Abstract: Unlike the technology for a program downloaded through conventional broadcast waves, in the case of downloading a program via a network, there is a possibility that such program will be activated without noticing that the program is tampered with. For this reason, when a program is downloaded via a network, a file hierarchy for the program located on a server is constructed in a local area of a terminal. Subsequently, the authentication of the program is performed with respect to the file hierarchy constructed in the local area, and the credibility of the program is guaranteed.

Abstract: According to a conventional technique, in the case where a program is stored into a non-volatile memory once and then activated, authentication of the program is performed immediately before such activation. However, calculations such as decryption of encrypted values are required before the activation of the program starts, which causes the problem that responsiveness is decreased in proportion to the time required for calculations. In order to solve this problem, authentication of a program is performed immediately before such program is stored, so that no authentication is performed or only a part of the authentication is performed to verify the validity of certificates at program activation time.

Abstract: Conventionally, when the version of a program has been upgraded, the whole of a currently stored program needs to be deleted to be replaced by a new program, and authentication needs to be performed again on such new program when it is activated. However, since the whole of the program is required to be stored and authenticated even when only a part of such program has changed, it consumes time and leads to the decrease in responsiveness. In order to solve this problem, the present invention extracts a difference between a new program and a currently stored old program, when such new program is to be stored, and the new program is to be stored after authentication is performed only on such difference.

Abstract: Unlike the technology for a program downloaded through conventional broadcast waves, in the case of downloading a program via a network, there is a possibility that such program will be activated without noticing that the program is tampered with. For this reason, when a program is downloaded via a network, a file hierarchy for the program located on a server is constructed in a local area of a terminal. Subsequently, the authentication of the program is performed with respect to the file hierarchy constructed in the local area, and the credibility of the program is guaranteed.

Abstract: According to a conventional technique, in the case where a program is stored into a non-volatile memory once and then activated, authentication of the program is performed immediately before such activation. However, calculations such as decryption of encrypted values are required before the activation of the program starts, which causes the problem that responsiveness is decreased in proportion to the time required for calculations. In order to solve this problem, authentication of a program is performed immediately before such program is stored, so that no authentication is performed or only a part of the authentication is performed to verify the validity of certificates at program activation time.

Abstract: Unlike the technology for a program downloaded through conventional broadcast waves, in the case of downloading a program via a network, there is a possibility that such program will be activated without noticing that the program is tampered with. For this reason, when a program is downloaded via a network, a file hierarchy for the program located on a server is constructed in a local area of a terminal. Subsequently, the authentication of the program is performed with respect to the file hierarchy constructed in the local area, and the credibility of the program is guaranteed.

Abstract: According to a conventional technique, in the case where a program is stored into a non-volatile memory once and then activated, authentication of the program is performed immediately before such activation. However, calculations such as decryption of encrypted values are required before the activation of the program starts, which causes the problem that responsiveness is decreased in proportion to the time required for calculations. In order to solve this problem, authentication of a program is performed immediately before such program is stored, so that no authentication is performed or only a part of the authentication is performed to verify the validity of certificates at program activation time.

Abstract: According to a conventional technique, in the case where a program is stored into a non-volatile memory once and then activated, authentication of the program is performed immediately before such activation. However, calculations such as decryption of encrypted values are required before the activation of the program starts, which causes the problem that responsiveness is decreased in proportion to the time required for calculations. In order to solve this problem, authentication of a program is performed immediately before such program is stored, so that no authentication is performed or only a part of the authentication is performed to verify the validity of certificates at program activation time.

Abstract: A broadcast system BS includes a broadcast apparatus 1 and a reception apparatus 2. The broadcast apparatus 1 first receives and stores therein a proxy request PR including at least an identifier assigned to the reception apparatus 2 and a command to be transmitted to the reception apparatus 2. Moreover, the broadcast apparatus 1 extracts the set of the identifier of the reception apparatus 2 and the command for the reception apparatus 2 from the proxy request PR stored therein, and assembles a command packet from the set of the identifier and the command. Then, the broadcast apparatus 1 generates a stream in which the assembled command packet is multiplexed, and sends it out to a broadcast channel. The reception apparatus 2 separates the command packet from the stream sent out to the broadcast channel, and restores the set of the identifier and the command of the reception apparatus 2.

Abstract: A broadcast system BS includes a broadcast apparatus 1 and a reception apparatus 2. The broadcast apparatus 1 first receives and stores therein a proxy request PR including at least an identifier assigned to the reception apparatus 2 and a command to be transmitted to the reception apparatus 2. Moreover, the broadcast apparatus 1 extracts the set of the identifier of the reception apparatus 2 and the command for the reception apparatus 2 from the proxy request PR stored therein, and assembles a command packet from the set of the identifier and the command. Then, the broadcast apparatus 1 generates a stream in which the assembled command packet is multiplexed, and sends it out to a broadcast channel. The reception apparatus 2 separates the command packet from the stream sent out to the broadcast channel, and restores the set of the identifier and the command of the reception apparatus 2.

Abstract: A broadcast system BS includes a broadcast apparatus 1 and a reception apparatus 2. The broadcast apparatus 1 first receives and stores therein a proxy request PR including at least an identifier assigned to the reception apparatus 2 and a command to be transmitted to the reception apparatus 2. Moreover, the broadcast apparatus 1 extracts the set of the identifier of the reception apparatus 2 and the command for the reception apparatus 2 from the proxy request PR stored therein, and assembles a command packet from the set of the identifier and the command. Then, the broadcast apparatus 1 generates a stream in which the assembled command packet is multiplexed, and sends it out to a broadcast channel. The reception apparatus 2 separates the command packet from the stream sent out to the broadcast channel, and restores the set of the identifier and the command of the reception apparatus 2.

Abstract: A broadcast system BS includes a broadcast apparatus 1 and a reception apparatus 2. The broadcast apparatus 1 first receives and stores therein a proxy request PR including at least an identifier assigned to the reception apparatus 2 and a command to be transmitted to the reception apparatus 2. Moreover, the broadcast apparatus 1 extracts the set of the identifier of the reception apparatus 2 and the command for the reception apparatus 2 from the proxy request PR stored therein, and assembles a command packet from the set of the identifier and the command. Then, the broadcast apparatus 1 generates a stream in which the assembled command packet is multiplexed, and sends it out to a broadcast channel. The reception apparatus 2 separates the command packet from the stream sent out to the broadcast channel, and restores the set of the identifier and the command of the reception apparatus 2.

Abstract: Unlike the technology for a program downloaded through conventional broadcast waves, in the case of downloading a program via a network, there is a possibility that such program will be activated without noticing that the program is tampered with. For this reason, when a program is downloaded via a network, a file hierarchy for the program located on a server is constructed in a local area of a terminal. Subsequently, the authentication of the program is performed with respect to the file hierarchy constructed in the local area, and the credibility of the program is guaranteed.

Abstract: According to a conventional technique, in the case where a program is stored into a non-volatile memory once and then activated, authentication of the program is performed immediately before such activation. However, calculations such as decryption of encrypted values are required before the activation of the program starts, which causes the problem that responsiveness is decreased in proportion to the time required for calculations. In order to solve this problem, authentication of a program is performed immediately before such program is stored, so that no authentication is performed or only a part of the authentication is performed to verify the validity of certificates at program activation time.

Abstract: Conventionally, when the version of a program has been upgraded, the whole of a currently stored program needs to be deleted to be replaced by a new program, and authentication needs to be performed again on such new program when it is activated. However, since the whole of the program is required to be stored and authenticated even when only a part of such program has changed, it consumes time and leads to the decrease in responsiveness. In order to solve this problem, the present invention extracts a difference between a new program and a currently stored old program, when such new program is to be stored, and the new program is to be stored after authentication is performed only on such difference.

Abstract: A broadcast system BS includes a broadcast apparatus 1 and a reception apparatus 2. The broadcast apparatus 1 first receives and stores therein a proxy request PR including at least an identifier assigned to the reception apparatus 2 and a command to be transmitted to the reception apparatus 2. Moreover, the broadcast apparatus 1 extracts the set of the identifier of the reception apparatus 2 and the command for the reception apparatus 2 from the proxy request PR stored therein, and assembles a command packet from the set of the identifier and the command. Then, the broadcast apparatus 1 generates a stream in which the assembled command packet is multiplexed, and sends it out to a broadcast channel. The reception apparatus 2 separates the command packet from the stream sent out to the broadcast channel, and restores the set of the identifier and the command of the reception apparatus 2.