JPS6213867B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a secure connection system, and more particularly to a secure connection system in which a data processing system using a switched line network is provided with a security function. A general secure connection system achieves the security function by preventing any terminal from accessing the data processing system through a switched line network.

For example, when maintenance of a data processing system can be performed from a maintenance center through a switched line, access to the data processing system from terminals other than the maintenance center is prevented.

Conventional secure connection systems have adopted a password method. In this password method, a password is set that is known only to the terminal that is authorized to access the central processing unit and the central processing unit being accessed, and when connecting to the central processing unit, the terminal that is attempting to access the The central processing unit to be accessed compares it with a pre-stored password to see if it is the default password, and if the password is other than the default password, it cancels the connection with the central processing unit and stops accessing the data processing system. This is a method to suppress

With this password method, if the password itself is known to a third party, the third party can use this password to access the data processing system from any terminal other than the terminal that is authorized to access, such as at a maintenance center. The disadvantage was that the security function was incomplete because the security function became insufficient.

An object of the present invention is to provide a secure connection system with more complete security protection functions.

The secure connection system of the present invention includes a called storage means for storing a call from a called terminal, a telephone number storage means for a predetermined re-calling terminal, and a predetermined telephone number storage means for storing a call from a called terminal. calling means for issuing a call to a recall terminal in accordance with the telephone number stored in the telephone number storage means; and a connection for connecting the recall terminal and a central processing unit in response to the call origination. It consists of means.

According to the present invention, when a data processing system receives a call from a terminal other than a predetermined terminal whose telephone number is known in advance, the telephone is temporarily disconnected and a call is returned based on the previously known telephone number. It is based on the principle that since only the default terminal is called when re-calling, a third non-default terminal is not connected to the central processing unit and therefore cannot physically access the data processing system. .

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a terminal device 10 to which access is not permitted, a maintenance center 20 to which access is permitted, a switched line network 30, a network control device 40, and a modem device 50 in one embodiment of the present invention. ,
Access right check device 60 and communication control device 7
0 and a central processing unit 80.

When accessing the central processing unit 80 from the maintenance center 20, the maintenance center 20 first calls the central processing unit 80 via the switched line network 30, and hangs up after a certain period of time.

The modem 50 turns on the called indication signal 51 to the access right checking device 60 in order to report the incoming call to the central processing unit 80 .

The access right checking device 60 does not directly transmit the called indication signal 51 to the central processing unit 80, but uses the called detection circuit 62 to transmit the called indication signal 51 to the central processing unit 80.
1 is turned on, and then when the call from the maintenance center 20 is immediately hung up and the called display signal 51 turns off, the called memory flip-flop 63 is turned on and the called terminal The received call from the maintenance center 20 is stored.

When called storage flip-flop 63 is turned on, data terminal ready signal 53 is turned on through OR circuit 64. In this state, in response to the memory of the called call, the automatic return telephone circuit 61 transmits the pre-known telephone number of the maintenance center 20, that is, the telephone number of the predetermined repeat call terminal, to the network via the number information signal group 43. It is sent to the control device 40 and a call is made to the maintenance center 20 again.

When the maintenance center 20 picks up the incoming call, the network control device 40 detects that the call has been picked up and sends a line connection command signal 41 to the modem 50 and a connection completion signal 4 to the access right check device 60.
Turn on 4.

In the modem 50, since the data terminal ready signal 53 from the access right check device 60 is already turned on, when the line connection command signal 41 turns on, the data set ready signal 52 to the access right check device 60 is turned on. do.

In the access right checking device 60, since the called storage flip-flop 63, the connection completion signal 44, and the data set ready signal 52 are on, the called display signal 67, which is the output of the AND circuit 65, is turned on. . This called display signal 67 passes through the communication control device 70 to notify the central processing unit 80 that a call has been received from the maintenance center 20.

When the software of the central processing unit 80 is notified of the incoming call, it turns on the data terminal ready signal 68 and causes the access right checking device 60 to turn on the data terminal ready signal 68.
After notifying that the telephone call has been accepted, it is detected that the data set ready signal 66 is on. When the data terminal ready signal 68 turns on, the access right check device 60 resets the called storage flip-flop 63 and outputs the AND circuit 65.
The called display signal 67, which is the output of the terminal, is turned off.

When this series of operations is completed, data transfer becomes possible, and communication is started between the central processing unit 80 and the maintenance center 20 through the modem interface signal group 69.

Note that the modem device 50 and the communication control device 70
The above processing in the central processing unit 80 and the software of the central processing unit 80 is exactly the same as when the access right checking device 60 is removed.

Next, a case will be described in which a third party accesses the central processing unit 80 from the terminal device 10 which is a terminal other than the maintenance center 20 and is not permitted to access.

When a call is made from the terminal device 10, which is the called terminal, to the central processing unit 80 and the call is hung up after a certain period of time has elapsed, the access right check device 60 uses the automatic callback telephone circuit 61 to call the re-calling terminal again. Become. However, since the telephone number to be dialed at this time is the pre-known telephone number of the maintenance center 20, that is, the telephone number of the re-call terminal, the telephone number will not be dialed from the terminal device 10 that has been sent to the maintenance center 20 and is not authorized to access it. . Therefore, since there is no physical telephone connection to the central processing unit 80 from the terminal device 10 which is a terminal other than the maintenance center 20, communication becomes impossible.

In the above embodiment, an example was shown in which the access right check device 60 including the called storage means and the calling means is provided between the modulation/demodulation device 50 and the communication control device 70. The calling means is an additionally provided access right check device 6.
0, the modem 50 and the communication control device 7
Further, it may be provided in the network control device 40, the central processing unit 80, etc., regardless of the presence or absence of the modem device 50 and the communication control device 70.

Further, in the above embodiment, only the maintenance center 20 is shown as the re-call terminal, but it may be a plurality of terminals. In this case, the object of the present invention can be fully achieved by recognizing which terminal is the called terminal using a password or other means and calling the corresponding re-calling terminal.

The secure connection system of the present invention compares a pre-stored password with the password from the called terminal, and when they match, responds to the called terminal's memory instead of connecting the called terminal and the central processing unit. By connecting a predetermined re-call terminal to the central processing unit, it is possible to separate the called terminal and the terminal connected to the central processing unit so that it is not connected to any other terminal, thereby protecting security. This has the effect of making it more complete.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. 10...Terminal device, 20...Maintenance center, 30
...Switched line network, 40...Network control device, 41...
Line connection command signal, 42...Network control device interface signal group, 43...Number information signal group, 44...
... Connection completion signal, 50 ... Modulation/demodulation device, 51, 6
7... Called indication signal, 52, 66... Data set ready signal, 53, 68... Data terminal ready signal, 54, 69... Modem/demodulator interface signal group, 60... Access right check device, 61
. . . Automatic return telephone circuit, 62 . . . Called detection circuit, 63 . . . Called memory flip-flop, 64 .
... OR circuit, 65 ... AND circuit, 70 ... Communication control device, 71 ... Communication control device interface signal group, 80 ... Central processing unit.

Claims (1)

[Claims] 1. A called storage means for storing a call from a terminal, a telephone number storage means for a predetermined re-calling terminal, and a storage means for storing the telephone number in a predetermined re-calling terminal in response to the memorization of the called. The device is characterized in that it includes a calling means for generating a call in accordance with a telephone number stored in the means, and a connecting means for connecting the re-call terminal and a central processing unit in response to the calling. Confidential connection system.