JPH02186852A - Secret device - Google Patents

Abstract

PURPOSE:To obtain a secret device hard to decode by providing a storage means to store encoded data in which a scramble signal having the extension of spectrum less than that of an information signal to be transmitted at a transmitter side and a receiver side, respectively. CONSTITUTION:The information signals (a) transmitted from the transmitters 1-5 are transmitted after being added on or subtracted from the decoding signal of the encoded data (d) of the scramble signal (e) in the storage means 2. And at the receivers 6-10 side, addition or subtraction between the demodulation signal (g) of a reception signal (f) and the demodulation signal (j) of the encoded data (i) of the scramble signal in the storage means 8 is performed, then, the separation of the scramble signal is performed, and the information signal with the same content as that of a transmitted information signal (a) can be obtained. In such a way, the secret device with high secrecy can be obtained.

Description

[Detailed description of the invention] [Industrial application field] TECHNICAL FIELD This invention relates to a concealed device for communication.

[Conventional technology]

Figure 4 shows, for example, the paper "Mystic Analog Speech Scrambler" (Philips Telecommunications Newsletter, Vol. 41, No. 1, April 1983).
ipa Telecommunication Rev
iew, Vol, 41, No, 1 rA
prill 1983, MISTICanalog
5peech 5crarnbler) is a block circuit diagram of a conventional concealment device shown in FIG.
5 is a spectrum inverter that inverts the spectrum of the input information signal (a), 5 is a transmitter that transmits the inverted signal (f) to the spectrum inverter 11, and 6 is a transmitter that transmits the transmitted signal (f). The receiving section 12 that receives the signal is a spectrum inverting section that inverts the spectrum of the demodulated signal (b) received by the receiving section 6.

Next, the operation will be explained. Input information signal (a)
The spectrum of is inverted by the spectrum inverter 11, and the inverted signal (f) is transmitted from the transmitter 5. In this case, FIG. 5(1) K shows the spectrum of the input information signal (a), and FIG. 5(2) shows the inverted signal (f).

The transmitted signal (f) is received by the receiver 6 and demodulated to become a signal (g), and the spectrum of this signal (g) is inverted by the spectrum inverter 12 to form the information signal. Information signal with the same spectrum as (a) (
b) is obtained.

[Problem to be solved by the invention]

Since the conventional concealment device is configured as described above, a third party can reproduce the receiving section 6 and the spectrum inverting section 12,
There was a problem that the contents of the communication could be easily deciphered, and therefore the confidentiality of the communication could not be kept.

This invention was made to solve the above-mentioned problems, and aims to provide a secret device that cannot be easily decrypted.

[Means for Solving the Problem] The concealment device according to the present invention stores the encoded data of a scrambled signal in a storage means that stores in advance encoded data of a scrambled signal having a spectrum spread equal to or less than that of the information signal to be transmitted. a transmitter that transmits a signal obtained by adding or subtracting a decoded signal of the encoded data and the information signal; a signal that receives the signal transmitted from the transmitter and demodulates the received signal; and a signal that is stored in advance in a storage means. the received signal and the decoded signal of the encoded data of the scrambled signal to separate the information signal in the received signal and the scrambled signal, and output the same information signal as the transmitted information signal; It is equipped with a machine.

[Effect]

The information signal transmitted from the transmitter in this invention is transmitted after being added to or subtracted from the decoded signal of the encoded data of the scramble signal in the storage means. Then, on the receiver side, the demodulated signal of the received signal and the decoded signal of the coded data of the scrambled signal in the storage means are subtracted or added to separate the scrambled signal, and the transmitted information is separated. An information signal having the same content as the signal is obtained.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 is the synchronization signal value), the synchronization timing signal (
A synchronization signal generator outputting c), encoded data (scramble data) of a scramble signal having a spectrum spread equal to or less than that of the information signal (a) to be transmitted by 2Vi.
A scramble data memory section 3 as a storage means for storing in advance decodes the encoded data (d) read out from the scramble data memory section 2 in response to the synchronization timing signal (c) from the synchronization signal generation section 1. 4 is an adder that adds the information signal (a) and the decoded signal (e), and 5 is a decoder that outputs the decoded signal (scrambled signal) (e); 5 is the adder that outputs the signal (f) from the adder 4; a transmitting section that transmits;
6 is a receiving section; 7 is a synchronizing signal detecting section that detects the synchronizing signal (b) from the signal (g) received and demodulated by the receiving section 6; and 8 is scrambled data having the same configuration as the scrambled data memory section 2. It is a memory section, and outputs encoded data (1) of the scramble signal according to the synchronization timing signal color detected by the synchronization signal detection section 7. 9 is a decoding unit that decodes this encoded data (i) and outputs a decoded signal (scrambled signal) O), and 10 is a subtraction unit that subtracts the decoded signal O) from the signal (g). Note that each of the units 1 to 5 is a transmitter, and each unit 6 to 10 is a receiver.

Next, the operation will be explained. The information signal (a) is input to the adder 4, and the encoded data (d) read from the scramble data memory section 2 in synchronization with the synchronization timing signal from the 1 synchronization signal generator 1 is further inputted to the decoder 3. The decoded signal (scrambled signal) (e) is input. Therefore, in the adder 4, the information signal (a) and the decoded signal (scrambled signal) (e) are added, and the transmitted signal (
f) to the transmitter 5 and sent to the receiver 6. At this time, before sending out this transmission signal (f), a synchronizing signal output from the synchronizing signal generating section 1 is sent to the receiving section 6.

On the other hand, the receiving section 6 receives the transmission signal (f) and outputs a demodulated signal (g), and the subtracting section 10. It is given to the synchronization signal detection section 7. The synchronization signal detection unit T outputs a synchronization timing signal (h) from the demodulated signal (g), and as a result, encoded data of the scramble signal is output from the scramble data memory unit 8 in synchronization with the synchronization timing signal (h). (i) is read out, which is then decoded by the decoding section 9 and given to the subtraction section 10 as a decoded signal (scramble signal) (''). The decoded signal (
j) is the same as the transmitting side decoded signal (,), and since the timing of addition and the timing of subtraction for the information signal (a) K are the same in synchronization with the synchronous timing signal ((ri), (h), Signal (goods) output from the subtraction unit 10
The same signal as the original information signal (a) is obtained.

In the above embodiment, the information signal transmission) and the decoded signal (e)
, (j) K is added on the transmitting side and subtracted on the receiving side, but as shown in FIG. The addition may be performed on the receiving side.

〔Effect of the invention〕

As described above, according to the present invention, a memory that stores encoded data obtained by encoding a scrambled signal having a spectrum spread equal to or less than that of the information signal transmitted by the concealing device at both the transmitter side and the receiver side. The transmitter side adds or subtracts the information signal to be transmitted and the scrambled signal from the storage means, and the receiver side adds or subtracts the received information signal and the scrambled signal from the storage means. Since the configuration is configured to obtain the same signal as the transmitted information signal by subtracting or adding the scrambled signal, the information signal can be scrambled without spreading the spectrum, and the encoded data of the scrambled signal can be Since it is easy to prepare, the device can be made at low cost and has the effect of providing strong secrecy.

[Brief explanation of the drawing]

FIG. 1 is a block connection diagram of a concealment device according to an embodiment of the present invention, FIG. 2 is a signal waveform diagram of each part thereof, FIG. 3 is a block connection diagram of a modified embodiment of this invention, and FIG. 4 is a conventional concealment device. The block connection diagram of the device, FIG. 5, is a signal waveform diagram of each part thereof. 1 to 5 are transmitters, 1 is a synchronization signal generation section, 2 is a scramble data memory section (storage means), 3 is a decoding section, and 4
is an adder, 5 is a transmitter, 6 to 10 are receivers, 6 is a receiver, 7 is a synchronization signal detector, 8 is a scramble data memory unit (storage means), 9 is a decoder, and 10 is a subtracter. It is. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Figure 1

Claims (1)

[Claims] A signal obtained by adding or subtracting a decoded signal of encoded data of a scrambled signal in a storage means that stores in advance encoded data of a scrambled signal having a spectrum spread equal to or less than that of the information signal to be transmitted and the information signal. Subtracting or adding a signal obtained by receiving a signal transmitted from a transmitter and this transmitter and demodulating the received signal, and a decoded signal of encoded data of the scrambled signal stored in advance in the storage means. a receiver that separates an information signal and a scramble signal in the received signal and outputs the same information signal as the transmitted information signal.