmitted at a predetermined interval is lost due to packet loss, for example, as shown in FIG. 11, viewing of data broadcasts transmitted from legitimate broadcasting stations is restricted. And there is no inconvenience that execution of a predetermined function based on data broadcasting is restricted. Therefore, this embodiment also has an effect that the processing load of the receiving apparatus 300 is significantly reduced and power consumption can be suppressed as compared with the case where authentication is performed every time authentication data is received.

  As shown in FIG. 11 along with the passage of time, when the received data broadcast is updated from the data broadcast A to the data broadcast B, the receiving device 300 immediately acquires the data of the updated data broadcast. Start. However, at this time, the unauthenticated data broadcast data is stored in the unauthenticated area 31 until the authentication of the authentication data included in the digital broadcast stream is successful. In the present embodiment, the data broadcast data stored in the unauthenticated area 31 is not displayed on the display unit 12. For this reason, as in the first and second embodiments, if the updated data broadcast B is an illegal data broadcast by impersonation, for example, a risk that a malicious script instruction or link is executed. Is resolved.

  Furthermore, in the present embodiment, receiving device 300 has already acquired and stored updated data broadcast data when authentication unit 18 succeeds in authenticating the authentication data. Therefore, the control unit 1 can immediately display the updated data broadcast data stored in the unauthenticated area 31 on the display unit 12 by moving it to the authenticated area 32. Therefore, in the present embodiment, after the regular data broadcast is successfully authenticated, the data broadcast can be displayed earlier than in the second embodiment.

  In the present embodiment, as described above, even if unauthenticated data broadcasting data is acquired, it remains in the unauthenticated area 31. Therefore, even if the data broadcasting is updated, until the authentication is successful. The data broadcast is not displayed on the display unit 12. That is, for example, as shown in FIG. 12 along with the passage of time, the received data broadcast is switched from a regular data broadcast (data broadcast A) to an unauthorized data broadcast (data broadcast C) that does not include authentication data. The authentication is not successful (authentication process is not performed). For this reason, an unauthorized data broadcast is not displayed on the display unit 12. Therefore, also in this embodiment, the risk of viewing unauthorized data broadcasting is avoided.

  In addition, this invention is not limited to the said embodiment, Many deformation | transformation or a change is possible. For example, in each of the above-described embodiments, the authentication data transmitted from the broadcast station to the receiving apparatus is stream data (or a part thereof) using a hash function as in the authentication method described in Patent Document 1. ) Is obtained, and is added to the data as metadata and transmitted. In the present invention, the authentication data transmitted from the broadcasting station to the receiving device is arbitrary as long as it is authentication data that can be transmitted by being included in the stream at a predetermined interval and can authenticate the transmission source. It can be.

  According to the present invention, when an update of a data signal is detected, the source of the stream is authenticated to ensure safety against unauthorized broadcasting, and the next update is performed for the stream once authenticated successfully. Authentication processing is not performed until it is detected. Therefore, use of regular content is not hindered and user convenience is not impaired.

Claims (6)

A receiving unit for receiving a stream including a data signal;
A signal separator for separating a data signal from the stream received by the receiver;
An update detection unit for detecting an update of the data signal separated by the signal separation unit;
When update of the data signal is detected by the update detection unit, an authentication unit that performs authentication of the transmission source of the stream;
A receiving apparatus comprising:   The control unit according to claim 1, further comprising: a control unit that controls execution of a predetermined function based on the updated data signal until the authentication of the transmission source of the stream is successful by the authentication unit. The receiving device described in 1.   The receiving apparatus according to claim 2, wherein the control unit prohibits execution of a predetermined script included in the data signal.   The receiving apparatus according to claim 2, wherein the control unit prohibits execution of an external link included in the data signal. A storage unit for storing the data signal separated by the signal separation unit;
A display unit for performing display based on the stream;
Until the authentication of the transmission source of the stream is successfully performed by the authentication unit, storage of the updated data signal in the storage unit and display on the display unit based on the updated data signal are prohibited. A control unit to control;
The receiving device according to claim 1, further comprising: A storage unit having an unauthenticated area for storing a data signal for which authentication of the transmission source of the stream has not been successfully performed by the authentication unit; and an authenticated area for storing a data signal for which authentication of the transmission source of the stream has been successful. ,
A display unit for performing display based on a data signal stored in the authenticated area of the storage unit;
When an update of the data signal is detected by the update detection unit, the updated data signal is stored in an unauthenticated area of the storage unit, and when the authentication of the transmission source of the stream is successful by the authentication unit, A control unit for controlling the data signal stored in the unauthenticated area to move to the authenticated area;
The receiving device according to claim 1, further comprising:

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