JPH01292924A - Privacy telephone set - Google Patents

Abstract

PURPOSE:To prevent uneasiness from being given to a user who execute a call to need high secrecy by showing that secret synchronizing operation and initial set operation is started to the user without fail when the call is started or a line trouble is recovered, etc. CONSTITUTION:A secret talking device is composed of a terminal equipment 10, a sound input and output part 11, an enciphering part 12, a decoding part 13, a synchronous control pattern generating part 14, a re-synchronization requesting pattern generating part 15, a synchronous control pattern detecting part 16, a busy signal detecting part 17 and a re-synchronization requesting pattern detecting part 18. When a caller calls a called person and waits for the called person, or, when secret synchronization is caused to run out by the line trouble, etc., and re-synchronization is obtained, the operation from the secret synchronization to initial set is displayed on the display of the terminal equipment 10. Accordingly, the user of the terminal equipment 10 can easily recognize the privacy telephone set is operated. Thus, the important call can be safely executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a secure communication device, and more particularly to a secure synchronization operation display of a secure communication device used in an automatic real-time telephone communication network such as a specific communication line.

[Conventional technology]

For example, in fields that require an extremely high degree of secrecy, even if a specific communication line is used, secret devices are used to prevent the contents of the call from leaking to the outside world, and even audio is encrypted to prevent calls from being made. There are cases where

Conventionally, this type of secret device has been designed to perform a secret synchronization operation and an initial setting operation necessary to operate the secret device so that the user using the terminal is not aware of the presence of the secret device. was no longer displayed on the above terminals.

[Problem to be solved by the invention]

By the way, it is unclear whether the conventional secret communication device actually performs the above-mentioned secret synchronization operation and initial setting operation.
This caused anxiety to users who made calls that required a high degree of secrecy.

SUMMARY OF THE INVENTION An object of the present invention is to provide a secure communication device that can reliably indicate to a user that a confidential synchronization operation and an initial setting operation have started at the time of starting a call or recovering from a line failure.

[Means to solve the problem]

A ring raw signal detection circuit detects a ringing signal that indicates that the other party's terminal is being called, which comes from the exchange, and a synchronization control pattern signal is sent to the other party based on the detection signal of this ring raw signal detection circuit. The device is equipped with a synchronization control pattern generation circuit for sending out a synchronization control pattern, and a secret synchronization operation indicator that indicates that secret synchronization has been established based on the detection signal of the calling signal and the synchronization control pattern signal.

C Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the secret communication device of the present invention, and FIG. 2 is a sequence diagram showing the operation of this secret communication device. Note that the state of the switch S1 in FIG. 1 indicates a standby state fl (31-a).

When the calling party picks up the handset (not shown) of the terminal 10, the privacy device 20 is connected to the local exchange (see Figure 2) and becomes ready for dialing, and when the calling party finishes dialing. The signal is relayed to the other party's exchange, and if the dialed party (called party) is not available, a ringing signal is sent back from the other party's exchange to the calling party.

This ringing signal is detected by the ringing signal detector 17, the switch S1 is changed to the 5t-c state, and the synchronous control pattern generator 14 sends a synchronous control pattern to the other party's exchange, and the ringing signal is Terminal 1 is sent via OR gate ○R2 and ORI using the detection signal as a trigger.
A confidential synchronous operation indicator made of a light-emitting diode or the like built into the o is turned on to inform the caller that the confidential communication operation has started, and after a series of initial operation settings are performed, the above-mentioned display is turned off. Due to the above-mentioned initial operation settings, switch S1 is set to S1.
The state changes to -d and prepares for the next call. Note that the synchronization control pattern here refers to a signal for confirming that it is okay to talk to each other between the calling side and the receiving side.

On the other hand, a confidential communication device having a configuration similar to the confidential communication device shown in FIG. 1 is also installed on the other party's side of the call. In addition, when the illustration of the other party's confidential communication device is omitted and the other party's constituent members are shown, the component numbers are marked with a circle, for example, [synchronization control pattern detection unit @].

On the other party's side, the synchronization control pattern sent as described above is detected by the synchronization control pattern detection unit ■, and this is displayed on the confidential synchronization operation display of the terminal 0, so that it can be displayed on the called party's side as well. It is possible to confirm that the confidential communication operation has started, and then the initial setting operation is performed in the same manner as described above, and then the confidential synchronization operation indicator is turned off.

Next, when the caller starts a conversation via the voice input unit 11, the voice signal is encrypted by the encryption unit 12 and sent to the other party's private communication device (2) via the switch Sl, the local exchange, and the other party's exchange. is sent.

Then, since the other party's initial settings have already been performed by receiving the synchronization control pattern as described above, the encrypted audio signal is input to the restoration unit 0, where it is restored to the original audio signal. Output to the audio input/output section■.

In this way, the calling party and the called party can talk, and both parties are using the terminal 1 that is currently in use.
0. It has been confirmed that ■ has entered confidential communication mode, so you can start important calls with peace of mind.

In addition, if a call that was started after confirming the confidential communication status as described above is temporarily interrupted due to a failure in the trunk line (for example, a specific communication line) and then resumed, the call will be restarted from the confidential communication device on the called party's side. A synchronization request pattern is sent, and this resynchronization request pattern is detected by the resynchronization request pattern detecting section 18 of the calling party's private communication device 20. This detection signal is sent to the synchronous control pattern generation section 14 via the OR gate ○R2,
Retransmit the synchronization control pattern. In this case as well, the confidential synchronization operation indicator is lit in the same way as described above to notify the caller that the confidential communication operation has started.

〔Effect of the invention〕

As explained above, according to the present invention, when the calling party is waiting to call the called party, or when resynchronizing after loss of privacy synchronization due to a line failure, etc., initial settings can be made from the privacy synchronization operation. Since it is possible to display up to
The user of the terminal can easily confirm that the confidential communication device is working, and can make important calls with peace of mind.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the privacy device of the present invention, and FIG. 2 is a sequence diagram showing the operation of the privacy device of the invention. 10...Terminal device, 11...Audio input/output section, 14...Synchronization control pattern generation section, 15...
...Resynchronization request pattern generation section, 16...Synchronization control pattern detection section, 17... Calling signal detection section, 18... Resynchronization request pattern detection section, 20...
...Secret device.

Claims (1)

[Scope of Claims] A ringing signal detection circuit that detects a ringing signal indicating that the other party's terminal is being called, which comes from an exchange; a synchronization control pattern generation circuit that sends out a synchronization control pattern signal, and a secret synchronization operation indicator that displays that secret synchronization has been established based on the detection signal of the calling signal and the synchronization control pattern signal. A secret communication device.