JPH03233755A - Variable exchange system for cross id - Google Patents

Abstract

PURPOSE:To prevent a transmitting/receiving telegraphic message of cross ID exchange on a circuit from being stolen by a third party by some means by making the cross ID variable at every circuit connection. CONSTITUTION:In the case of exchange of a cross ID to which each electronic computer connected by a public communication circuit verifies each connection validity immediately after the circuit connection, the cross ID, for instance, XB1 is changed to a new cross ID, XB2 at every circuit connection, and at the time of executing the circuit connection in the next time, the new cross ID, that is, XB2 is exchanged so as to verify each connection validity. In such a way, it can be prevented that a transmitting/receiving telegraphic message of cross ID exchange on the circuit is stolen by a third party by some means, or in the case a value of the cross ID leaks, it is prevented that an electronic computer of a third party which is not to be connected is connected as an outgoing side electronic computer.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cross ID variable exchange method, and in particular, a cross ID variable exchange method performed immediately after line connection [Prior Art] In the conventional cross ID exchange, The sending computer stores the cross ID to be sent to the receiving computer in a file in the main storage device or magnetic disk storage, while the receiving computer stores the cross ID to be sent to the receiving computer. Multiple cross IDs are stored in a file in the main storage device or magnetic disk device, and when the receiving computer receives the call and the line is physically connected and transmission/reception is possible, the computer transmits the cross ID to the sending computer. A cross ID transmission/reception request message (cross ID command) is transmitted to the cross ID transmission/reception request message (cross ID command). Next, the sending computer reads the cross ID to be sent from a file in the main storage device or magnetic disk in response to the above-mentioned cross ID transmission request message (cross ID command), and transmits it to the receiving computer.

The computer on the receiving side uses the cross ID sent from the computer on the calling side as a key to search for files in the main storage device or magnetic disk, and if a matching cross ID is found, it determines that the connection is permitted. The subsequent transmission/reception processing begins. If a matching cross ID is not found, it is determined that the connection is not permitted and the line is disconnected.

As explained above, the transmitting computer receives the cross ID stored as a fixed value in a file in the main storage device or magnetic disk device each time a line is connected. Send to electronic computer.

[Problem to be solved by the invention]

In the conventional cross ID exchange described above, the cross ID sent from the sending computer is always a fixed value, so
If the transmitted and received messages for Cross ID exchange on the line are stolen by a third party by some means, or if the value of the Cross ID is leaked, the computer of the third party that should not be connected becomes the sending computer. There is a drawback that the connection is made by using the cross ID.

SUMMARY OF THE INVENTION An object of the present invention is to provide a variable cross ID exchange system that improves the above-mentioned drawbacks by automatically changing the cross ID.

[Means to solve the problem]

The cross ID variable exchange method according to the present invention is a method for exchanging cross IDs in which computers connected via a public communication line verify the validity of each other's connection immediately after the line is connected.
This is realized by changing the cross ID to a new cross ID each time a line is connected, and exchanging the new cross ID when connecting the line next time to verify the validity of each other's connections.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is an explanatory diagram showing one embodiment of the present invention. In the figure, before the line is connected, XBI is registered in the cross ID management table 2 of the computer on the receiving side as the cross ID sent from the computer on the calling side. The ID file 4 stores XBI as the cross ID to be transmitted.

The originating computer sends a message to the receiving computer via the public communication network, and when the line is connected and transmission/reception is possible, the Cross ID generation program 1 of the receiving computer sends a Cross ID transmission request message (Cross ID command). )
(Step 11) 0 When the cross ID generation program 3 of the sending computer receives the above cross ID transmission request message (cross ID command), it retrieves the cross ID XBI to be transmitted from the cross ID file 4.Step 12) Send to the receiving computer (step 13)
Then, the conversion function is used to convert XBI to XB2, and XB2 is registered in the cross ID file 4 as the cross ID to be transmitted at the next cross ID exchange (step 14).

On the other hand, the cross ID generation program 1 of the receiving computer
When receives XBI as cross rD, “cross ID
A search is made to see if the XBI exists in the management table 2 (step 15), and if the XBI is found, the connection is permitted.

And the cross ID generation program 3 of the sending computer
XBI using the same conversion function used in
is converted to XB2, the cross ID management table 2 is updated (step 16), and the process moves on to the subsequent transmission/reception processing.

The next time you connect the line, use XB2 as the cross ID.

〔Effect of the invention〕

As explained above, by making the cross ID variable for each line connection, the present invention prevents the transmission and reception of cross ID exchange messages on the line from being stolen by a third party, or the value of the cross ID being changed to a third party. Even if the information is leaked to a third party, it has the effect of preventing connection to a third party's computer that should not be connected.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the present invention. DESCRIPTION OF SYMBOLS 1...Cross ID generation program of the receiving side computer, 2...Cross ID management table, 3...Cross ID generation program of the sending side computer, 4...Cross ID file.

Claims (1)

[Claims] When computers connected via a public communication line exchange cross IDs to verify the validity of each other's connection immediately after the line is connected, the cross ID is changed to a new cross ID each time the line is connected, and then the line is connected. A variable cross ID exchange method characterized in that the new cross ID is sometimes exchanged to verify mutual connection validity.