GB2390205A

GB2390205A - Security code transmitter

Info

Publication number: GB2390205A
Application number: GB0214185A
Authority: GB
Inventors: Derek Witherington
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-06-20
Filing date: 2002-06-20
Publication date: 2003-12-31
Also published as: GB0214185D0

Abstract

Security devices consist of a transmitter (1) and a receiver (2) for receiving and responding to signals from the transmitter (1), the transmitter (1) including a code entry device (3) for receiving a code to which the receiver (2) responds, a code generator (4) for generating code received from the device (3), an output device (6) for transmitting generated code to the receiver(2), a feedback loop (7) for passing code from the generator (3) to the code entry device (3) to maintain code generation by the code generator (4), and means (8, 9) whereby the loop (7) can be physically broken to cause the code generator (4) to cease generating the code. Such devices can be used to protect other devices against unauthorized access and/or to allow authorised access by bringing the transmitter (1) and the receiver (2) into communicating proximity whilst denying access to an authorized user following breaking of the loop (7).

Description

1 - Security Systems This invention concerns security systems, for example

for controlling access to secure areas of buildings or to electronic equipment. Access control to secure areas of buildings, for example offices in banks, or the like, or store rooms in shops selling expensive equipment such as computers, is often effected by keying in a numeric security code into a lock via a key pad of which unlocks the lock when the correct code is inserted, by inserting a card with a magnetic strip carrying a suitable magnetic code to unlock the lock, or by conventional locks and keys.

All of these methods suffer with the disadvantage that they are not hands free. Furthermore, using a key pad is only effective if the code remains unknown to those to whom access is to be denied, and unless such codes are changed regularly there becomes an increasing risk with time that a determined intruder will see the correct code being entered and subsequently use it to gain access to the secure area. Changing the code will reduce this risk, but it then presents problems for those who

- 2 should have access to the secure area, for example due to the new code being forgotten or the change taking place over a holiday period.

Denying access by unauthorized access to computers presents different problems. For example, although entering a security code or password into a computer before it can be used will deter some, people with sufficient knowledge can avoid such codes. Furthermore, such codes are ineffective once a person authorised to access the computer has entered the correct code and the authorized user moves away from the computer.

According to the present invention there is provided security device comprising a transmitter and a receiver for receiving and responding to signals from the transmitter, the transmitter including a code entry device for receiving a code to which the receiver responds, a code generator for generating code received from the code entry device, an output device for transmitting generated code to the receiver, a feedback loop for passing code from the code generator to the code entry device to maintain code generation by the code generator, and means whereby the feedback loop can be physically broken to cause the code generator to cease generating the code.

Security devices in accordance with the present invention can be arranged to function in a variety of ways In one way, access to a protected device can be controlled by the transmitter and receiver being in communicating proximity to each other. For example, access to a computer or a cash register can be denied to third parties merely by an authorized person carrying the transmitter moving out of range of the receiver controlling the computer or cash register, the computer or cash register then being reactivated by the transmitter being brought back into range of the receiver by the authorised user.

Breaking the feedback loop, for example in response to physical threats to the authorised user, would then prevent the

3 - transmitter from generating the coded signals required by the receiver to activate the computer or casn register.

Another mode of operation would be to permit access to buildings or certain specific areas within buildings. Different codes could then be used to control such access, for example access could be allowed on one day but not another. Breaking of the feedback loop could then be used as a panic device to prevent unauthorized by third parties.

A further mode of operation would prevent third parties from removing equipment from a person carrying it. This could be effected by the receiver providing signals to maintain the equipment in a functioning mode whilst signals are received from the transmitter, but to be inactivated if coded signals from the transmitter are no-longer received by the receiver.

Embodiments of security device in accordance with the present invention will now be described with reference to the accompanying diagrammatic drawings in which: Fig. 1 is a schematic diagram of a first embodiment) and Fig. 2 is a schematic diagram of a second embodiment.

The embodiments shown in Figs. 1 and 2 are substantially identical and so similar parts are identified by the same reference numerals in each case.

Referring to the drawings, the security devices both consist of two parts, a transmitter shown generally at 1, and a receiver shown generally at 2, communication between the transmitters 1 and the receivers 2 differing in the two embodiments.

The transmitter 1 shown in Fig. 1 consists of a code entry device 3, a code generator 4, a timer 5, and an output device 6 in the form of a radio frequency transmitter. An electrical loop 7 forms a connection between the code generator 4 and the

4 - code entry device 3, the connection being via a plug 8 and socket 9, the latter being connected to the code generator 4 by a line 10.

The loop 7 can take various forms according to how the transmitter l is to be worn by the user, for example it can be in the form of a strap, a neck chain or a bracelet, In use, the transmitter 1 is attached to the user using the loop 7, and a security code is entered into the code entry device 3 which then activates the code generator 4. Signals from the code generator 4 are fed via the line 10 through the socket 9, the plug 8, and the loop 7 back to the code entry device 3, thereby maintaining code generation by the code generator 4.

The timer 5 also receives the coded signal from the code generator 4, the timer 5 serving to produce pulses of the code at regular time intervals, for example every few seconds. The pulsed coded signals from the timer 5 are then passed to the output device 6 which in the case of Fig. 1 produces a short range radio frequency transmission, for example over a range of 3m or less. The frequency of the transmission can obviously be selected as required, for example it can be of the order of 434MHz. The receiver 2 shown in Fig. 1 consists of a radio frequency receiver 11, a decoder 12, a timer 13, and a switch/relay 14, the device to be locked by the security device being shown at 15. When the radio frequency receiver 11 receives a coded radio frequency signal from the transmitter l, the signal is fed to the decoder 12. If the decoded signal is identical to that required to operate the device 15, it is passed via the timer 13, which operates for a period which is twice that of the timer 5, to the switch/relay 14 which then actuates the device 15.

The device 15 can take various forms, for example it can be an electronic door lock or a computer dangle.

- 5 - As will be appreciated, if the connection between the code entry device 3 and the code generator 4 via the loop 7 is broken, for example by unplugging the plug 8 from the socket 9, or by cutting the loop 7, the code entry device 3 will stop sending coded signals to the output device 6. Furthermore, reconnecting the plug 8 and the socket 9, or reconnecting the cut ends of the loop 7, will not activate the transmitter 1 because the code originally entered into the code entry device will have been lost. The transmitter 1 can then only be made to operate the device 15 connected to the receiver 2 by re-entry of the necessary code into the code entry device 3, and this can be done by a third party so that the wearer of the transmitter 1 need not know the appropriate code.

Security devices described with reference to Fig. 1 can be used in a variety of situations where activation of a device is desirably effected by the user being in the proximity of the controlled device, and they overcome many of the disadvantages of hitherto proposed security devices such as key pad actuated door locks and security code protected computers. In addition to these advantages of security devices of the present invention, they can also be used to disable hardware or electrical/electronic devices and operating electromechanical locks and machinery.

The security device shown in Fig. 2 is substantially identical to that shown in Fig. 1 except that instead of the output device 6 being a radio frequency transmitter, it is an amplifier which feeds amplified signals from the timer 5 to an electrode 16, and instead of the receiver 11 being designed to detect radio frequency signals from a radio frequency transmitter, it responds to electrical signals passed to it via the body of the wearer of the transmitter 1.

The receiver 2 can then be made to function in one of two ways.

Firstly, it can be arranged to function by the wearer of the transmitter touching the electrode 17. Pulses from the timer 5

- 6 - are then fed from the electrode 16 via the wearer's body and into the receiver 2 via the electrode 17. This can be used in a similar manner to the security device described with reference to Fig. 1, and as with the security device of Fig. 1, breaking of the loop feeding code from the code generator 4 to the code entry device 3 will similarly result in the transmitter being deactivated until the loop is re-established and the appropriate code is entered into the code entry device.

Security devices described with reference to Figs. 1 and 2 can also be used in another manner. In particular, they can be used to maintain a protected device in an operating state by feeding coded signals into it from the transmitter 1 into the receiver 2. Whilst contact is maintained between the transmitter 1 and the receiver 2, for example by radio communication or by resistive transmission through the wearer's body, the protected device continues to function. However, breaking of the coded data connection between the transmitter 1 and the receiver 2 will result in the protected device being deactivated. This can happen either by breaking the connection between the code generator and the code entry device 3 via the loop 7, as has already been described, or by breaking the transmission path between the output device 6 and the receiver 11. In the latter case this might be effected by the protected device being physically removed from a person carrying it. It will also be appreciated that breaking the connection between the transmitter 1 and the receiver 2 could be used, for example, to activate the protected device, an example of this being to release a dye to stain bank notes in a snatch and run incident.

The transmitters 1 can be made physically small, for example of a similar size to that used for car key fobs. Entry of the necessary code into the code entry devices 3 can be effected in a similar manner to that used to program infra red or radio frequency actuated car keys.

Claims

1. A security device comprising a transmitter and a receiver for receiving and responding to signals from the transmitter, the transmitter including a code entry device for receiving a code to which the receiver responds, a code generator for generating code received from the code entry device, an output device for transmitting generated code to the receiver, a feedback loop for passing code from the code generator to the code entry device to maintain code generation by the code generator, and means whereby the feedback loop can be physically broken to cause the code generator to cease generating the code.

2. A security device according to claim 1, wherein the output device transmits coded infra-red signals.

3. A security device according to claim 1, wherein the output device transmits coded radio frequency signals.

4. A security device according to any of the preceding claims, wherein the feedback loop is maintained by a wire breaking the continuity of which serving to cause the code generator to cease generating the code.

5. A security device according to any of the preceding claims, wherein the receiver provides signals to a device protected thereby enabling the protected device to function whilst signals from the output device are received by the receiver.

6. A security device according to claim 5, wherein the protected device is reactivated following receipt of signals by the receiver from the output device.

7. A security device according to claim 5, wherein the protected device is inactivated following the receiver failing to receive signals from the output device.

- 8 -

8. A security device substantially as herein described with reference to the accompanying drawings.