JPS5944145A - Cipher communication system - Google Patents

Abstract

PURPOSE:To obtain a cipher communication system having improved service ability and using an opening key, by adding a function to send an opening key of an opposite terminal to an exchange. CONSTITUTION:In case of communication between terminals A and B, the terminal A sends the telephone number of the terminal B to the exchange 3. When receiving the telephone number, the exchange 3 reads out the opening keys of the terminals A, B from its internal number storing device and transmits the opening key of the terminal A to the terminal B and the that of the terminal B to the terminal A, respectively. The terminals A, B cipher and decode signals on the basis of the opening key received from the opposite terminal and the internal key of itself, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) The present invention relates to an exchange system, and more particularly, to an exchange system in which a terminal device and an exchange are equipped with an encryption device to conceal communication contents.

(2) Conventional technologies and problems Conventional encryption systems involve one-to-one communication or encryption of signals on a transmission path, and there was no integrated system that included exchange (i).Therefore, the frequency of use will increase in the future. When transmitting confidential information via an exchange system, it is necessary to uniquely encrypt the transmitted data, and the serviceability of communication processing is also poor.

(3) Purpose of the Invention The purpose of the present invention is to add a function for cryptography to an exchange, thereby providing cryptography 7 (7) with good serviceability using a public key.
The aim is to provide a communication system.

(4) Configuration of the invention [l11] In contrast to the distribution of the public key of a cryptographic system using the public rj'rJ key, when the exchange recognizes the other party, the mutual public key is transmitted between terminals. The encryption device is activated before starting communication, and the public key is handled by the exchange, so that the key can be updated at any time at the terminal1, ensuring the confidentiality of communication. In a system consisting of a terminal equipped with an encryption/decryption device and an exchanger that uses these devices, the public key of each terminal is kept on board the 3J [! If there is, the terminal sends the public key of the specified connection partner to the terminal that made the connection request, and also notifies the connection partner of the incoming call and sends the public key of the terminal that made the connection request. , is characterized in that it performs encrypted communication, and furthermore, when the power of the terminal is turned on, R of the terminal is generated by a random number generator installed in the terminal, and by informing the exchange of the public key 311! It is characterized by updating.

(5) Examples of practical application of the invention The present invention will be explained in detail below with reference to Examples.

FIG. 1 is a schematic diagram of the entire DaJ-7 stem to which the present invention is applied. In the figure, 1 (A, B.

C and D Luo terminals, 3 is a damper, 4 is a communication line between the refueling islands, and 2 is a communication line between the terminals and the converter V.

In this configuration, the configurations of the terminal side and the exchange side for performing the encrypted communication of the present invention are shown in FIGS. 2 and 3.

Configuration of the terminal in Figure 2 (mainly related to encryption)
, 10 is a power supply, 11 is an 11L power-on detection circuit,
12 is a random number generation circuit, 13-digit internal key generation circuit, 14 is a control device, 15 is a storage device, 16 is a key generation circuit, 17 is an encryption/sealing device, 18.19 is a control device side and an input 4'-
': fj:j % Switching circuit with output device side, 2o.

21 is an interface circuit with the exchange, 226J is an input device ij\, and 23 is an output device.

In the configuration of the exchange shown in Figure 3, 30.31 is an interface circuit with the pIM terminal or other exchange, and 32.33
34 is a control device;
5 is a control storage device, 36 is a number storage device, 37 is a state storage device, 38i is a call (communication) path switch for performing contact/kill between i lines, and 39 is a switch control device.

With the above configuration, when power is turned on at the terminal 1, the voltage of the power supply 10 is detected, and the power-on detection circuit 11 notifies the generation port v, :s 12 and the control number P114 as random numbers.

The control device 4 receives the public key generated by the internal A4 generation circuit 13 based on the control sequence stored in the storage device 15. After that, control device U: interface circuit 20.31 for transmitting the public key to the reversing machine.
Jl is notified to the control number @ 34 of the exchange via . In the switchboard fill+, the control device 34t performs the following operations based on the control/-sense stored in the device 35:
A public key sending permission signal is notified to the terminal side 4+41 device b-14 via the interface circuit 30.21, and 7.14 notifies the public key to 34 via the interface circuit 20.31. 34 stores the public U1 key in the public 6 storage area corresponding to the last number 6H in the permanent code storage device 36. This 1
The processing of L et al. is performed for each terminal.

Now, when a terminal attempts to make a call to terminal B, terminal A notifies the exchange of the telephone number corresponding to terminal B. The controller 34 of the exchange is connected to the interface circuit 152o.
, I received the phone number from 31 and received the status information u? 3
In step 7, check the status corresponding to the telephone number, and if the end B is empty, enter the end A, and read the public address of the end B from the number storage device 36 and send it. At the same time, Ir1Ai notifies terminal B of the transfer and sends the public key of terminal A, and changes the contents of the state storage device.

When terminal A receives the public key 4 of terminal B, it copies the control number "4141-J internal needle creation cycle j'ii 13 from 13" in section 1 end A to key creation 16 and the public key of terminal B. , to the secret key creation 16 (create the cipher fp code 64 and pass it to 17).

Terminal B also performs the same process and passes r- to 17. Terminal B
When the handler responds by cutting it into nine pieces, ? ! The tnio I3 control device 14 sends a response signal to the exchange, and the exchange (lake control 1
According to the sequence stored in 35, circuit 34 selects eggs, 1
End A.

A transmitter signal is sent to B and the switch control 39 is sent to A.

An instruction is issued to connect B, and the switch 38 connects the path. +i1. Ends A and B are communication; when a valid signal is received, the encryption/decryption device takes a margin time for the connection.
f! A star traverse is applied to f, 17, and the 45 code from the input device 22 is encrypted and sent out, and the received signal is passed to the decryption 1.2 output device 23.

In the above process, the operators of terminals A and R can communicate in the same way as normal telephone calls without being aware of encryption at all.

Similar processing is possible even in a connection that passes through multiple exchanges, for example, communication between A and 6, since public 8 can be delivered through communication between several exchanges.

(6) Effects of the Invention According to the present invention, the key can be distributed before the terminals enter the communication state, and the public 1 can be updated freely.
Terminal operators can communicate without being aware of ossification,
This will simplify processing and improve serviceability.

[Brief explanation of the drawing]

Figure 1 shows 4. of the exchange system. Fig. 2 is a diagram showing the basic configuration of the I/Ming machine, and Figure 3 is a diagram showing the configuration of the transfer machine of the present invention. 14.34: Control device-112: Disturbance U generation circuit, 13:
Internal 11 creation circuit, 1G = key creation circuit, 17: Encryption 1) Kossification system, 35: Control storage device, 36 2nd number n'IN,! ”: V'f.

Claims (2)

[Claims] (1) In a system consisting of terminals equipped with encryption/decryption devices and an exchange that connects them via text FA, the public key of each terminal is stored in the exchange, and when a connection request is received from the terminal, the public key is specified by the terminal. The connection is encrypted by sending the first public key to the terminal that made the connection request, notifying the other party of the incoming call, and sending the public key of the terminal that made the connection request. An encrypted communication method characterized by communication. (2) The outside of the terminal is characterized in that when the power of the terminal is turned on, a public key is generated by a random number generator installed in the terminal, and the key is updated by notifying the exchange of the public key. An encrypted communication method according to claim 1.