JPH05160829A - Isdn communication equipment - Google Patents

Abstract

PURPOSE:To attain data communication by sending communication data of the same content through the use of two B channels, allowing a reception terminal equipment to cipher a plain text and to compare the result with the communication data while the communication data are verified by both a caller side and a receiver side. CONSTITUTION:When a caller subscriber 21 outputs an important data communication request to a caller terminal equipment 22, the terminal equipment 22 generates a ciphering key use random number gamma as a call for using two communication channels and sends a setup message SETUP. A caller exchange 24 sends a similar setup message IAM. A called exchange 25 connects similarly the two communication channels to a called terminal equipment 27 to send a message SETUP. The terminal equipment 27 sends a reply message CNNECT together with the random number gamma received by the SETUP based on a communication enable notice from a subscriber 28, sends a ciphering key to a ciphering circuit 10, which is started, data of the communication channel are ciphered and compared with other data by a verification circuit 11, and then the communication attended with data verification is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used for verification of ISDN communication lines. In particular, it relates to a communication data verification method by encrypted communication of two B channel simultaneous connection calls.

[0002]

2. Description of the Related Art A conventional example will be described with reference to FIG. Figure 3
FIG. 3 is a block diagram of a conventional device and a diagram showing a communication signal form.

As is well known, ISDN has one D channel and two B channels, and communication data is normally transmitted and received by two B channels. The configuration of the device is as shown in FIG.

When verifying the state of the line, FIG.
As shown in FIG. 1, the input / output device 1 divides communication data into certain blocks, and a data verification code such as a parity bit calculated for each block is added before and after the communication data and transmitted. The code value calculated in 1 is compared with the data verification code to verify the line status based on the presence or absence of a data error.

[0005]

In this conventional communication line verification method, since the communication data and the verification data are transmitted on the same channel, the data length becomes long and the communication speed of the communication data itself decreases. It will be. That is, when the additional data for verification is small, the communication speed does not decrease so much, but the verification capability decreases, and when the additional data for verification is large, the communication speed decreases. Also, since the additional data for verification is generated and added by the software of each terminal,
There is a problem that terminals of different types cannot communicate with each other.

The present invention has been made against such a background, and an object of the present invention is to provide an ISDN communication device having a communication line verification means which does not reduce the communication speed and does not matter the type of the input / output device.

[0007]

SUMMARY OF THE INVENTION The present invention comprises an input / output device for performing ISDN communication, an input / output interface for connecting the input / output device, and each channel of ISDN connected to the input / output interface and each part of the device. A central control unit for controlling, a communication control unit connected to the central control unit for controlling B channel communication, and a channel for selecting and connecting two B channel signals to the communication control unit according to an instruction from the central control unit. In an ISDN communication device including a selection unit and a protocol processing unit that processes B channel and D channel protocols, the central control unit generates a cryptographic key for encrypting a signal to be transmitted to the B channel. And a memory means for storing the encryption key received from the B channel, wherein the channel selection section A means for encrypting one of the two transmitted B channel signals is compared with the received one pre-encrypted B channel signal and the other B channel signal encrypted after being received by the encrypting means. And means for verifying.

Further, it is preferable that the central control unit includes means for notifying the partner terminal of the verification mode in the setup signal.

The means for generating the encryption key may be configured by means for generating a random number.

[0010]

In performing important communication, when verifying the ISDN communication line, the communication data having the same content is used by using two B channels, one is encrypted and the other is not encrypted (hereinafter, Sent as plain text). The receiving terminal encrypts the plaintext sent using the encryption key received in advance and compares it with the communication data sent in advance encrypted to detect a data error. ..

Since the communication data of the same content is transmitted and received on the two B channels, it seems as if the efficiency is low, but since the data verification code is not added before and after the communication data, the length of the data can be minimized. Actually, more efficient data communication can be realized while verifying the communication line.

As a reason for encrypting one of them, if there is some abnormality in the communication line and communication data is rewritten due to a certain regularity, if plaintext is transmitted at the same time, both will be rewritten in the same way. , The data error cannot be found even if the two data are compared on the receiving side. Since the arrangement of "1" and "0" of the digital signal is changed by encrypting one side, even if the communication data is rewritten by a certain regularity,
If you verify it on the receiving side, the communication data encrypted plaintext,
The data content differs from the communication data that was originally encrypted and received, and a data error can be found.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the device of the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of a device according to an embodiment of the present invention and a diagram showing a communication signal form.

The present invention relates to an input / output device 1 for performing ISDN communication, an input / output interface 2 for connecting the input / output device 1, and an I / O device connected to the input / output interface 2.
A central control unit 3 that controls each channel of SDN and each unit of the device, a communication control unit 4 that is connected to the central control unit 3 and controls communication of the B channel, and two B channel signals are centralized in the communication control unit 4. In an ISDN communication apparatus including a channel selection unit 5 that is selected and connected according to an instruction from the control unit 3 and a protocol processing unit 6 that processes protocols of B channel and D channel, the central control unit 3 selects the B channel. The CPU 8 is provided with a means for generating an encryption key for encrypting a signal to be transmitted, and a memory 7 is provided as a memory means for storing the encryption key received from the B channel. An encryption circuit 10 as a means for encrypting one of the B channel signals is included, and one of the received pre-encrypted B channels is included. It is configured to include a verification circuit 11 as a means of comparison and verification of the other B-channel signal encrypted after receiving the channel signal and the encryption circuit 10.

Further, the CPU 8 of the central control unit 3 includes means for notifying the partner terminal of the verification mode in the setup signal.

The means for generating the encryption key is C
This is a configuration of a random number generating means in PU8.

As shown in FIG. 1 (b), the communication signal form by the device of the present invention sends communication data of the same content through two B channels, one of which is encrypted by the encryption line 10 and sent. It

Next, the operation of the apparatus of the present invention will be described with reference to FIG. FIG. 2 is a diagram showing the operation of the apparatus of the present invention.

When the calling subscriber 21 issues a request for performing important data communication to the calling terminal 22, the calling terminal 22 makes a random number r as an encryption key as a call using two communication channels. Then, the call setup message SETUP is transmitted together with these data. The originating exchange 24 which has received this also connects the two communication channels and transmits the same call setup message IAM. Called side exchange 2
Similarly, 5 connects two communication channels to the called terminal 27 and sends a call setting message SETUP. In response to the communication permission notification from the receiving side subscriber 28, the receiving side terminal 27 transmits a response message CNNECT together with the random number r which is the encryption key received in SETUP, and further sends the encryption key to the receiving side encryption circuit 10. By sending and activating, the unencrypted data on the communication channel side is encrypted, and the verification circuit 11 on the receiving side compares it with the other data to start communication with data verification. The reply message is sent together with the encryption key received from the receiving side terminal 27 through the receiving side exchange 25 and the transmitting side exchange 24 and the transmitting side terminal 2
2. The sender terminal 22 confirms that the keys match with this encryption key, activates the channel selection circuit 9 of the sender terminal 22, and activates the encryption circuit 10 together with the encryption key.

By the above procedure, it is possible to perform data communication while verifying the communication data at both the caller side terminal 22 and the callee side terminal 27.

[0021]

The communication line can be verified without lowering the communication speed and regardless of the type of input / output device.

[Brief description of drawings]

FIG. 1 is a block diagram of a device according to an embodiment of the present invention and a diagram showing a communication signal form.

FIG. 2 is a diagram showing an operation of the apparatus according to the embodiment of the present invention.

FIG. 3 is a block diagram of a conventional device and a diagram showing a communication signal form.

[Explanation of symbols]

 1 Input / output device 2 Input / output interface 3 Central control unit 4 Communication control unit 5 Channel selection unit 6 Protocol processing unit 7 Memory 8 CPU 9 Channel selection circuit 10 Encryption circuit 11 Verification circuit 21 Calling side subscriber 22 Calling side terminal 24 Calling Side switch 25 Called side switch 27 Called terminal 28 Called party r Random number

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Claims (3)

[Claims] 1. An input / output device for performing ISDN communication, an input / output interface for connecting the input / output device, and a central control unit connected to the input / output interface for controlling each channel of ISDN and each unit of the device. A communication control unit connected to the central control unit for controlling communication of the B channel, a channel selecting unit for selecting and connecting two B channels to the communication control unit according to an instruction from the central control unit, and a B channel and a D channel. In an ISDN communication device including a protocol processing unit that processes a channel protocol, the central control unit receives a signal from the B channel and a unit that generates an encryption key that encrypts a signal to be sent to the B channel. And a memory means for storing an encryption key, wherein the channel selection unit has two B channels for transmission and reception. And means for encrypting one of the signals, and means for comparing and verifying the one pre-encrypted B channel signal received and the other B channel signal encrypted after being received by said encrypting means. An ISDN communication device characterized by the above. 2. The ISDN according to claim 1, wherein the central control unit includes means for notifying the partner terminal of the verification mode in the setup signal.
Communication device. 3. The ISDN communication device according to claim 1, wherein the means for generating the encryption key is a random number generating means.