JPS61278256A - Cipher provision system of private branch electronic exchange - Google Patents

Abstract

PURPOSE:To suppress the cost rise due to the provision of a cipher provision circuit and a cipher decoding circuit at each terminal device requiring the provision of cipher by providing a circuit performing ciphering provision and ciphering decoding in a private branch of electronic exchange. CONSTITUTION:When a terminal device 151 requiring the provision of cipher dials a call number of a cipher trunk 110, a number of a cipher trunk 210 of an opposite station and a number of a terminal device 151 of the opposite party, a central processing unit 102 connects the cipher trunk 110 and the terminal device 151 via a channel switch 101. Further, the number of the cipher trunk 110 of the opposite station and the number of the opposite terminal device 251 are given to a trunk interface 114 through a trunk line of the ciphering trunk 110 at the same time. Then it is not required to provide the ciphering device for each terminal device and the number of cipher trunks is decided depending on the traffic requiring the cipher of content of communication. Since the cipher trunks and general trunk line trunks are used in common, data is sent without losing the instantaneousity as to a call requiring the instantaneousity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to communication concealment technology. In particular, the present invention relates to a method for providing a code for transmitting code signals by providing a code trunk in a private branch exchange.

〔overview〕

The present invention provides a central office line trunk that connects a public network within a private electronic branch exchange in a cryptographic system for a private electronic branch exchange that communicates using encrypted signals between arbitrary terminal devices housed in opposing private branch exchanges. It is also equipped with an encryption trunk that performs encryption and decryption, and controls the connection between the public network and the terminal device via the central office line trunk in the case of normal communication and the encryption trunk in the case of encrypted communication. , it is possible to add encryption as necessary without having to provide an encryption circuit and a decryption circuit for each terminal device, and without limiting the signals sent to the public network to encrypted signals. This is what I did.

[Conventional technology]

FIG. 3 is a block configuration diagram showing an example of a conventional encryption method. In FIG. 3, an encryption circuit 303 and a decryption circuit 304 are connected to a data signal input/output terminal 302 of a terminal device 301 that requires encryption. 305 to the public network 000. The public network 000 is connected to the decryption circuit 308 and the decryption circuit 309 via the private branch exchange 307 of the opponent station, and the decryption circuit 308 and the decryption circuit 309 connect the data signal input of the terminal device 311 that requires decryption. Output terminal 3
10, and encrypted signals are exchanged between the terminal devices.

Alternatively, encryption devices are centrally installed in the public network side input/output sections of the private electronic branch exchange 305 and the private electronic branch exchange 307.

[Problem that the invention seeks to solve]

In such conventional encryption methods, it is necessary to permanently connect an encryption circuit and a decryption circuit to all terminal devices whose communication contents must be kept confidential, which makes it difficult to reduce system costs when building an in-house communication network. There are drawbacks that contribute to the increase.

In addition, in the case of an in-house communication network, cost reductions can be achieved by centrally installing the encryption circuit and the decryption circuit in each unit at the connection between the in-house private branch exchange and the public network; Since all data signals are encrypted, there is a drawback that a delay occurs in data transmission in terminal devices that require immediacy, such as telephones, which do not particularly require confidentiality of communication contents.

The present invention solves these conventional drawbacks, and provides an electronic private branch exchange which is equipped with a circuit for assigning and decrypting codes in the private branch exchange, and is capable of carrying out encrypted communications in response to requests from terminal devices. The purpose is to provide a cryptographic assignment method.

[Means for solving problems]

The present invention provides office line trunks for the number of office lines connected to a public network, a communication path switch that connects the office line trunks and a plurality of terminal devices one-to-one, and a central office that controls the communication path switches. In a private electronic branch exchange equipped with a processing device,
A cryptographic trunk having a cryptographic assigning circuit and a cryptographic decoding circuit is provided, and when the terminal device performs cryptographic communication, the central processing unit includes a control means for connecting the terminal device and a public network via the cryptographic trunk. It is characterized by

[For production]

The present invention is equipped with a central office line trunk for connecting to a public network and a cryptographic trunk for encrypting and decrypting in a private electronic branch exchange.
The central processing unit of the private electronic branch exchange controls the connection between this terminal device and the public network via an encrypted trunk, while the central processing unit of the private electronic branch exchange at the other end uses encrypted communication commands sent via the public network. By controlling the connection between the public network and the terminal device to which the connection is requested via an encrypted trunk, encrypted communication can be performed between any terminal devices without having to provide an encryption circuit and a decryption circuit for each terminal device. be able to. Further, since terminal devices that do not require encryption can be connected to the public network via a normal central office line trunk, the immediacy of communication can also be ensured.

〔Example〕

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

FIG. 1 is a block diagram showing a first embodiment of the present invention. In FIG. 1, a plurality of terminal devices 1 are connected to private electronic branch exchanges 100 and 200 facing each other via the public network OOO.
50.151, . . . and 250.251, . . . are connected. The private electronic branch exchange 100 includes a call path switch 10
1, a central processing unit 102, a cryptographic trunk 110, and a plurality of central office line trunks 120, 121, . Private branch exchange 200 also has a similar configuration.

The connection example shown in FIG. 1 shows that the terminal devices 150 and 250 are terminals that do not require encryption, and the terminal devices 151 and 251 are terminals that require encryption, and that they are connected and in a conversation state. .

That is, the terminal device 150 is connected to the office line trunk 120 via the communication path switch 101, and
0 is the central office line trunk 22 of the game via the public network o o o
0, and the communication path switch 2 is connected to the office line trunk 220.
A terminal device 250 is connected via 01.

Further, the terminal device 151 is connected to the communication path interface 111 of the encryption trunk 110 via the communication path switch 101, and the communication path interface 111 is connected to the central office line trunk interface 114 via the decryption circuit 112 and the encryption adding circuit 113. is connected, the office line trunk interface 114 is connected to the office line trunk interface 214 of the encryption trunk 210 of the opponent station via public mooo, and the communication path interface 211 is further connected via the decryption circuit 212 and the encryption adding circuit 213. and the communication path switch 2 is connected to the communication path interface 211.
A terminal device 251 is connected via 01. Path switch 101.201 and crypto trunk 110.210
The central processing unit 102.202 is connected to the control interface 115.215.

A terminal device 150 housed in the private electronic branch exchange 100 that does not require encryption communicates with the terminal device 250 of the private electronic branch exchange 200 by transmitting the central office line calling identification number and the number of the central office trunk 220 of the opposite station. It becomes possible.

On the other hand, from the terminal device 151 that requires encryption, the calling number of the encryption trunk 110 and the encryption trunk 210 of the game player are sent.
number and the number of the other party's electric floor device 251, the central processing unit 102 connects the encryption trunk 110 and the terminal device 151 through the communication path switch 101, and also connects the encryption trunk 110 to the office line trunk interface 114. The number of the encryption trunk 210 of the opponent and the number of the terminal device 251 of the other party are given. The office line trunk interface 114 sends out the number of the encryption trunk 210 of the opponent station, calls the office line trunk interface 214 of the opponent station, and sends the outgoing signal from this office line trunk interface 214 back to the office line trunk interface 114. Then, this office line trunk interface 114 sends the number of the other party's terminal device 25 to the office line trunk interface 214 of the opposing party. After the central office line trunk interface 214 detects this number, it transmits this number to the central processing unit 202 of the private electronic branch exchange 200, and the central processing unit 202 issues an instruction to the call path switch 201 to connect the cryptographic trunk 210 and the terminal device 251. are connected, and encrypted signals are exchanged between the terminal device 151 and the terminal device 251.

Therefore, according to the method of this embodiment, it is not necessary to provide an encryption device for each terminal device, the number of encryption trunks can be determined depending on the amount of traffic that requires confidentiality of communication contents, and encryption trunks and general office line trunks can be used together. Therefore, data transmission can be performed without loss of immediacy even for calls that require immediacy.

FIG. 2 is a block diagram showing a second embodiment of the present invention. The second embodiment basically has the same configuration as the first embodiment, but the first embodiment has encryption trunks 110 and 210.
These central office line trunk interfaces 114.214 are equipped with central office line trunk interfaces 114.214.
Whereas the office line connected to is limited to the transmission of encrypted signals, in the second embodiment, a second communication line interface 116.216 is provided in place of the office line trunk interface 114.214, Crypto Trunk 110.2
10 and the public network 000 is connected to the communication path switch 101.
201 and central office line trunks 121 and 221.

That is, a terminal device 150 that does not require encryption and is housed in the private electronic branch exchange 100 connects to the central office line trunk 120 or 121 depending on the availability of the central office line trunk, and communicates with the private electronic branch exchange 200 of the other office via the public network 000. It is possible to communicate with the terminal device 250 that does not require encryption by connecting to the central office line trunk 220 or 221 of the terminal.

On the other hand, when the terminal device 251 that requires encryption first transmits the encryption trunk calling number and the encryption type number, the central processing unit 102 connects the communication path interface 111 of the encryption trunk 110 to the terminal device 151 via the communication path switch 101. At the same time, the second communication path interface 116 is connected to the office line trunk 120 or 121 via the communication path switch 101, and the type and decoding of the encryption to be provided is transmitted via the control interface 115 of the encryption trunk 110. After instructing the type of cipher to be used, a transmission signal is sent to the terminal device 151, and the terminal device 151 sends out the other party's number. As a result, public network 0
00 to the office line trunk 220 or 221 of the private branch electronic exchange 200 of the opponent station, but if the office line trunk 220 or 221 of the private branch electronic exchange 200 of the opponent station receives the terminal number within a certain period of time, the office line trunk 220 or 221 is connected to the encryption trunk 210 via the communication path switch 201, and further connected to the terminal device 251 via the communication path interface 211 of the encryption trunk 210 and the communication path switch 210, and the communication between the terminal device 151 and the terminal device 251 is is carried out using encrypted signals.

Therefore, in the second embodiment, the encryption type can be selected, and since the office line is not limited to the transmission of the encryption signal, the usage efficiency of the office line trunk can be improved.

In addition, in this embodiment, if the transmission and reception of the encryption type, encryption key, partner terminal number, etc. necessary for the connection between encryption trunks is performed using the common line signaling method, it is possible to Connections can be made quickly.

In this way, within the private electronic branch exchange 100.200 there are the call path interfaces 111.116.211.216 to the call path switch 101.201 and the central processing unit 102.
．． By arranging the number of encrypted trunks having control interfaces 115 and 215 for 202 in accordance with the office line usage rate of encrypted signals, it is not necessary to provide an encrypting circuit and a decrypting circuit for each terminal device. Furthermore, by adding cipher type determination and cipher type control functions to the control interface 115.215 of the cipher trunk,
It is possible to automatically select and send a cipher that matches the cipher type of the other party.

〔Effect of the invention〕

As explained above, the present invention provides a circuit for decompressing and decrypting codes in a private electronic branch exchange.
It is possible to suppress an increase in cost due to providing an encryption circuit and a decryption circuit for each terminal device that requires encryption.

Furthermore, since terminal devices that do not require encryption can be connected to the public network via a normal office line trunk, the immediacy of communication can also be ensured.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention. FIG. 2 is a block diagram showing a second embodiment of the present invention. FIG. 3 is a block configuration diagram showing an example of a conventional encryption method. 000...Public network, 100.200...Private electronic branch exchange, 101.201...Call path switch, 102.
202...Central processing unit, 110.210...Encryption trunk, 111.116.211.216...Communication path interface, 112.212...Decryption circuit, 113.213...Encryption adding circuit , 114.214
... central office line trunk interface, 115.215.
...Control interface, 120.121.220.2
21... Office line trunk, 150.151.250.2
51...Terminal device, 301.311...Terminal device,
302.310...Data signal input/output terminal, 303.
309... Encryption adding circuit, 304.308... Encryption decoding circuit, 305.307... Private branch exchange. Patent applicant: NEC Corporation − Representative: Patent attorney Naotaka Ide.

Claims (1)

[Claims] (1) Office line trunks for the number of office lines connected to the public network, a call route switch that connects the office line trunks and multiple terminal devices on a one-to-one basis, and a central processing unit that controls the call route switches. A private electronic branch exchange equipped with a cryptographic trunk having a cryptographic assigning circuit and a decryption circuit is provided, and when the terminal device performs encrypted communication, the central processing unit communicates with the terminal device via the cryptographic trunk to the public. A method for assigning encryption to a private electronic branch exchange, characterized in that it includes a control means for connecting to a network.