JPH04320181A - Electronic device - Google Patents

Abstract

PURPOSE:To prevent interception of a toll program due to rewrite of contract information by providing a daily data area to a storage device. CONSTITUTION:A transmission data from a CATV station 1 is decoded by a controller 9 according to application of contract from a subscriber and the result is stored in a storage device 6. When the subscriber uses a key switch 7 or the like to select a channel, the controller 9 operates a descrambler 5 based on a data of the storage device 6 to receive a designated channel. The CATV station revises a daily data every day together with contract information or the like and sends the result thereby rewriting the daily data area provided to the storage device 6. Then the controller 9 checks the daily data area and when the data differs from a designated data, it is discriminated to be interception and the reception by the descrambler is disabled. Thus, the interception of the toll program is prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electronic equipment such as cable television terminals having a function of enabling or disabling the reception of pay programs by remote control from a CATV center.

0002

2. Description of the Related Art Conventionally, this type of cable television terminal has been constructed as shown below. That is, C
In the ATV system, pay programs are scrambled, and a descrambler is operated to enable reception of only the channels subscribed to by the subscriber. Information on channels subscribed to by subscribers is stored as data in a designated area of a storage device such as E2PROM or RAM installed in a cable TV terminal, and the control device operates based on the data in this storage device. The descrambler was running.

0003

[Problems to be Solved by the Invention] In the configuration of such a conventional cable television terminal, the location of the contract channel data stored in the storage device is fixed, which causes the following problems. That is, there is a problem in that an eavesdropper can easily rewrite all paid programs into receivable data using a memory programmer using an IC clip or the like, and as a result, the program can be eavesdropped.

An object of the present invention is to prevent data in a storage device from being intercepted even if it is illegally rewritten.

[0005]

[Means for Solving the Problems] In order to achieve the above object, an electronic device of the present invention is configured such that a storage device is provided with a daily data area in which daily data is replaced by external data.

[0006]

[Operation] With this configuration, the data in the storage device changes daily, so even if an eavesdropper were to rewrite the data in the storage device, it would be impossible to change even the data that changes daily. Therefore, wiretapping can be reliably prevented.

[0007]

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

FIG. 2 is a block diagram of a cable television terminal according to an embodiment of the present invention, and FIG. 1 is a data map diagram showing a data area of a storage device provided in the cable television terminal.

In FIG. 2, 1 is a CATV station, and 2 is a CATV cable for transmitting cable TV signals and data. 3 is an up-down converter that selects one station from among the cable television signals transmitted from CATV station 1 and converts the signal into a specific television signal channel; 4 is channel contract data transmitted from CATV station 1; 5 is a descrambler for decoding the scrambled cable television signal. Further, 6 is a storage device in which data such as channel contract information and descrambler control contract information is stored, 7 is a key switch, and 8 is a remote control receiver. And these 3 to 8
The elements are each connected to a control device 9. Also,
Reference numeral 10 denotes a power supply section, which supplies necessary power. Here, 11 is a remote control transmitter that transmits a signal to the remote control receiver 8.

Next, the operation of the cable television terminal will be explained. When a subscriber applies to the CATV station 1 for the channel he/she wants to subscribe to, data is transmitted from the CATV station 1, the data is received by the data receiver 4, and the data is sent to the control device 9.
decodes the data and stores it in the storage device 6. When a subscriber selects a channel using the key switch 7 or the remote control transmitter 11, the control device 9 operates as a descrambler that enables or disables reception of the specified channel based on the data in the storage device 6. Operate 5.

FIG. 1 is a data map diagram showing a data area of a storage device 6 provided in a cable television terminal, and has a structure of n addresses×m bits. The aforementioned channel contract information, descrambler control information, and the like are stored such that, for example, 1 indicates a contract and 0 indicates a non-contract. A daily data area 12 as a check bit is provided at each address. The CATV station 1 changes and transmits daily data 12 every day in the same way as it transmits channel contract information and descrambler contract information. The aforementioned control device 7 rewrites the daily data area 12 of the storage device 6 based on the received data. Therefore, the same data does not exist at each address every day.

Furthermore, the control device 9 periodically checks the daily data area 12 and updates the daily data area 1.
2 is different from the specified data, it is determined that wiretapping has occurred, and wiretapping can be prevented by making all channels of the cable TV terminal unreceivable.

[0013] Furthermore, it goes without saying that if the arrangement of the daily data area 12 is moved periodically, the eavesdropping prevention function will be further improved.

As described above, according to the cable television terminal of this embodiment, even if the data in the storage device 6 is rewritten externally using a memory programmer using an IC clip or the like, pay programs cannot be intercepted. There isn't.

[0015]

[Effects of the Invention] As described above, according to the present invention, the data in the storage device is changed every day, so even if an eavesdropper were to rewrite the data in the storage device, it would not be possible to change the data, including the data that changes daily. It's impossible. Therefore, wiretapping can be reliably prevented.

[Brief explanation of drawings]

FIG. 1 is a data map diagram showing a data area of a storage device provided in a cable television terminal according to an embodiment of the present invention.

FIG. 2 is a block diagram of a cable television terminal according to an embodiment of the present invention.

[Explanation of symbols]

1 CATV station 2 CATV cable 3 Up-down converter 4 Data receiver 5 Discrambler 6. Storage device 9 Control device 12 Daily data area

Claims (3)

[Claims] 1. A storage device, a control device connected to the storage device, a data receiver connected to the control device to receive external data, and a descrambler operating based on the external data, the An electronic device that has a storage device with a daily data area where daily data is changed depending on signals input to external data. 2. The electronic device according to claim 1, wherein if the daily data differs from predetermined data, all channels are made unreceivable. 3. The electronic device according to claim 1, wherein the storage location of daily data is periodically changed.