WO2011013303A1 - Received-data authentication method and digital broadcast receiver - Google Patents

Abstract

Disclosed is a received-data authentication method which makes it possible, in a digital broadcast receiver, to simplify authentication processing performed for verifying the trustworthiness of an application requiring authentication, and thereby reduce the delay in display of the application. The method comprises: determining, on the basis of application identification information, whether a received application requiring authentication is an application received for the first time; and, when the received application requiring authentication is determined to not be an application received for the first time, executing authentication processing with respect to the received application requiring authentication as a whole.

Description

Received data authentication method and digital broadcast receiver

The present invention relates to a digital broadcast receiver used in a digital broadcast system and a received data authentication method for authenticating data received by the digital broadcast receiver.

In the digital broadcast receiver used in the digital broadcast system, when receiving an application for displaying various information such as interactive programs displayed on the screen in parallel with the video / audio data which is the data of the general broadcast program The application has been verified to confirm its credibility, such as whether the application has been tampered with or issued by a trusted organization. This verification is performed based on a standard described in the DVB-MHP standard document “EST TS 101 812 V1.2.1 DVB-MHP specification 1.0.2” or the like. As a result of this verification, programs that perform actions different from the original actions or programs of third parties pretending to be someone else, which may damage viewers in the digital broadcasting system, are started. This is to prevent this.

An authentication method for verifying the credibility of an MHP application when receiving an application conforming to the DVB-MHP standard (hereinafter abbreviated as an MHP application) in a digital broadcast receiver in a conventional digital broadcast system is disclosed in, for example, Patent Literature 1 is disclosed.

In the authentication method disclosed in Patent Document 1, the MHP application has a hierarchical structure including a root directory unit, a subdirectory unit, and a file unit. The file data acts according to the authentication algorithm, and the associated file authentication value is stored in the reference subdirectory unit. The file authentication value operates according to the authentication algorithm, and the associated subdirectory authentication value is stored in the reference root directory unit. In the conventional digital broadcasting system having the hierarchical structure configured as described above, the authentication of the modules in each layer is sequentially performed using the authentication algorithm in each layer, and the modules in each layer are not tampered. It was confirmed that it was issued by an institution capable of verifying the authenticity of the received MHP application.

Special table 2002-508624 gazette

In the conventional digital broadcast receiver, the authentication of the module of each layer is performed in each layer from the beginning every time in order to verify the reliability of the received MHP application. There was a problem that it took time to display. For example, when the MHP application A is displayed on the screen together with the video / audio data that is a general broadcast program in the first channel, the user selects the second channel, which is another channel, and immediately returns to the first channel. Even in such a case, in the conventional digital broadcast receiver, the authentication process for verifying the reliability of the MHP application A of the first channel is newly executed in all layers from the beginning. Further, even when the MHP application A by the first channel is displayed on the screen, the power is turned off, and the first channel is displayed even if the power is turned on immediately and the first channel is displayed. Authentication processing for the MHP application A has been performed all over again from the beginning.

As described above, in the conventional digital broadcasting receiver, the authentication process for verifying the credibility of the MHP application to be displayed is the same as the corresponding MHP application received in the past by the received MHP application. Even if it is not updated, since it is executed from the beginning every time it is displayed, there is a problem that the display of the MHP application is displayed with a delay from the display of the general broadcast program.
In the present invention, an authentication process for verifying the credibility of an application that needs to be authenticated in a digital broadcast receiver is reliably performed in a shorter time than before, and the display delay of the application is improved. It is aimed. It is an object of the present invention to realize a received data authentication method that can eliminate discomfort in using a digital broadcast receiver for a user, and to provide a digital broadcast receiver equipped with the received data authentication method. It is.

The received data authentication method according to the first aspect of the present invention includes:
A receiving step for receiving an application requiring authentication processing (hereinafter, abbreviated as an authentication application);
A determination step of determining whether the received authentication application is an application received for the first time based on application identification information;
In the determination step, when it is determined that the received authentication application is an application received for the first time, a hierarchy authentication calculation step for executing an authentication calculation process for each layer of the received authentication application,
If the calculated authentication value of each layer calculated in the hierarchical authentication calculation step is the same as the stored authentication value stored in the authentication file of the authentication application, the control unit determines that the received authentication application is a valid application And storing the authentication calculation result for the received authentication application as a whole storage authentication value in the storage unit,
In the determination step, when it is determined that the received authentication application is not an application received for the first time, an overall authentication calculation step for executing an authentication calculation process for the entire received authentication application,
A comparison step of comparing the calculated overall authentication value calculated by the authentication calculation process for the entire received authentication application with the stored overall authentication value for the entire past authentication application corresponding to the received authentication application;
A notification step of notifying the control unit that the received authentication application is a valid application when the calculated total authentication value matches the stored total authentication value. According to the received data authentication method of the first aspect of the present invention having such steps, the authentication operation for verifying the authenticity of the authentication application can be simplified and performed in a short time. The delay can be improved.

A received data authentication method according to a second aspect of the present invention is stored in the storage unit when the calculated total authentication value and the stored total authentication value do not match in the authentication method according to the first aspect. It further includes a deletion step of deleting the stored whole authentication value for the entire past authentication application corresponding to the received authentication application and shifting to the hierarchical authentication calculation step and the storage step.

The received data authentication method according to the third aspect of the present invention is the authentication method according to the first aspect, wherein the calculated overall authentication value for the received authentication application as a whole, together with the identification number of the received authentication application, Saved in the storage unit.

The received data authentication method according to the fourth aspect of the present invention is the authentication method according to the first aspect, wherein the calculated overall authentication value for the received authentication application as a whole is a unique authentication algorithm possessed by the digital broadcast receiver. In the comparison step, the calculated entire authentication value is calculated by the authentication algorithm using the unique authentication algorithm for the entire past authentication application corresponding to the received authentication application. It is compared with the processed whole storage authentication value.

The received data authentication method according to the fifth aspect of the present invention is the authentication method according to the fourth aspect, wherein, in the comparison step, the calculated overall authentication value for the entire received authentication application is the received authentication application. The area calculation authentication value calculated by the authentication calculation process for each authentication file belonging to each hierarchy area sequentially from the lowest hierarchy area, and the corresponding hierarchy when there is a mismatch with the stored overall authentication value for the entire corresponding past authentication application When the area authentication value comparison for comparing the area storage authentication value of the authentication file belonging to the area is performed and the mutual values match in the area authentication value comparison, the hierarchical area of the received authentication application is the past authentication application It is determined that no change has been made from the hierarchy area.

The received data authentication method according to the sixth aspect of the present invention is the authentication method according to the fourth aspect, wherein the calculated overall authentication value and the authentication value of the authentication file for the entire received authentication application are the received authentication application. And the identification number are stored in the storage unit.

A digital broadcast receiver according to a seventh aspect of the present invention is a digital broadcast receiver that receives an application requiring authentication processing (hereinafter abbreviated as an authentication application).
A receiving unit that receives the authentication application, an authentication processing unit that performs an authentication calculation process on the received authentication application, and
A storage unit for storing the result of the authentication calculation process;
A control unit that controls the entire digital broadcast receiver,
In the authentication calculation process in the authentication processing unit, an authentication value for the entire authentication application that has been authenticated in the past is calculated and stored in the storage unit as a stored overall authentication value. Configured to notify the control unit that the received authentication application is a legitimate application when the calculated total authentication value for the entire authentication application matches the stored total authentication value stored in the storage unit. ing. According to the digital broadcast receiver according to the seventh aspect of the present invention configured as described above, it is possible to perform an authentication operation for verifying the authenticity of the authentication application in a short time, and to delay the display of the authentication application. It can be improved, and discomfort in using the digital broadcast receiver for the user can be eliminated.

In the digital broadcast receiver according to the eighth aspect of the present invention, the authentication processing unit according to the seventh aspect includes an authentication determination unit and an authentication calculation processing unit,
The authentication determination unit receives an instruction from the control unit and notifies the authentication calculation processing unit of information related to the received authentication application,
The authentication calculation processing unit executes an authentication calculation process for the received authentication application as a whole, calculates a calculated overall authentication value,
In the authentication determination unit, the calculated overall authentication value is compared with the stored overall authentication value stored in the storage unit for the entire past authentication application corresponding to the received authentication application, When the comparison result between the calculated total authentication value and the stored total authentication value matches, the control unit is notified that the received authentication application is a valid application.

In the digital broadcast receiver according to the ninth aspect of the present invention, in the authentication processing unit according to the seventh aspect, the calculated overall authentication value for the entire received authentication application corresponds to the past corresponding to the received authentication application. If the total authentication value stored for the entire authentication application does not match, the area calculation authentication value calculated by the authentication calculation processing for each authentication file belonging to each hierarchical area sequentially from the lowest hierarchical area, and belongs to the hierarchical area When the area authentication value comparison for comparing the authentication value with the area storage authentication value of the authentication file is performed, and the mutual values match in the area authentication value comparison, the hierarchical area of the received authentication application is the hierarchical area of the past authentication application It is comprised so that it may determine with having not changed.

In the digital broadcast receiver according to the tenth aspect of the present invention, the calculated total authentication value and the authentication value of the authentication file for the entire authentication application received according to the seventh aspect together with the identification number of the received authentication application. It is comprised so that it may preserve | save at the said memory | storage part.

ADVANTAGE OF THE INVENTION According to this invention, the authentication process which verifies the reliability with respect to the application based on DVB-MHP standard which needs to perform the authentication process in a digital broadcast receiver can be reliably performed in a short time compared with the past. The display delay of the application can be improved, and the discomfort in using the digital broadcast receiver for the user can be eliminated.

1 is a block diagram showing a system configuration of a digital broadcast receiver according to a first embodiment of the present invention. FIG. 3 is a block diagram showing a configuration of an authentication processing unit and a data flow in the digital broadcast receiver according to the first embodiment. The figure which shows an example of the hierarchical structure of the MHP application received in the digital broadcasting receiver of Example 1. The figure which shows an example of the Index file in the digital broadcast receiver of Example 1. FIG. The flowchart which shows the authentication operation | movement when the digital broadcast receiver of Example 1 receives an MHP application. The figure which shows an example of the hierarchical structure of the MHP application received in the digital broadcast receiver of Example 2 which concerns on this invention, and demonstrates specific authentication operation | movement The figure which shows an example of the hierarchical structure of the MHP application received in the digital broadcast receiver of Example 2 which concerns on this invention, and demonstrates specific authentication operation | movement The figure which shows an example of the hierarchical structure of the MHP application received in the digital broadcast receiver of Example 2 which concerns on this invention, and demonstrates specific authentication operation | movement The figure which shows an example of the hierarchical structure of the MHP application received in the digital broadcast receiver of Example 2 which concerns on this invention, and demonstrates specific authentication operation | movement The figure which shows an example of application ID etc. which are preserve | saved in the Index file in the digital broadcast receiver of Example 2.

Hereinafter, preferred embodiments of a digital broadcast receiver and a received data authentication method used in a digital broadcast system according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a system configuration of the digital broadcast receiver according to the first embodiment. In the digital broadcast receiver 1 shown in FIG. 1, the transport stream (TS) in the MPEG2 format received by the antenna 11 is input to the tuner 12, and the TS of the channel selected by the user is demodulated. The TS includes video data, audio data, object carousel, AIT (Application Information Table), PAT (Program Association Table), PMT (Program Map Table), CAT (Conditional Access Table), and the like. The object carousel is a data structure / system for carrying data broadcast contents such as an application that needs to perform authentication processing, such as an MHP application (an application that conforms to the DVB-MHP standard). The MHP application is generally configured in a hierarchical structure with one root directory, at least one directory, and at least one file, and is transmitted as an object carousel. The MHP application provides information related to video / audio data indicating a general broadcast program to the user, and refers to an application that operates in an interactive Java (registered trademark) execution environment.

The TS selected by the tuner 12 is demodulated and input to the transport decoder (TD) 13. In the TD 13, the MPEG2 format TS input from the tuner 12 is decoded (filtered). In the TD 13, video / audio data indicating a general broadcast program of video data and audio data is output to the AV decoder 18, and data such as an object carousel and AIT is output to the CPU 14 which is a central processing unit. In the digital broadcast receiver 1 according to the first embodiment, the antenna 11, the tuner 12, and the TD 13 are used as a receiving unit.

In the digital broadcast receiver 1 according to the first embodiment, the CPU 14 serving as a control unit controls the entire operation of the digital broadcast receiver 1. For example, the CPU 14 causes the tuner 12 to select a predetermined channel corresponding to the key code input from the remote controller (remote controller) 2 via the remote controller receiver 21. As described above, the remote control receiver 21 receives operation information from the remote control 2 set by the user and outputs data as a key code to the CPU 14.

In the CPU 14, the identifier of the MHP application described in the AIT, the path to the file accessed first by the Java execution unit 17 (character string indicating the location), and the path to the root directory (indicating the location) The MHP application is extracted from the input object carousel based on the character string), and the MHP application is cached (stored) in the memory 15, and after authentication by the authentication processing unit 16, the MHP application is sent to the Java execution unit 17. The execution command is output.

The memory 15 serving as a storage unit in the first embodiment is configured by an HDD, but may be configured by a general storage unit configured by a general volatile / nonvolatile memory. In the memory 15, as described above, the MHP application is cached based on a command from the CPU 14. In addition, the memory 15 provides an MHP application stored in response to an MHP application read instruction from the Java execution unit 17. Note that the memory 15 stores data of authentication values and file paths (locations in the hierarchical structure of MHP applications) for each MHP application that are calculated by the authentication processing unit 16.

Upon receiving a command from the CPU 14, the authentication processing unit 16 performs authentication calculation processing for the MHP application, and records the authentication value and file path calculated by the authentication calculation processing in the memory 15.
The Java execution unit 17 is a Java (registered trademark) virtual machine in the DVB-MHP standard, and reads an MHP application instructed from the memory 15 in response to an execution command of the MHP application from the CPU 14. The MHP application read by the Java execution unit 17 is output to the synthesis circuit 19.

The AV decoder 18 decodes (decodes) the video data and audio data input from the TD 13 and outputs them to the synthesis circuit 19.
The combining circuit 19 combines the video data of the MHP application input from the Java execution unit 17 and the video data input from the AV decoder 18 and outputs combined video data.
The video / audio output circuit 20 outputs the synthesized video data input from the synthesis circuit 19 to a display device such as a display, and outputs the audio data to an audio output device such as a speaker.

FIG. 2 is a block diagram illustrating the configuration of the authentication processing unit 16 and the data flow in the digital broadcast receiver 1 according to the first embodiment. As shown in FIG. 2, the authentication processing unit 16 includes an authentication determination unit 101 and an authentication calculation processing unit 102. Upon receiving a command from the CPU 14, the authentication determination unit 101 notifies the authentication calculation processing unit 102 of information related to the MHP application received and stored in the memory 15. In response to a calculation processing command from the CPU 14, the authentication calculation processing unit 102 performs an authentication calculation process on the received MHP application, and calculates an authentication value (hash value). The authentication determination unit 101 compares the calculated authentication value with the hash value recorded in each layer of the MHP application or the hash value recorded in the memory 15 and notifies the CPU 14 of the comparison result. Further, the authentication determination unit 101 notifies the determination result to the CPU 14 according to the determination result, and deletes the data recorded in the memory 15 in some cases. Further, the authentication calculation processing unit 102 records the authentication value calculated as necessary together with the file path in the memory 15.

FIG. 3 is a diagram illustrating an example of a hierarchical structure of the MHP application received by the digital broadcast receiver 1 according to the first embodiment. The hierarchical structure shown in FIG. 3 is merely an example, and various hierarchical structures having a tree structure are included in the present invention.

In the tree structure of the MHP application shown in FIG. 3, there are two directories 3, a directory 6, a file 7, and a hash file C, which is an authentication file, in a hierarchy below the root directory. Below the directory 3, there are a file 1, a file 2, and a hash file A that is an authentication file. Similarly, files 4 and 5 and a hash file B which is an authentication file are in the lower hierarchy of the directory 6. Each hash file A, B, and C has an authentication algorithm (hash algorithm) for authentication calculation (hash calculation), for example, MD-5, SHA-1, etc., and each file and directory by the hash algorithm. A hash value (H1, H2, H3,...) That is the calculated authentication value is stored.

For example, the hash file A in the hierarchy immediately below the directory 3 includes a hash algorithm (for example, MD-5) that operates on the files 1 and 2 existing in the same hierarchy, and a file based on the hash algorithm (MD-5). 1 hash value (H1) and hash value (H2) of file 2 are stored.

The hash file B in the hierarchy immediately below the directory 6 includes a hash algorithm (for example, SHA-1) that operates on the file 4 and the file 5 existing in the same hierarchy, and the file 4 by the hash algorithm (SHA-1). A hash value (H4) and a hash value (H5) of file 5 are stored.

In the hash file C in the hierarchy immediately below the root directory, the hash value (H3) of the hash file A serving as the hash value of the directory 3 existing in the same hierarchy, and the hash value of the hash file B serving as the hash value of the directory 6 ( H6), hash value (H7) of file 7, hash file A, hash file B, and hash algorithm (MD-5) acting on file 7 are stored.

The hash value (H3) of the directory 3 is calculated by applying the hash algorithm (MD-5) stored in the hash file C to the hash file A. Similarly, the hash value ( H6) is obtained by applying the hash algorithm (MD-5) stored in the hash file C to the hash file B. Further, the hash value (H8) of the root directory is obtained by a hash algorithm (for example, MD-5, SHA-1, etc.) held by the digital broadcast receiver 1.

In the digital broadcast receiver 1 according to the first embodiment, the hash value (H8) of the root directory calculated as described above is an overall hash value (overall authentication value) obtained by performing an authentication calculation process on the entire received MHP application. ) As an index file in the memory 15. FIG. 4 is a diagram illustrating an example of an Index file in the digital broadcast receiver 1 according to the first embodiment. As shown in FIG. 4, the ID file and the entire hash value (H8) of each MHP application are stored in the Index file.

Authenticating operation when receiving a hierarchical MHP application configured as shown in FIG. 3 will be described with reference to FIG. FIG. 5 is a flowchart illustrating an authentication operation when the digital broadcast receiver 1 according to the first embodiment receives an MHP application.

In the digital broadcast receiver 1 according to the first embodiment, when the MHP application is received, the CPU 14 stores the received MHP application in the memory 15 and starts the authentication operation of the received MHP application in the authentication processing unit 16. The authentication determination unit 101 in the authentication processing unit 16 that has received a command from the CPU 14 determines whether the received MHP application is the first received MHP application (first MHP application) or not. Here, the received MHP application is the first MHP application means an MHP application that has not been loaded (received) in the past, and at least part of the contents even if it is a previously loaded (received) MHP application. This includes MHP apps that have changed. In addition, the determination that it is not the first MHP application refers to an MHP application that has been loaded (received) in the past, and the same channel is re-selected by the user's channel selection operation and the MHP application having the same content is re-received. including.

The determination operation of the authentication determination unit 101 in the digital broadcast receiver 1 according to the first embodiment is executed by detecting the identifier (application_id) of the AIT included in the transport stream (TS) (step S1). If the AIT identifier does not match any of the MHP application IDs described in the Index file shown in FIG. 4, it is determined that the AIT identifier is the first MHP application, and the AIT identifier is described in the Index file shown in FIG. If it matches any of the existing MHP application IDs, it is determined that the application is not the first MHP application. This determination result is transmitted to the authentication calculation processing unit 102, and the following authentication operation is continued. In this embodiment, whether the received MHP application is the first received MHP application or not is determined using the AIT identifier as application identification information. However, the present invention is not limited to this, and the received MHP application is not limited to this. Other application identification information that can determine whether or not is the first received MHP application may be used.

When it is determined in step S1 that the received MHP application is the first MHP application, the authentication calculation processing unit 102 sets the file structure (hierarchical structure) of the MHP application to the path (file location) of the file described in the AIT. And the path to the root directory (character string indicating the location of the root directory) (step S2).

In step S3, hash value comparison is performed in order from the lowest layer based on the recognized file structure. This hash value comparison is calculated by a hash algorithm (for example, MD-5, SHA-1, etc.) in which the hash value of each file of the hierarchy is stored in the hash file of the hierarchy, and the calculated hash value (calculation The authentication value) is compared with the hash value (stored authentication value) stored in the hash file in the hierarchy. In the hash value comparison of the hierarchy, if the hash values match, hash value comparison in another hierarchy is performed. In this way, the hash value comparison of each hierarchy is executed, and if the hash value of the hierarchy immediately below the root directory matches, it is determined that the MHP application is a valid MHP application.

The hash value comparison that is the authentication operation in step S3 will be described using the hierarchical structure shown in FIG. 3 as an example.

First, the hash values (H1, H2) of the files 1 and 2 are calculated based on the hash algorithm (MD-5) stored in the hash file A in the hierarchy immediately below the directory 3. The calculated hash values (calculated hash values: H1, H2) are compared with the hash values (stored hash values: H1, H2) stored in the hash file A. If the calculated hash values (H1, H2) and the stored hash values (H1, H2) are compared, and if they match, the hash values of the files in the hierarchy immediately below the directory 6 are compared.

In the hierarchy immediately under the directory 6, the hash values (H4, H5) of the files 4 and 5 are calculated by the hash algorithm (SHA-1) stored in the hash file B. The calculated hash value (calculated hash value: H4, H5) is compared with the hash value stored in hash file B (stored hash value: H4, H5). If the calculated hash value (H4, H5) and the stored hash value (H4, H5) are compared, if they match, the process proceeds to step S4. In step S4, it is determined whether or not the hierarchy for which the hash value comparison has been performed is a hierarchy immediately below the root directory. If the hierarchy is not immediately below the root directory, the hash value comparison of the next hierarchy is sequentially executed. To do.

Next, in the example of the hierarchical structure shown in FIG. 3, hash values of the hierarchy immediately below the root directory are compared. First, the hash value (H3) of the directory 3 is calculated by applying the hash algorithm (MD-5) stored in the hash file C to the hash file A. As a result of comparing the calculated hash value (calculated hash value: H3) with the hash value stored in the hash file C (stored hash value: H3), if they match, the hash value (H6) of the directory 6 is next. ) Is calculated by applying the hash algorithm (MD-5) stored in the hash file C to the hash file B. If the calculated hash value (calculated hash value: H6) and the hash value stored in the hash file C (stored hash value: H6) are compared, if they match, the hash value (H7) of the file 7 is next. Is calculated by the hash algorithm (MD-5) stored in the hash file C. The calculated hash value (calculated hash value: H7) is compared with the hash value (stored hash value: H7) stored in the hash file C. As a result of comparing the calculated hash value (H7) and the stored hash value (H7), if they match, the process proceeds to step S4. If it is confirmed that the upper layer is the root directory, the process proceeds to step S5, and the hash value of the root directory is obtained. (H8) is calculated by a hash algorithm (for example, MD-5, SHA-1, etc.) held by the digital broadcast receiver 1.

As described above, the hash value comparison that is the authentication operation of each layer is performed in step S3, and whether or not the layer in which the hash value comparison is performed in the next step S4 is a layer immediately below the root directory that is the highest layer. Is confirmed. In this way, the hash value comparison, which is the authentication operation described above, is executed up to the hierarchy immediately below the root directory. If the calculated hash value and the stored hash value of each layer are all matched by the authentication operation in step S3 and step S4, the received MHP application is determined to be valid. If there is a file or directory whose hash values do not match in the authentication operation (hash value comparison), the CPU 14 is notified that the MHP application is an unauthorized MHP application (step S8). The CPU 14 notified that the received MHP application is an unauthorized application prohibits display of the MHP application.
In step S5, the hash value (H8) of the highest root directory calculated by applying the hash algorithm (for example, MD-5, SHA-1, etc.) held by the digital broadcast receiver 1 to the hash file C. Is stored in the Index file of the memory 15 as a hash value (overall authentication value) of the entire MHP application (stored entire authentication value).

In step S5, the entire hash value (H8) of the MHP application is stored in the Index file in the memory 15 together with the ID of the MHP application. Thus, the Index file stores the MHP application ID of the MHP application and the entire hash value of the root directory (H8: stored overall authentication value).

In step S6, the certificate public key possessed by the digital broadcast receiver 1 is used to execute a certificate signature verification process. If there is no problem with the signature in the verification process in step S6, the hash value of the certificate is calculated in the next step S7, and the calculation result is stored in the memory 15. Further, the CPU 14 is notified that the MHP application is a valid MHP application, and the display display of the MHP application is executed.
If there is a problem in the verification process in step S6, the CPU 14 is notified of an unauthorized MHP application, and the authentication operation is terminated.

In the above authentication operation, when the user re-selects the channel, the process always returns to step S1, and the MHP application received at that time is stored in the memory 15 and the authentication processing unit 16 starts the authentication operation of the received MHP application. . Therefore, the authentication determination unit 101 of the authentication processing unit 16 that has received a command from the CPU 14 determines whether or not the received MHP application is the first received MHP application (first MHP application) (step S1). The determination operation in the authentication determination unit 101 is performed by detecting the identifier (application_id) of the AIT as described above.

If it is determined in step S1 that the MHP application corresponds to a previously loaded (received) MHP application, the process proceeds to step S9, where the entire received MHP application is calculated by authentication calculation processing. And the overall hash value (stored overall authentication value) of the past MHP application corresponding to the received MHP application stored in the memory 15 that is the storage unit. Compare. In step S9, if the received calculated total hash value of the MHP application matches the stored total hash value of the past MHP application, the above-described steps S6 and S7 are executed. That is, in step S6, the certificate signature verification process is executed. If there is no problem with the signature in the verification process, the certificate hash value is calculated in the next step S7, and the calculation result is stored in the memory 15. save. In step S7, the CPU 14 is notified that the received MHP application is a valid MHP application. Then, the display of the MHP application is performed.

In step S9, if the calculated total hash value of the MHP application and the stored total hash value of the past MHP application do not match, the contents stored in the Index file stored in the memory 15 and the past MHP application Is deleted (step S10). In step S10, after deleting the index file stored in the memory 15 and the entire stored hash value of the past MHP application, the process returns to step S2, and the file structure of the received MHP application is changed to the file described in the AIT. Recognizing from the path and the path to the root directory, the process proceeds to the steps after step S3.

For example, when the digital broadcast receiver 1 in the digital broadcast system according to the first embodiment receives the MHP application having the hierarchical structure illustrated in FIG. 3, the authentication operation as described above is executed. Therefore, in the digital broadcast receiver 1 of the first embodiment, when the digital broadcast receiver 1 first receives the MHP application, the authentication operation executes an authentication operation for performing a hash operation on all files (8 Hash calculation and hash value comparison), when a previously loaded MHP application is received, the entire hash value (calculated overall hash value) of the MHP application is calculated and stored in the memory 15. If the calculated total hash value matches the stored total hash value, it is determined that the MHP application is valid (one hash operation and hash value comparison). For this reason, in the digital broadcast receiver 1 of the first embodiment, the number of operations in the authentication operation when receiving a previously loaded MHP application is extremely reduced, and the time loss until the display of the MHP application is greatly reduced. It can be reduced.

As a result, in the digital broadcast receiver 1 according to the first embodiment, the authentication operation for verifying the reliability of the application (MHP application) based on the DVB-MHP standard in the digital broadcast receiver 1 is loaded (received) in the past. When the same MHP application as the MHP application is loaded (received), the authentication operation can be executed more reliably in a shorter time than before, and the display delay of the received MHP application is greatly improved. The user can use the receiver without discomfort.

Hereinafter, a digital broadcast receiver according to a second embodiment of the present invention will be described. The digital broadcast receiver according to the second embodiment is a receiver used in the digital broadcast system, and has substantially the same configuration as that of the digital broadcast receiver 1 according to the first embodiment. However, the digital broadcast receiver according to the second embodiment is different from the digital broadcast receiver 1 according to the first embodiment in an authentication operation when an MHP application as an application that requires an authentication process is updated. Therefore, in the description of the digital broadcast receiver of the second embodiment, the same reference numerals are given to the components having the same functions and configurations as those of the digital broadcast receiver 1 of the first embodiment, and the description of the first embodiment is applied to the description. .

The hierarchical structure shown in FIGS. 6A to 6D is a diagram showing an example of the tree structure of the MHP application received by the digital broadcast receiver of the second embodiment, and is the same as the hierarchical structure shown in FIG. 3 in the first embodiment. It is a hierarchical structure. The hierarchical structure shown in FIGS. 6A to 6D is merely an example, and various hierarchical structures are included in the present invention.

In the tree structure of the MHP application shown in FIGS. 6A to 6D, there are a directory 3, a directory 6, a file 7, and a hash file C, which is an authentication file, below the root directory. Below the directory 3 are a file 1, a file 2, and a hash file A which is an authentication file. Similarly, below the directory 6 are a file 4, a file 5, and a hash file B which is an authentication file. Each hash file A, B, and C includes an authentication algorithm (hash algorithm) for calculating a hash value of a file or directory in each layer, and an authentication value (hash value) of each file or directory based on the hash algorithm. Is stored.

For example, the hash file A in FIG. 6A stores a hash algorithm (for example, MD-5) and the hash values (H1a, H2) of the file 1 and the file 2 by the hash algorithm (MD-5). The hash file B stores the hash algorithm (SHA-1) and the hash values (H4, H5) of the files 4 and 5 by the hash algorithm (SHA-1). In the hash file C, the hash value (H3a) of the hash file A, which is the hash value of the directory 3, the hash value (H6) of the hash file B, which is the hash value of the directory 6, the hash value (H7) of the file 7, A hash algorithm (MD-5) acting on the file A, the hash file B, and the hash file 7 is stored.
As described above, the tree structure shown in FIGS. 6A to 6D has substantially the same hierarchical structure as the tree structure shown in FIG. 3, and the detailed description thereof is the same as that of the first embodiment. Incorporated and omitted here.

An authentication operation when a hierarchical MHP application configured as shown in FIGS. 6A to 6D is received will be described.
In the digital broadcast receiver according to the second embodiment, the authentication operation when the MHP application is received for the first time as in the first embodiment is substantially the same as the authentication operation described in the first embodiment.

The authentication operation in the digital broadcast receiver according to the second embodiment differs from the authentication operation according to the first embodiment in an authentication operation when a part of the received MHP application is updated (upgraded). That is, in the MHP application received by the digital broadcast receiver and displayed on the display, the authentication operation when only a part of the information in the MHP application is changed and the MHP application is updated is described above. This is different from the authentication operation in the digital broadcast receiver 1 of the first embodiment.

In the digital broadcast receiver 1 according to the first embodiment, when a part of the received MHP application is updated, the calculated total hash value for the entire MHP application in step S9 of the flowchart shown in FIG. And the stored whole hash values do not match, and the process proceeds to step S2 via step S10. In the first embodiment described above, the hash value comparison of each layer is sequentially performed from the lowest layer in the processing after step S2.

Also in the second embodiment, as in the first embodiment, for the legitimate MHP application received in the past, the entire hash value for the entire past MHP application is obtained by the authentication algorithm (hash algorithm) uniquely possessed by the digital broadcast receiver. It is calculated and stored in the Index file of the memory 15 as the entire hash value of the MHP application (H8: stored entire authentication value). Therefore, even in the digital broadcast receiver according to the second embodiment that has received the MHP application, in the first step of the authentication operation, the entire hash value of the received MHP application is calculated using a hash algorithm that the digital broadcast receiver has uniquely. The calculated total hash value (H8: calculated total authentication value) is compared with the total hash value (H8: stored total authentication value) of the past MHP application corresponding to the received MHP application. As a result of the hash value comparison, if the calculated total hash value (calculated total authentication value) matches the total hash value (stored total authentication value) of the past MHP application, the certificate possessed by the digital broadcast receiver Using the public key, the signature verification process of the certificate (Certificate) is executed. If there is no problem with the signature in this verification process, the hash value of the certificate is calculated and the calculation result is stored in the memory 15 and the CPU 14 is notified that the MHP application is a valid MHP application. To do. Then, the MHP application is displayed on the display. As described above, also in the second embodiment, the calculated total hash value of the received MHP application matches the stored total hash value of the past MHP application, as in step S9 and subsequent steps in the flowchart shown in FIG. For example, step S6 and step S7 in FIG. 5 are executed. Therefore, if there is a problem with the signature in the verification process, the CPU 14 is notified that the application is an unauthorized MHP application, and the authentication operation is terminated.

In the digital broadcast receiver according to the second embodiment, the hash value (H3) and hash value (H6) of the hash algorithm (MD-5) of the hash file C, and the hash algorithm (for example, the digital broadcast receiver has unique) , MD-5, SHA-1, etc.) are stored in the Index file of the memory 15 as the hash value (H3, H6, H8) of the MHP application in the Index file. In the Index file, the application ID of the MHP application, the entire hash value (H8), the path of the directory having the hash value (for example, directory 3, directory 6), and the hash value (for example, H6, H3) are stored.
FIG. 7 is a diagram illustrating an example of an application ID, an entire hash value (H8), a path, and hash values (H3, H6...) Stored in an Index file in the digital broadcast receiver according to the second embodiment.

Next, in the digital broadcast receiver according to the second embodiment, when the entire hash value (H8) of the received MHP application is different from the entire hash value stored in the Index file (when a part of the MHP application is updated). Will be described.
In the digital broadcast receiver of the second embodiment, when the received MHP application is updated (upgraded), naturally, the calculated overall hash value (calculated overall authentication value) and the stored overall hash value (H8: The stored total authentication value) does not match, and the authentication operation described below is executed.

In the digital broadcast receiver according to the second embodiment, in the hierarchical structure shown in FIGS. 6A to 6D, an area including the file 1, the file 2, and the hash file A is an “A area”, and the file 4, the file 5, and the hash file. An area including B will be described as “B area”, and an area including directory 3, directory 6, file 7, and hash file C will be described as “C area”.

[When only files in area "A" are updated]
The authentication operation when at least one file (for example, file 1) in the “A” area is updated in the hierarchical structure shown in FIG. 6A will be described.

In the digital broadcast receiver according to the second embodiment, when the MHP application in which only the file in the “A” area is updated is received, the CPU 14 (see FIGS. 1 and 2) stores the received MHP application in the memory 15, and The authentication processing unit 16 starts the authentication operation of the received MHP application. Upon receiving the command from the CPU 14, the authentication determination unit 101 of the authentication processing unit 16 calculates the received hash value (H8a) of the MHP application, and the calculated calculated hash value (H8a: calculated total authentication value). The entire stored hash value (H8: entire stored authentication value) of the Index file is compared. In this case, since the comparison result does not match, the hash file A in the area “A” which is the lowest layer is calculated by the hash algorithm (MD-5) stored in the hash file C, and the calculated hash value is calculated. (H3a) is acquired. The calculated hash value (H3a) is compared with the stored hash value (H3) of the Index file. The comparison result is inconsistent, and the files 1 and 2 are calculated by the hash algorithm (MD-5) stored in the hash file A to obtain the calculated hash values (H1a, H2). The obtained calculated hash values (H1a, H2) and the stored hash values (H1a, H2) stored in the hash file A are compared, and if they do not match, the CPU 14 determines that the MHP application is an unauthorized MHP application. Notice. On the other hand, if they match, the calculated hash value (H3a) of the newly calculated hash file A is stored in the Index file.

Next, the hash file B in the area “B” is calculated by the hash algorithm (MD-5) stored in the hash file C to obtain the calculated hash value (H6). The calculated hash value (H6) is compared with the stored hash value (H6) of the Index file. Since the comparison results match, the authentication operation for the area “C” is performed next.

In the area “C”, the hash value (H3a) and the hash value (H6) related to the directory 3 and the directory 6 are compared with the stored hash value (H3a) and the stored hash value (H6) stored in the hash file C. If they do not match, the CPU 14 notifies the CPU 14 that the MHP application is an unauthorized MHP application. On the contrary, if the values match, the hash value (H7) relating to the file 7 is calculated by the hash algorithm (MD-5) stored in the hash file C, and the calculated hash value (H7) is obtained. The calculated hash value (H7) is compared with the stored hash value (H7) stored in the hash file C. If the hash value comparison does not match, the CPU 14 is notified that the MHP application is an unauthorized MHP application. On the other hand, if the calculated hash value (H7) matches the stored hash value (H7), the hash operation of the hash file C is executed. The calculated hash value (H8a) obtained by applying the hash algorithm (for example, MD-5, SHA-1, etc.) inherent to the digital broadcast receiver to the hash file C is the hash value (H8a) of the root directory. And saved in the Index file.

As described above, in the authentication operation when at least one file in the “A” area is updated in the hierarchical structure shown in FIG. 6A, the calculation process is performed six times (H8a, H3a, H1a, H2, H6, H7). Thus, the authentication operation can be completed.

[When only files in "B" area are updated]
The authentication operation when at least one file (for example, file 4) in the “B” area is updated in the hierarchical structure shown in FIG. 6B will be described.

In the digital broadcast receiver according to the second embodiment, when the MHP application in which the file 4 in the “B” area is updated is received, the CPU 14 stores the received MHP application in the memory 15 and The authentication operation of the received MHP application is started. Upon receiving the command from the CPU 14, the authentication determination unit 101 of the authentication processing unit 16 calculates the entire hash value (H8b) of the received MHP application, and the calculated total hash value (H8b) and the entire storage of the Index file. The hash value (H8) is compared. In this case, since the comparison results do not match, the lowermost hash file A having the area “A” is calculated by the hash algorithm (MD-5) stored in the hash file C, and the calculated hash value is calculated. (H3) is acquired. The calculated hash value (H3) is compared with the stored hash value (H3) of the Index file. The comparison results are consistent.

Next, the hash file B in the area “B” is calculated by the hash algorithm (MD-5) stored in the hash file C to obtain the calculated hash value (H6b). The calculated hash value (H6b) is compared with the stored hash value (H6) of the Index file. Since the comparison result does not match, the files 4 and 5 are calculated by the hash algorithm (SHA-1) stored in the hash file B, and the calculated hash values (H4b, H5) are obtained. The obtained calculated hash value (H4b, H5) and the stored hash value (H4b, H5) stored in the hash file B are compared, and if they do not match, the CPU 14 determines that the MHP application is an unauthorized MHP application. Notice. On the other hand, if they match, the calculated hash value (H6b) of the newly calculated hash file B is stored in the Index file.

In the area “C”, the hash value (H3) and the hash value (H6b) related to the directory 3 and the directory 6 are compared with the stored hash value (H3) and the stored hash value (H6b) stored in the hash file C, If they do not match, the CPU 14 notifies the CPU 14 that the MHP application is an unauthorized MHP application. On the contrary, if the values match, the hash value (H7) relating to the file 7 is calculated by the hash algorithm (MD-5) stored in the hash file C, and the calculated hash value (H7) is obtained. The calculated hash value (H7) is compared with the stored hash value (H7) stored in the hash file C. If the hash value comparison does not match, the CPU 14 is notified that the MHP application is an unauthorized MHP application. On the other hand, if the calculated hash value (H7) and the stored hash value (H7) match, a hash algorithm (for example, MD-5, SHA-1, etc.) that the digital broadcast receiver has is applied to the hash file C. The hash value (H8b) acquired by the above becomes the hash value (H8b) of the root directory and is stored in the Index file.

As described above, in the authentication operation when at least one file in the “B” area is updated in the hierarchical structure shown in FIG. 6B, the calculation processing is performed six times (H8b, H3, H6b, H4b, H5, H7). Thus, the authentication operation can be completed.

[When only files in "C" area are updated]
The authentication operation when at least one file (file 7) in the “C” area is updated in the hierarchical structure shown in FIG. 6C will be described.

In the digital broadcast receiver according to the second embodiment, when the MHP application in which only the file 7 in the “C” area is updated is received, the CPU 14 stores the received MHP application in the memory 15 and The authentication operation of the received MHP application is started. Upon receiving the command from the CPU 14, the authentication determination unit 101 of the authentication processing unit 16 calculates the entire hash value (H8c) of the received MHP application, and stores the calculated total hash value (H8c) and the entire index file storage. The hash value (H8) is compared. In this case, since the comparison results do not match, the lowermost hash file A having the area “A” is calculated by the hash algorithm (MD-5) stored in the hash file C, and the calculated hash value is calculated. (H3) is acquired. The calculated hash value (H3) is compared with the stored hash value (H3) of the Index file. The comparison results are consistent.

Next, the hash file B in the area “B” is calculated by the hash algorithm (MD-5) stored in the hash file C to obtain the calculated hash value (H6). The calculated hash value (H6) is compared with the stored hash value (H6) of the Index file. The comparison results are consistent.

Next, in the updated area “C”, the hash value (H3) and the hash value (H6) regarding the directory 3 and the directory 6, and the stored hash value (H3) and the stored hash value ( H6) is compared, and if they do not match, the CPU 14 is notified that the MHP application is an unauthorized MHP application. On the other hand, if they match, the file 7 is calculated by the hash algorithm (MD-5) stored in the hash file C to obtain the calculated hash value (H7c). The calculated hash value (H7c) is compared with the stored hash value (H7c) stored in the hash file C. If the hash value comparison does not match, the CPU 14 is notified that the MHP application is an unauthorized MHP application. On the other hand, if the calculated hash value (H7c) and the stored hash value (H7c) match, a hash algorithm (for example, MD-5, SHA-1 or the like) that the digital broadcast receiver has is applied to the hash file C. The hash value (H8c) acquired by the above becomes the hash value (H8c) of the root directory and is stored in the Index file.

As described above, in the authentication operation when at least one file in the “C” area is updated in the hierarchical structure shown in FIG. 6C, the authentication operation is performed by four times (H8c, H3, H6, H7c) of arithmetic processing. Can be completed.

[When only files in "A" area and "C" area are updated]
In the hierarchical structure shown in FIG. 6D, an authentication operation when files (for example, file 1 and file 7) in the “A” area and the “C” area are updated will be described.

In the digital broadcast receiver according to the second embodiment, when the MHP application in which the files in the “A” area and the “C” area are updated is received, the CPU 14 stores the received MHP application in the memory 15 and the authentication processing unit 16. In response, the authentication operation of the received MHP application is started. Upon receiving the command from the CPU 14, the authentication determination unit 101 of the authentication processing unit 16 calculates the entire hash value (H8d) of the received MHP application, and the calculated total hash value (H8d) and the entire storage of the Index file. The hash value (H8) is compared. In this case, since the comparison results do not match, the lowermost hash file A having the area “A” is calculated by the hash algorithm (MD-5) stored in the hash file C, and the calculated hash value is calculated. (H3a) is acquired. The calculated hash value (H3a) is compared with the stored hash value (H3). Since the comparison result is inconsistent, the files 1 and 2 are calculated by the hash algorithm (MD-5) stored in the hash file A, and the calculated hash values (H1a, H2) are obtained. The obtained calculated hash value (H1a, H2) and the stored hash value (H1a, H2) are compared, and if they do not match, the CPU 14 is notified that the MHP application is an unauthorized MHP application. On the other hand, if they match, the calculated hash value (H3a) of the newly calculated hash file A is stored in the Index file.

Next, the hash file B in the area “B” is calculated by the hash algorithm (MD-5) stored in the hash file C to obtain the calculated hash value (H6). The calculated hash value (H6) and the stored hash value (H6) are compared. Since the comparison results match, the authentication operation for the area “C” is performed next.

Next, a hash operation is performed on the updated area “C”. The hash value (H3a) and hash value (H6) related to the directory 3 and directory 6 are compared with the stored hash value (H3a) and stored hash value (H6) stored in the hash file C. The CPU 14 notifies the CPU 14 that the MHP application is an unauthorized MHP application. On the contrary, if the values match, the hash value related to the file 7 is calculated by the hash algorithm (MD-5) stored in the hash file C to obtain the calculated hash value (H7c). The calculated hash value (H7c) is compared with the stored hash value (H7c) stored in the hash file C. If the hash value comparison does not match, the CPU 14 is notified that the MHP application is an unauthorized MHP application. On the other hand, if the calculated hash value (H7c) and the stored hash value (H7c) match, a hash algorithm (for example, MD-5, SHA-1 or the like) that the digital broadcast receiver has is applied to the hash file C. The hash value (H8d) acquired by the above becomes the hash value (H8d) of the root directory and is stored in the Index file.

As described above, in the hierarchical structure shown in FIG. 6D, the authentication operation when the files in the “A” area and the “C” area are updated is performed six times (H8d, H3a, H1a, H2, H6, H7c). The authentication operation can be completed by the arithmetic processing.

As described above, in the authentication operation in the digital broadcast receiver according to the second embodiment, the hash values of hash files are compared for each region. For this reason, when only a specific area is updated, a hash operation is performed on the hash file in the specific area, and in a non-updated area, authentication is performed only with the hash operation of the hash file. . Therefore, in the authentication operation in the digital broadcast receiver according to the second embodiment, it is not necessary to perform hash operations on files and directories in all layers, and the number of hash operations and the number of hash value comparisons can be greatly reduced. .

As a result, in the digital broadcast receiver according to the second embodiment, the authentication operation for verifying the credibility of the application (MHP application) compliant with the DVB-MHP standard in the digital broadcast receiver is changed to a partially updated MHP application. When received, it can be executed reliably in a short time compared to the conventional case, the delay of the MHP application display is greatly improved, and the user can use the digital broadcast receiver without discomfort. Become.

In the first and second embodiments, a reception data authentication method and a digital broadcast receiver that perform authentication processing for verifying the reliability of an application compliant with the DVB-MHP standard in a shorter time than before are described. However, the present invention is not limited to the DVB-MHP standard, and the received data authentication method and digital broadcast receiver of the present invention can be used for applications that require authentication processing similar to the DVB-MHP standard, for example, the standard for cable television in North America. The present invention can also be applied to an application conforming to the standard OCAP (OpenCable Application Platform) standard.

The present invention provides a highly useful digital broadcast receiver capable of performing an authentication operation for verifying the reliability of an application in a short time when an application conforming to the DVB-MHP standard is received in the digital broadcast system. can do.

1 Digital Broadcasting Receiver 2 Remote Control 11 Antenna 12 Tuner 13 Transport Decoder (TD)
14 CPU
DESCRIPTION OF SYMBOLS 15 Memory 16 Authentication process part 17 Java execution part 18 AV decoder 19 Composition circuit 20 Video | audio output circuit 21 Remote control receiver 101 Authentication determination part 102 Authentication calculation process part

Claims (10)

1. A receiving step for receiving an application requiring authentication processing (hereinafter, abbreviated as an authentication application);
   A determination step of determining whether the received authentication application is an application received for the first time based on application identification information;
   In the determination step, when it is determined that the received authentication application is an application received for the first time, a hierarchy authentication calculation step for executing an authentication calculation process for each layer of the received authentication application,
   If the calculated authentication value of each layer calculated in the hierarchical authentication calculation step is the same as the stored authentication value stored in the authentication file of the authentication application, the control unit determines that the received authentication application is a valid application And storing the authentication calculation result for the received authentication application as a whole storage authentication value in the storage unit,
   In the determination step, when it is determined that the received authentication application is not an application received for the first time, an overall authentication calculation step for executing an authentication calculation process for the entire received authentication application,
   A comparison step of comparing the calculated overall authentication value calculated by the authentication calculation process for the entire received authentication application with the stored overall authentication value for the entire past authentication application corresponding to the received authentication application;
   A notification step of notifying the control unit that the received authentication application is a valid application when the calculated total authentication value and the stored total authentication value match;
   A received data authentication method.
2. When the calculated total authentication value and the stored total authentication value do not match, the stored total authentication value for the entire past authentication application corresponding to the received authentication application stored in the storage unit is deleted, and the hierarchy An authentication calculation step and a deletion step to move to the storage step;
   The received data authentication method according to claim 1, further comprising:
3. The received data authentication method according to claim 1, wherein a calculated overall authentication value for the received authentication application as a whole is stored in the storage unit together with an identification number of the received authentication application.
4. The calculated overall authentication value for the received authentication application as a whole is calculated by an authentication calculation process using a unique authentication algorithm of the digital broadcast receiver, and in the comparison step, the calculated overall authentication value is The received data authentication method according to claim 1, wherein the entire past authentication application corresponding to the received authentication application is compared with a stored whole authentication value that has been subjected to authentication calculation processing by the unique authentication algorithm.
5. In the comparison step, when the calculated overall authentication value for the received authentication application as a whole does not match the stored overall authentication value for the entire past authentication application corresponding to the received authentication application, sequentially from the lowest layer area The area authentication value comparison is performed by comparing the area calculation authentication value calculated by the authentication calculation process for each authentication file belonging to each hierarchical area and the area storage authentication value of the authentication file belonging to the hierarchical area, and the area authentication value The received data authentication method according to claim 4, wherein when the values match in the comparison, the hierarchical area of the received authentication application is determined not to be changed from the hierarchical area of the past authentication application.
6. 5. The received data authentication method according to claim 4, wherein the calculated overall authentication value and the authentication value of the authentication file for the entire received authentication application are stored in the storage unit together with the identification number of the received authentication application.
7. In a digital broadcast receiver that receives an application requiring authentication processing (hereinafter abbreviated as an authentication application)
   A receiving unit that receives the authentication application, an authentication processing unit that performs an authentication calculation process on the received authentication application, and
   A storage unit for storing the result of the authentication calculation process;
   A control unit that controls the entire digital broadcast receiver,
   In the authentication calculation process in the authentication processing unit, an authentication value for the entire authentication application that has been authenticated in the past is calculated and stored in the storage unit as a stored overall authentication value. Configured to notify the control unit that the received authentication application is a legitimate application when the calculated total authentication value for the entire authentication application matches the stored total authentication value stored in the storage unit. Digital broadcast receiver.
8. The authentication processing unit includes an authentication determination unit and an authentication calculation processing unit,
   The authentication determination unit receives an instruction from the control unit and notifies the authentication calculation processing unit of information related to the received authentication application,
   The authentication calculation processing unit executes an authentication calculation process for the received authentication application as a whole, calculates a calculated overall authentication value,
   In the authentication determination unit, the calculated overall authentication value is compared with the stored overall authentication value stored in the storage unit for the entire past authentication application corresponding to the received authentication application, 8. The control unit according to claim 7, configured to notify the control unit that the received authentication application is a valid application when a comparison result between the calculated total authentication value and the stored total authentication value matches. Digital broadcast receiver.
9. In the authentication processing unit, when the calculated total authentication value for the received authentication application as a whole does not match the stored total authentication value for the entire past authentication application corresponding to the received authentication application, sequentially from the lowest layer area The region authentication value comparison is performed by comparing the region calculation authentication value calculated by the authentication calculation process for each authentication file belonging to each hierarchical region with the region storage authentication value of the authentication file belonging to the hierarchical region, and The digital broadcast receiver according to claim 7, wherein when the values match in the value comparison, the received authentication application hierarchy area is determined not to be changed from the past authentication application hierarchy area.
10. The digital broadcast receiver according to claim 7, wherein the calculated total authentication value and the authentication value of the authentication file for the entire received authentication application are stored in the storage unit together with the identification number of the received authentication application.

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