GB2336225A

GB2336225A - An in-line keyswitch for disabling computer keyboards or monitors

Info

Publication number: GB2336225A
Application number: GB9807829A
Authority: GB
Inventors: Douglas Makhija; Andrew Bristow
Original assignee: ITAL AUDIO Ltd
Current assignee: ITAL AUDIO Ltd
Priority date: 1998-04-09
Filing date: 1998-04-09
Publication date: 1999-10-13
Also published as: GB9807829D0

Abstract

A key-operated computer security device 8 is interposed between a computer 2 and a keyboard 6 and monitor 4. The device 8 has a secure housing accommodating switches which interrupt clock, data, or synch. signals unless a physical key is applied to the device 8. The key may be an electronic key and the device may include a touch key system, the device 8 storing a number of codes for selected users. The cable connections may be released only by use of a special tool. A tamper loop may be connected to a remote alarm. The tamper loop may respond to tampering with the key decoding logic, and voltages may be applied to the cables to allow disconnection to be sensed.

Description

2336225 COMPUTER SYSTEM SECURITY DEVICE The present invention relates to

security devices for computer systems.

Computer systems generally comprise a central processing unit (CPU) in its own housing connected by cabling to a plurality of peripherals such as a keyboard, a mouse, a visual display unit (VDU) and a printer.

Access to certain parts of the CPU are often inhibited by the need to input a password. In the event that the user is temporarily absent from his computer, there is a reluctance of the user to switch the system OFF, since on return to the computer, there is considerable delay due to warm-up time, booting time and time to input the password before the system is again ready for use. As a consequence, most users tend to leave the computer unprotected for short periods, during which time, the data can be accessed by unauthorised personnel.

Also password& tend to be less secure than physical keys and so password systems are generally less secure.

According to the present invention there is provided a computer system security device, comprising a unit providing a connection between a central processing unit and separate peripheral components, said device comprising switching means for interrupting at least one electrical path between the central processing unit and each of the peripheral components, and a key operated lock allowing the switch means to be operated to complete said electrical path only when the correct key is used.

A computer system security device embodying the present invention, will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:

Figure 1 is a block diagram of the system; and Figure 2 is a circuit and block diagram of the security device.

A computer system as shown in Figure 1, includes a central processing system 2 in its own housing, a separate video monitor 4 and a separate keyboard 6. A security device 8, in its own housing, provides a connection from the keyboard 6 to the CPU 2 and a connection from the monitor 4 to the CPU 2.

The original keyboard and monitor cables are used to connect them to the device 8 while extension leads are provided to connect the keyboard and monitor terminals on the CPU to the security device 8.

The connectors, at the opposite ends of the cables, are locked to their respective connections using security bolts or fixings (not shown) which need a special tool to remove them, thereby making it difficult to bypass the device with auxiliary cables.

The device is provided with a key socket which may comprise a mechanical lock but is preferably an electrical key lock.

The security device as shown more clearly in Figure 2, is essentially a switch which interrupts certain links between the CPU 2 and its peripherals. The links are selected so that the peripherals remain in an energised or stand-by phase but are disabled from active interaction with the CPU 2.

As shown in Figure 2, the cable from the CPU 2 to the monitor 4 has its horizontal synch wire and vertical synch wire interrupted by respective switches 10 and 12 while the cable from the CPU 2 to the keyboard has its clock pulse and/or data transmission wires interrupted bv switches 14 decoding logic of the correct 10 to 16.

and 16. The switches are operated by a key unit 18 which responds to the application electronic key to close all four switches The unit 18 responds to the reapplication or removal of the key to open all four switches 10 to 16. The key may be secured by an elongate member to the user so that if the user leaves the station, the key also has to leave.

The unit 8 also has a tamper loop system connected to a remote alarm (not shown).

The tamper loop system may respond to the key decoding logic unit being tampered with to generate an alarm. The tamper loop system is also coupled to certain wires of the cables attached to the security device to apply a voltage thereto. When one or more cables are disconnected, an electrical change takes place and by monitoring this change, an alarm can be generated to indicate that a cable has been disconnected.

The voltage applied to the cable is primarily provided from the CPU 4 but in the event that the CPU 4 is switched OFF a back up battery with a long life takes over.

Where the electronic key system comprises an electronic touch key system, the security unit 8 may be provided with a memory capable of storing a plurality of allowable codes so that the security device can be used by a plurality of different selected individuals, each with their own unique code.

Thus, when a user ceases to be authorised or loses their key, the memory can be accessed and that code deleted.

While the switches 10 to 16 are preferably electronic switches such as controlled diodes, they may, of course, be electromechanical switches such as relays.

The housing for the security device is a robust housing secured with tamper proof fixings to prevent access to the contents thereof.

1 i

Claims

1. A computer system security device, comprising a unit providing a connection between a central processing unit and separate peripheral components, said device comprising switching means for interrupting at least one electrical path between the central processing unit and each of the peripheral components, and a key operated lock allowing the switch means to be operated to complete said electrical path only when the correct key is used.

2. A device according to Claim 1, wherein said lock comprises an electronic lock.

3. A device according to Claim 2, wherein said electronic lock comprises a touch key lock.

4. A device according to any one of Claims 1 to 3, including an alarm system which responds to tampering by operating an alarm.

5. A device according to Claim 4, wherein said alarm system monitors at least one electrical path to the central processing unit and to each of said peripherals and triggers the said alarm when a said path is interrupted.

6. A device according to any preceding claim, wherein the connection between the device and the peripheral components and the central processing unit is provided by cable connections which are secured to corresponding connections with the aid of fastenings which - 6 can only be released with a special tool.

7. A computer system security device substantially as hereinbefore described, with reference to the accompanying drawings.