JPH07131373A - Data distribution system - Google Patents

Abstract

(57) [Abstract] [Purpose] To solve the inconvenience of not being able to hold a newly transmitted work key due to a lack of storage capacity. [Structure] An end signal is provided by a transmission system 101 in accordance with the end of a program, and the end signal is taken into a receiver 109 through a tuner 103, and the end signal is received by the reception processing circuit 1.
Passed to 04. The reception processing circuit 104 recognizes the end signal, passes it to the control unit 107, and deletes the work key from the storage unit 108. The work key, which is the encryption key for each program, is deleted at the same time as the program ends, and even if the programs are sent continuously in a short time, there will be no shortage of storage capacity, and newly sent programs It becomes possible to retain the work key of.

Description

Detailed Description of the Invention

[0001]

[Industrial field of use] In recent years, a data distribution system has been developed which provides various services by multiplexing data into an independent data part of a video distribution system using satellites and a digital channel which is an empty area of voice. There is. The present invention relates to this data distribution system.

[0002]

2. Description of the Related Art In recent years, image distribution systems using satellites have already been developed. It is possible to provide a plurality of services by multiplexing the data in the data channel area including the independent data part of the video distribution system and the vacant portion of the signal generated according to the usage form of the sound. In this data distribution system, in order to receive the scrambled service,
The receiver must already have the qualification to receive. For that purpose, it is necessary to have the encryption key for descrambling the contract receiver at the time of signing the reception contract, and before the service is started, the encryption key is sent to the specific receiver via the radio wave. Must be sent to. The present invention particularly relates to a work key which is an encryption key for each program for encrypting and decrypting a key for scrambling actual program content. The encryption key was not always sent from the sender side, and it was necessary to hold the work key.

The processing of the work key in the conventional receiver will be described below. FIG. 6 shows the structure of a conventional receiver. In FIG. 6, 601 is a transmission system, 602 is a satellite, 603 is a CS tuner, 604 is a reception processing circuit, and 6
Reference numeral 05 is a ROM, 606 is a terminal interface unit, 607
Is a control unit, 608 is a storage unit, 609 is a receiver, and 610 is a service terminal.

In the receiver of the data distribution system configured as described above, the operation of the work key receiving process will be described below with reference to FIG. First, the work key is CS
Receiver 60 from tuner 603 as authorization information
Passed to 9. The authorization information received from the CS tuner 603 was analyzed by the reception processing circuit 604, passed to the control unit 607, and held in the storage unit 608. However, the held work key is deleted when the expiration date in the same authorization information expires. FIG. 5 shows a state of being held in the storage unit.

[0005]

However, in the above-mentioned conventional configuration, the work key is provided with an expiration date, and the receiver deletes the work key when the expiration date has passed. If it is sent continuously, it means that as many work keys as sent are held in the receiver's storage section, so the receiver's storage section has a limit of capacity, and it will exceed it. However, there is a problem that the program cannot be received because the newly received work key cannot be held.

An object of the present invention is to solve the above-mentioned conventional problems, and an object thereof is to provide a data distribution system which makes it possible to prevent a storage unit from having insufficient capacity due to holding a work key in a receiver.

[0007]

In order to achieve this object, a transmission system for transmitting an end signal indicating the end of a program, a storage unit for holding a work key, and a reception process for analyzing a signal received from a CS tuner R to instruct the circuit and reception processing circuit
It is configured to have a receiver including an OM, a control unit, and a terminal interface unit.

[0008]

With this configuration, when the program ends, the end signal indicating the end of the program is transmitted from the transmission system, and the end signal is passed from the CS tuner to the reception processing circuit of the data decoder via the satellite line. The reception processing circuit recognizes the end signal, passes it to the control unit, and deletes the work key from the storage unit. As a result, the work key, which is the encryption key for each program, is deleted at the same time as the program ends, and even if the program is sent continuously in a short time, the storage capacity will not be insufficient, and it will be newly sent. The problem that the work key of the received program cannot be held and the program cannot be received is solved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 101 is a transmission system, 102 is a satellite, 103 is a CS tuner, 104 is a reception processing circuit,
105 is a ROM, 106 is a terminal interface unit, 10
7 is a control unit, 108 is a storage unit, 109 is a receiver, and 110 is a service terminal.

The operation of the data distribution system configured as described above will be described with reference to FIG. First,
When the transmission of the program ends from the transmission system 101, an end signal indicating the end of the program is transmitted. The end signal is received by the receiver 109 from the CS tuner 103 via the satellite 102 and passed to the reception processing circuit 104. Reception processing circuit 10
4 is recognized as the end signal, and the control unit 107 causes the storage unit 10
8 work keys are deleted. FIG. 2 shows the usage status of the area of the conventional storage unit and the usage status of the storage unit of the present invention. (A)
Is the state of the conventional storage unit, and work key 1 to work key 7
Is waiting for the deadline, and the work keys 8 to 10 are receiving the program, and are still held in the storage unit.
In the state of the storage unit of the present invention in (b), the work key 1 to work key 7 have already been programmed, and the work key has been deleted. The work key 8 to the work key 10 are receiving the program, and are in a state of being held in the storage unit. Comparing the states of the storage section in (a) and (b), it can be seen that when a plurality of programs are transmitted at the same time, the state of the conventional storage section in (a) shows that the program has ended. Nevertheless, the work key remains stored in the storage unit and is not deleted until the expiration date. On the other hand, looking at the state of the storage unit of the present invention in (b), only the area for the work key of the program being received is used.

As is apparent from FIG. 2, the data distribution system according to the present embodiment efficiently uses the storage unit of the receiver, prevents the lack of capacity, and solves the problem that the program cannot be received. Excellent effect can be obtained.

The CS tuner 103 and the receiver 109 are integrated from the configuration of the embodiment, and the same effect can be obtained even with the configuration as shown in FIG. 3. Further, the service terminal 110 and the receiver 109 are integrated. Needless to say, the same effect can be obtained even with the configuration shown in FIG.

[0014]

As described above, the present invention is provided with a transmission system for transmitting an end signal indicating the end of a program, and when the end signal is received by the receiver, the work key is erased from the storage unit, so that the storage unit Therefore, it is possible to realize an excellent data distribution system that can prevent the work key of a newly transmitted program from being held and the program from becoming unreceivable due to lack of capacity.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a data distribution system according to an embodiment of the present invention.

2A is a state diagram of a storage unit of a receiver that holds a conventional work key; FIG. 2B is a state diagram of a storage unit of a receiver that holds a work key according to the present invention.

FIG. 3 is a configuration diagram of a data distribution system according to an embodiment of the present invention.

FIG. 4 is a configuration diagram of a data distribution system according to an embodiment of the present invention.

FIG. 5 is a state diagram of a storage unit of a receiver that holds a conventional work key.

FIG. 6 is a block diagram of a conventional data distribution system.

[Explanation of symbols]

101, 301, 401, 601 Transmission system 102, 302, 402, 602 Satellite 103, 303, 403, 603 CS tuner 104, 304, 404, 604 Reception processing circuit 105, 305, 405, 605 ROM 106, 306, 406, 606 Terminal interface section 107, 307, 407, 607 Control section 108, 308, 408, 608 Storage section 109, 309, 409, 609 Receiver 110, 310, 410, 610 Service terminal

Claims (1)

[Claims] 1. A transmission system characterized by providing an end signal indicating the end of a program and transmitting the end signal simultaneously with the end of the program using a data channel of satellite broadcasting, and receiving the end signal from a satellite. Then, a tuner for transmitting to the receiver, a reception processing circuit that receives the end signal from the tuner and recognizes it as an end signal, a control unit that receives and controls the end signal from the reception processing circuit, and an encryption key. A receiver, comprising: a receiver having a storage unit for holding the storage unit; and a service terminal, wherein when the reception processing circuit receives the end signal, the encryption key stored in the storage unit is deleted. A data distribution system having.