JPH03184455A - Radio telephone system with privacy telephone function - Google Patents

Abstract

PURPOSE:To improve privacy telephone performance and to simplify the re-setting of a privacy telephone key by performing the re-setting of a new privacy telephone key generated from a privacy telephone key generation circuit on a master device with a slave device by using an optical signal. CONSTITUTION:When the change of the privacy telephone key is instructed with the key input part 13 of the slave device 40 by an operator, the privacy key generation circuit 12 generates an appropriate privacy telephone key, for example, by generating a random number, etc., and it is registered on a memory circuit 11, The new privacy telephone key is inputted to a privacy telephone circuit 7, and following making of a telephone into the privacy telephone and decoding are performed with the privacy telephone circuit 7, and also, it is transmitted to the light reception circuit 5 of the master device 30 with a light transmission circuit 10 as the optical signal L. The master device 30 stores the privacy telephone key in a memory circuit 4, and following communication with the slave device 40 by radio W is made into the privacy telephone and decoded with a privacy telephone circuit 2. Even when a third party nearby is provided with the similar telephone system, no influence on the master device of the third party is applied since light is shielded, which prevents tapping performed.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an indoor wireless telephone system with a secret call function, and particularly to a wireless telephone system for transmitting and receiving voice signals indoors to a master device connected to a public telephone line. The present invention relates to a wireless telephone system with a privacy function that makes communications between child devices private.

[Prior Art] In general, an indoor wireless telephone system is composed of a master device connected to a public telephone line and a slave device that transmits and receives audio signals to and from the master device by radio. A telephone call is made by a parent device transmitting and receiving a telephone call to and from a slave device.

Conventional wireless telephone systems allow cordless calls indoors, but there is a possibility that a third party using a nearby wireless telephone system using the same frequency may eavesdrop on the call. A confidential function is provided to limit the parent device and child devices.

Note that the technology related to the secret function is disclosed in Japanese Patent Application Laid-open No. 61-1.
The technique described in Japanese Patent No. 98837 can be mentioned.

[Problems to be Solved by the Invention] In the conventional wireless telephone system with a secret function, a secret key is fixedly set in advance in each of the parent device and the child device of χJ, so it is not possible to simply change the secret key. There was a problem in that it was not possible to do so, and confidentiality was insufficiently ensured.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the problems caused by the prior art, and to provide a wireless telephone system with a privacy function that improves confidentiality and simplifies resetting of a privacy key.

[Means for Solving the Problems] In order to achieve the above object, the wireless telephone system with a privacy function according to the present invention is such that a parent device privatizes an audio signal sent via a public telephone line using a privacy key, and A confidential communication circuit that decodes a polarized audio signal sent from the device, a parent memory circuit that stores a confidential key of the confidential communication circuit, and an optical receiving circuit that receives the confidential key by an optical signal and sends it to the parent memory circuit. , a child confidential speech circuit in which the child device decodes the polarized audio signal from the parent device and polarizes the audio signal transmitted to the parent device, and a child memory circuit that stores the confidential speech key of the child confidential speech circuit. The device is configured to include a secret key generation circuit that generates and sends a secret key to the child storage circuit, and an optical transmission circuit that transmits the secret key to an optical receiving circuit of the parent device by an optical signal.

[Function] In the wireless telephone system with a secret function configured in this way, the slave device stores a new secret key generated by the secret key generation circuit in the slave memory circuit, and also uses an optical signal by the optical transmission circuit to transmit the new secret key to the parent device. By storing it in the parent memory circuit of the optical receiving circuit of the device, polarizing and decoding the audio signal, and resetting the confidential key via the optical signal, it improves confidentiality and simplifies the private key resetting. can be converted into

[Embodiment] Hereinafter, an embodiment of a wireless telephone system with a secret call function according to the present invention will be described in detail with reference to FIG.

FIG. 1 is a diagram for explaining a wireless telephone system with a confidential call function according to this embodiment.
0 is connected to a parent device 30, and a child device 40 that communicates with the parent device 30 by radio waves W.

The parent device 30 includes an interface circuit 1 that uses a telephone line 20 as a human power source, and a privacy circuit 2 that polarizes the voice signal received via the line 20 and decodes the polarized voice signal from the slave device 40. , a transmitting/receiving circuit 3 that transmits and receives a polarized audio signal to and from the slave device 40 via the antenna 21, an optical receiving circuit 5 that receives a private key using an optical signal, which will be described later, and the optical receiving circuit 5. It includes a storage circuit 4 that stores the received secret key and outputs it to the secret key circuit 2.

Furthermore, the child device 40 communicates with the parent device 30 via i+Jl.
a transmitting/receiving circuit 6 that transmits and receives a polarized audio signal via an antenna 22; a transmitter 9 that inputs the transmitted voice Sd of the operator and outputs the audio signal; and a transmitter 9 that receives the audio signal from the parent device 30. A telephone receiver 8 that outputs the voice Su to the operator, a key manual section 13 that instructs resetting of the secret key according to the operator's operation, and a secret key generation circuit 12 that generates a new secret key according to instructions from the input section 13. and a storage circuit 1 that stores the new secret key sent from the secret key generation circuit 12.
1, the new secret voice key from the memory circuit 11 is used manually to decode the secret voice signal received by the transmitter/receiver circuit 6 and output it to the receiver 8, and the voice signal from the transmitter 8 is polarized and transmitted/received. It is composed of a private message circuit 7 that outputs the secret message to the circuit 6, and an optical transmitting circuit 10 that transmits the new confidential message key stored in the storage circuit 11 to the optical receiving circuit 5 of the parent device 30 by means of an optical signal. It is assumed that the secret key is initialized in advance in each storage circuit 4 and 11 at the time of shipment of each device.

Now, in the wireless telephone system with a confidential communication function configured in this way, when a call is made to an external party using the slave device 40 through the public telephone line 20, the voice signal from the other party is transmitted via the interface circuit 1 to the confidential communication circuit 2. The transmitter/receiver circuit 3 polarizes the signal and transmits it to the child device 40 via the antenna 21.

In the child device 40, the polarized audio signal received by the antenna 22 and the transmitting/receiving circuit 6 is decoded by the polarizing circuit 7, and the receiver 8 emits the received audio Su to the operator.

Transmitted voice Sd by the operator is polarized by the privacy circuit 7 via the transmitter 9, and then transmitted to the antenna 21 of the parent device 30 by the transmission/reception circuit 6 and antenna 22. This polarized audio signal is received by the transmission/reception circuit 3, decoded by the polarization circuit 2, and then decoded by the interface circuit 1.
It is sent to the public telephone line 20 by.

Although the present wireless telephone system with a secret function normally operates in this manner, the operator can reset the initially set secret key at any timing. The resetting of this secret key will be described in detail below.

First, when the operator instructs to change the secret key using the key manual section 13 of the child device 40, the secret key generation circuit 12 generates a suitable secret key by, for example, random number generation, and registers it in the storage circuit 11. This new secret key is input to the secret circuit 7 and
Subsequent polarization and decoding are performed by the optical transmission circuit 10, and the signal is transmitted as an optical signal to the optical reception circuit 5 of the parent device 30. The parent device 30 inputs the new secret key into the optical receiving circuit 5 by the optical signal, stores the secret key in the storage circuit 4, and uses the new secret key in the secret key circuit 2 for subsequent communication with the child device 40 by wireless W. This is done by polarizing and decoding using a key.

In this manner, the wireless telephone system with a secret function according to the present embodiment operates to reset a new secret key in the parent device 30 by means of an optical signal from the child device 40 side.

Therefore, in this system, since the new confidential key is transmitted from the slave device 40 using an optical signal, it is necessary to reconfigure the parent device 30 and the slave device 40 in close proximity. Even if you have a similar telephone system, since the light is blocked, it will not affect the master device of a third party, and eavesdropping can be prevented. In particular, if the operator frequently changes the secret key, the risk of eavesdropping by a third party can be reduced.

In the wireless telephone system with a secret function in this embodiment, an example has been described in which a secret key is set from the child device side, but it may be configured so that the parent device sets a secret key in the child device. , and the optical signal may also be a signal that can be physically blocked. Furthermore, it is also possible to configure the device to automatically reset the confidential key at regular intervals without depending on an operator's instructions.

[Effects of the Invention] As described above, in the wireless telephone system with a secret key function according to the present invention, the slave device uses an optical signal to reset the new secret key generated by the secret key generation circuit to the parent device, thereby allowing the slave device to generate a secret key by using an optical signal. This makes it possible to improve security and simplify confidential key resetting.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining a wireless telephone system with a secret function according to an embodiment of the present invention. 1: Interface circuit, 2: Secret communication circuit, 3: Transmission/reception circuit, 4: Memory circuit, 5: Optical reception circuit, 6: Transmission/reception circuit, 7: Secret communication circuit, 8: Receiver, 9: Transmitter, 10: Optical transmission Circuit, 11: Memory circuit, 12: Secret key generation circuit, 13
: Key personnel department, 20: Telephone line, 21 and 22: Antenna.

Claims (1)

[Scope of Claims] A wireless telephone system with a privacy function in which a parent device connected to a public telephone line transmits and receives a private voice signal to a slave device using radio waves, the system comprising: A parent secret speech circuit that polarizes the speech signal using a secret key and decodes the polarized audio signal sent from the child device; a parent memory circuit that stores the secret key of the parent speech circuit; a parent device including an optical receiving circuit that sends it to a storage circuit; a child confidential speech circuit that decodes the confidential audio signal from the parent device and polarizes the audio signal to be transmitted to the parent device; and a confidential communication circuit of the child confidential speech circuit. A child memory circuit that stores a key, a secret key generation circuit that generates and sends a secret key to the child memory circuit, and an optical transmission circuit that transmits the secret key to an optical receiving circuit of a parent device by an optical signal. a device, the slave device stores a new secret key generated by the secret key generation circuit in the slave memory circuit, and transmits the secret key received by the optical receiver circuit of the parent device to the parent device using an optical signal by the optical transmission circuit. A wireless telephone system with a privacy function, characterized in that it is stored in a memory circuit to polarize and decode voice signals.