AU694246B2 - Electronic security apparatus and method - Google Patents

Description

AUSTALIARegulation 3 Patents Act 1990

ORIGINAL

I COMPLETE SPECIFICATION STANDARD PATENT InvntonTitle:......... ELECTRONIC,..SECUR.TY...APPRA.TS... I The following statement Is a full description of this invention, Including the best V method of performing it known to me:- II I I_ 1_1~ -1- This invention relates to electronic security equipment using coded transmissions generated by an encoder coupled with a transmission device and a decoder coupled with a receiving device, transmission of these S coded signals can be achieved by using radio frequency, infra-red, or electro-mechanical link means such as via cables. One possible application is by remote control operation in an electronic security method for preventing unauthorized access, locking and unlocking using a changing data code radio-frequency remote-control coded signal.

Prior data code equipment and devices used to communicate data codes between a transmitter and a receiver (whether by radio frequency or electro-mechan- 4C !b ical physical link means such as cables) contain a fixed code which is used during every transmission and no matter what device it is incorporated into or what method is used such as for example a radio-frequency rf remote control security system arming/disarming a 20 vehicle, opening a garage door and so forth it can be detected by unauthorized persons, using electronic detection/analysing/recording equipment. Retransmitting duplicated/recorded or learned code in the same manner will allow access to one's property or enable use of the 2$ learned code to intercept communications in a link, Any fixed coded signal transmission is no longer secure.

One object of this invention is to provide electronic security apparatus which will address the problem of unauthorized access.

-2- Another and related object of this invention i to provide an electronic security method which will address the foregoing problem of unauthorized access.

According to the invention there is provided r electronic security apparatus for preventing unauthorized access to a security device, communications equipment or other equipment, the apparatus compries an encoding device coupled with a transmitter and a decoding device coupled with a receiver, a data-coded [O signal being generated between the transmitter and the receiver, part of the coded signal is fixed but the remainder i's continuously and automatically changing, and means for maintaining synchronization between the 4* transmitter and the receiver, So.'.t Preferably, the means for maintaining synchronization between transmitter and receiver is a timer clock chip in the transmitter and a timer clock 4 4 0 chip in the receiver both timer clock chips being 9. 4 identical and being adapted to operate on the same o 4.

V

'20 oscillation frequency.

Preferably, a programmable microcontroller *e chip is in the encoder within the transmitter and an identical programmable microcontroller chip is in the decoder within the receiver, More particularly, both the transmitter and the receiver are each factory-programmed during manufacture so as to each have its own re-set mode.

According to the invention there is alco provided an electronic security method for preventing unauthorized access to a security device, communioationo equipment or other equipment, and wherein the method comprises generating a data coded signal between an encoding devioe coupled with a transmitter and a decoding device coupled with a receiver, fixing part of the coded signal and continuously and automatically changing 'the remainder of the data coded signal with reference -to time and maintaining synchronization of both the transmitter and the receiver.

K[ to Preferably, the method according to the invention further comprises programming speciallydesigned software into a microcontroller unit contained .'within the encoding device and into a microcontroller unit contained within the decoding device, while maintaining synchronization of the changing signal code part 4 "i of both the transmitter and the receiver by operation of a timer clock chip in both the transmitter and the t' receiver.

*4 49 9 $44 j Preferably, each of said timer clock chips is identinal and operates at the same internal oscillation frequency which determines rate of change of the code.

More preferably, the method according to the invention further comprises using identical timer clock chips and identical microcontrller units in both the 2G- encoding and decoding devices to continuously and automatically change the non-fixed part of the coded signal while maintaining synchronization between the encoding device and thus the transmitter and the decoding device and thus the receiver.

A non-limiting example of a preferred embodiment or practical arrangement of the electronic security apparatus and method of the invention will now be described in detail with reference to the accompany-" ing diagrammatic drawings, in which: Figure 1 is a block diagram of an arrangement of -the transmitter of the electronic security apparatus or, syoten used in tho method according to the invention.

Figure 2 is a block diagram of an arrangement (D of the receiver of the electronic security apparatus or ,system used in the method according to the invention, Figure 3 is a block diagram of apparatus e1 incorporating a transmitter and a receiver with alternative types uf operational links for' use in the elect- IS** ronic security method according to the invention.

Referring to the drawings, the method of the invention comprises generating a data coded signal between an encoder coupled with a trans- mitter and a decoder coupled with a receiver in a set and, in this example, a battery-operated, remote- control, electronic security apparatus or a syatem specifically designed for use with vehicles (but may have application for' protecting other equipment such as permanent installations operating from a mains or other source of emf for example a garage door or doors) to prevent unauthorized access thereto and which comprises a portable and preferably hand-held, cordless, rf radiofrequency, coded signal transmitter 10 and a rf radiofrequency, coded signal receiver 11, there being a codedi with a fixed code part and a changing code part between (in this example) a transmitter and a receiver and wherein part of the changing code part of the coded signal is constantly and automatically changing. A part V of the code i-s constantly and automatically changed on a time baeu by means of an associated operatively linked timer chip clock contained within each transmitter and receiver of the set. The apparatus or system incorporates two identical timer chip clocks 12, 13, operating C) at the same frequency and also incorporates two identical programmable micro-controller chips 14 and 15. One timer clock chip 12 and one micracontroller chip 14 are in the transmitter 10 and another timer clock chip 13 a I, and microcontr-oller chip 15 are in the receiver 11. The timer clock chips 12, 13, change the transmitted code within a regular time period and maintain synchronization by operating at the same internal oscillation 4u frequency which is factory adjustable by interchanging crystals of different values. A suitable micro-controlla aJ er chip for use in this invention is TIC-16C54 of Micro- Chip Technology and a suitable timer chip is DS 1202 of Dallas.

a The receiver component of the device is incorporated within or installed within a vehicle 16 or 2 whatever equipment it is securing such as garage door, Once power is connected to the hand-held transmitter and to the receiver via an in-unit battery, or other source of D.C. voltage, the timer clock chipi 12, 13, are synchronized in time by a reset mode as the clocks are at random and probably different time so reset initialization must take place. Each transmitter and receiver is manufactured and supplied with its own reset mode which is programmed in at the time of r manufacture. Once the clocks 12, 13, are synchronized, the apparatus and any sys3temn incorporating it are ready for normal uae. The operator presees a switch an the hand-held transmitter 10, transmitting a part fixed data-coded siAgnal and a part changing data-coded signal (0 which i:s retrieved from a loolt-up table corresponding to the time of transmission. The apparatus or system u,;e,.s the timer clock chips 12, 1:3 to change part of the coded signal at pre-set time intervals. The receiver operation is such that if the firNed part of the data I coded signal is correct, the apparaturt continues and 00 compares the changing part of the coded signal which, if the clocks are aligned, the zignal will be the same, :depending on the time of tran.,mission. If the changing 0:0::.part of the signal is correct, the receiver then 000 0 acivts or de-activates whatever equipment it is controlling. If a wrong coded signal Js detected by the xeceiver, it does not respond, In operation, the device uses a fixed part of code) coded signal and a changing (remainder of Qode) 2 coded signal which changes constantly with time in a set order on both -the transmitter 10 and the receiver 11.

In other words the device uses a data coded signal part of which ic; fixed and part of which io, continuou 31y and automatically changing at a pre-set time interval on both the -transmitter 10 *nd the receiver 11. in synchiron- The invention is applicable to anything which I requires remote-control, security operation such as for if example vehicle anti-theft devices, roller doors, afe, keyless electronic door lock,,: and the like.

Advantages of the invention are that the clocks of the transmitter and receiver units of the device or sycstem of the invention are not set to real f time which makeG unauthorized acceSS difficult if not impossible. Furthermore, the reset function can only be invoked if continuous valid data is received hence making it highly unlikely for a learned code to be u~sed.

*a Although the device of the invention has been described in the example as utilizing separate microprocessor and timer chips, it sThould be understood that single chip or there could be other chips- in addition .4 to the two described.

The electronic security device of the invention is adapted to be incorporated into a system which additionally comprises a vehicle or any other equipment to be abled or disabled such as a garage door.

The concept of the invention of a coded 215 signal with a fixed part and a changing part could be incorporated into apparatus using electromechanical or physical data link such as cables, including fibre-optic date communication cables or infra red system- instead of a radio-frequency link and between any transmitter i 4 and r-~ceiVer using a coded signal.

II

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Claims (10)

1. 6. The apparatus according to any one of claims 2 to 5 wherein each microcontroller chip has its own re-set mode programmed in at the time of manufacture,
2. 7. The apparatus according to any preceding claim and which is adapted to be incorporated into a system which additionally comprises a vehicle or any other equipment to be abled or disabled such as a garage door,
3. 8. The apparatus according to claim 7 wherein the the transmitter is portable and hand held and operates on radio frequency signals and the receiver is fixed within a vehicle and operates on the same said I radio-frequency signals.
4. 9. The apparatus according to claim 7 wherein the I'transmitter is portable and hand-held and operates .n radio-frequency signals and the receiver is fixed within 4 a garage and operates on the same radio-frequency signals as that of the transmitter to open and close a garage door or doors.
5. 10. An electronic security method for preventing unauthorized access to a security device, communications equipment or other equipment, and wherein the method comprises generating a coded signal between an encoder device coupled with a transmitter and a decoding device coupled with a receiver, fixing a part of the coded signal and continuously and automatically changing the remainder of the signal with reference to time whilst maintaining synchronization of both the transmitter and the receiver. r -r i I I'mILU JUHN KRIZAY and SAM LAZARAKIS By Our Patent AttorneyJOHN L.DAVIES&CO. 15th August, 1995 (Signature) (Dat (Date) CO 2.878 1 17 I, -11-
6. 11. The method according to claim 10 which further comprises programming specially-designed software into a microcontroller chip contained within the encoding device and into a microcontroller chip contained within the decoding device, while maintaining synchronization of the changing signal code by operating a timer chip clock in both the transmitter and the receiver, each of said clocks being identical and operating at the same internal oscillation frequency which determines rate of change of the code.
7. 12. The method according to claim 10 or 11 which further comprises using identical timer chip clocks and identical microcontroller chips in both the encoding and decoding devices to continuously and automatically change the non-fixed part of the coded signal while maintaining synchronization between the encoding device and thus the transmitter and the *t9a decoding device and thus the receiver.
8. 13. The method according to any one of claims *I to 12, wherein after electric power is connected to the transmitter and to the receiver via an in-unit battery or other source of DC voltage, reset initialization is effected of the timer clock chips of both the transmit- ter and the receiver respectively to synchronize the chips in time from any random and different time mode, by a reset mode.
9. 14. The method according to any one of claims to 13 whereby when an operator of the apparatus of any one of claims 1 to 9 presses a switch on the L__ i Il~CI I- L- dr visio r/.mpauiso wnere details for PCT, convention priority, microorganism deposit, additional or divisional appIcation, are required. CO 2 87 8 1 1 7 AUG -12- hand-held transmitter transmitting a part fixed data-coded signal and changes the remainder of the data-coded signal which is retrieved from a look-up table corresponding to the time of transmission, the apparatus uses the timer clock chips to change part of ii coded signal at pre-set time intervals whereby if the fixed part of the data-coded signal from the transmitter i is detected and identified by the receiver as being i correct, the receiver then compares the changing part of the coded signal which,if the clocks are aligned, will be identical on both the transmitter and the receiver depending on the time of transmission, if the changing S' part of the signal is correct the receiver then activates or deactivates whatever equipment it is i controlling and whereupon, if a wrong signal is detected Sby the receiver it does not respond. Electronic security apparatus substantially as hereinbefore described with reference to the accompanying drawings.
10. 16. A method of electronic security substantially ttte as hereinbefore described with reference to the accomp- anying drawings. it tt I t 4 Dated this 15th day of August 1995 JOHN MARIO KRIZAY and SAM LAZARAKIS By Our Patent Attorney JOHN L.DAVIES CO. i I ABSTRACT An electronic security apparatus and method prevents unauthorized access to a security device, communications equipment or other equipment a data coded signal is generated between an encoding device coupled with a transmitter (10) and a decoding device coupled with a receiver part of the coded signal is fixed but the remainder is continuously and automatically changing; synchronization is maintained between transmitter and receiver (11) by an identical timer chip clock (12,13) in each which operates on the same oscillation frequency; specially designed computer software is used to program an identical microcontroller chip (14,15) respectively within the transmitter (10) and the r 9 9 '"receiver (11). 9 9