WO1999005601A1

WO1999005601A1 - Security system

Info

Publication number: WO1999005601A1
Application number: PCT/AU1998/000572
Authority: WO
Inventors: James Edward Green
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-07-22
Filing date: 1998-07-20
Publication date: 1999-02-04
Anticipated expiration: 2000-01-22
Also published as: AUPO817697A0; AU690058B3

Abstract

A security system is disclosed for preventing unauthorised access to data or other information stored in or processed by electronic data processing means (11) enclosed within a housing (10), the security system including: detection means (37) for detecting access or attempted access to the electronic data processing means from without the housing, and destruction means (13, 12) for destroying the data or other information stored in or processed by theelectronic data processing means (11).

Description

"SECURITY SYSTEM"

Technical field

This invention relates to a security system. The invention has particular but not exclusive application to a security system for preventing unauthorised access to data or other information stored in or processed by electronic data processing systems.

As used herein the expression "electronic data processing system" has a broad meaning and includes any system in which data is processed electronically. Some examples of electronic data processing systems include mobile telephones, computers, EFTPOS facilities and secure access systems.

Background of Invention

The need to protect software against unauthorised access, particularly in security applications is well known. If unauthorised access can be gained to the control boards and programs of equipment processing the flow of data, the dataflow can be monitored by a data analyser and unauthorised third parties can obtain confidential information. Physical proximity to the chip processing or storing the data greatly facilitates this monitoring and analysis.

As an example, mobile phones include a chip which when activated establishes a legalising assignment or identification to an individual phone. A removable smart card then assigns a unique telephone number to the individual phone and when the legal assignment and the telephone number are associated upon use of the phone, billing procedures are initiated and directed to the owner of the phone. If unauthorised access to the interior of the phone casing is gained, the chip and phone software can be monitored and data flow and analysed whereby telephone account billings can be falsified.

Similarly in data transmitting devices with encryption facilities, access to the interior of the devices simplifies access to security codes embedded in an EEPROM chip for example, and allows monitoring of data flow and analysis of the "eavesdropped" data to enable decryption of the encrypted messages.

Known systems to prevent unauthorised access in such equipment provide switching means which are activated when the case containing the chip or software to be secured is opened. The switching means activates a mechanism to protect the chip or software.

Summary of Invention

The present invention aims to provide an alternative to known security systems for preventing unauthorised access to data or other information stored in or processed by electronic data processing systems.

This invention in one aspect resides broadly in a security system for preventing unauthorised access to data or other information stored in or processed by electronic data processing means enclosed within a housing, the security system including:- detection means for detecting access or attempted access to the electronic data processing means from without the housing, and destruction means for destroying the data or other information stored in or processed by the electronic data processing means.

It is preferred that the detection means are adapted to activate the destruction means to destroy the data or other information stored in or processed by the electronic data processing means upon detection by the detection means of access or attempted access to the electronic data processing means from without the housing. The detection means may take various forms and in one embodiment may be a normally open switch closed when the housing is opened. Alternatively the housing may be sealed with the electronic data processing means may be sealed within the housing and the interior of the housing pressurised to above atmospheric pressure with the detection means comprising a pressure sensitive switch.

In an alternative embodiment the detection means includes processor circuit means in the electronic data processing means, and housing circuit means in the housing. The processor circuit means and the housing circuit may constitute a reactance circuit and the reactance may be either a capacitive reactance or an inductive reactance.

In this arrangement the system includes :- oscillator means tuned to the reactance circuit for generating a fixed frequency; frequency detector means for detecting variation from the fixed frequency, and switching means responsive to detection of the frequency variation to apply a voltage to destroy the chip containing the data or other information stored in or processed by the electronic data processing means. In a preferred embodiment the destruction means includes a stand-alone power supply independent of the primary power supply to the electronic data processing means .

The arrangement may also include voltage detection means for detecting a predetermined minimum threshold voltage in the stand-alone power supply, the voltage detection means actuating the stand-alone power supply to destroy the data or other information stored in or processed by the electronic data processing means upon detection by the voltage detection means of the predetermined minimum threshold voltage. It is preferred that the system further includes warning means for warning that the voltage of the stand-alone power supply is approaching the predetermined minimum threshold voltage.

In another aspect this invention resides broadly in a method of preventing unauthorised access to data or other information stored in or processed by electronic data processing means enclosed within a housing, the method including:- detecting access or attempted access to the electronic data processing means from without the housing, and destroying the data or other information stored in or processed by the electronic data processing means in response to detection of the access or attempted access.

In a preferred embodiment the method includes :- locating processor circuit means in the electronic data processing means, and locating housing circuit means in the housing; wherein the processor circuit means and the housing means constitute detection means for detecting access or attempted access to the electronic data processing means from without the housing.

In a further aspect this invention resides broadly in a mobile telephone including :- a housing; electronic data processing means enclosed within the housing; detection means for detecting access or attempted access to the electronic data processing means from without the housing, and destruction means for destroying the data or other information stored in or processed by the electronic data processing means.

Description of Drawings In order that this invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention, wherein :-

FIG 1 is a schematic illustration of a housing containing a chip;

FIG 2 is a schematic illustration of a mobile telephone;

FIG 3 is a schematic circuit diagram of an arrangement to destroy the chip if the security of the housing is breached;

FIG 4 schematically illustrates a reactance coupling for detecting if the security of the housing is breached; FIG 5 is a schematic circuit diagram illustrating the operation of a security system in accordance with the invention which includes an inductive coupling, and

FIG 6 is a schematic circuit diagram illustrating the operation of a security system in accordance with the invention which includes a capacitive coupling and an independent internal power supply to destroy the chip.

Description of Preferred Embodiment of Invention

As can be seen in FIG 1, a housing 10 contains a chip 11 to which it is desired to prevent close physical access.

A practical example is a mobile telephone 14 illustrated in FIG 2 which has a housing 15, a battery power pack 16 covering a hatchway 17 providing access to internal componentry including chip 18.

As can be seen in FIG 3, an internal power-supply in the form of a long-life battery 13 is connectable through normally open switch 12 to chip 11. When switch 12 is enabled, voltage source 13 is connected across chip 11 and destroys it. Switch 12 is activated by detection means 37 which detect any breaching of housing 10. Consequently if an attempt is made to locate a monitor or data analyser physically close to chip 11, as for example by opening a hatchway, removing a cover or even drilling a hole to insert a micro-device, the breaching of housing 10 is detected by detection means 37, and power is applied from voltage source 13 to destroy chip 11.

It will thus be realised that the security system of the present invention preserves security by destroying any sensitive data before it can be accessed. It will be appreciated that the chip will be destroyed on all occasions when the integrity of housing 10 is breached. This means that the chip is destroyed even when authentic repair work is being carried out and the housing is opened legitimately.

This of course is no real disadvantage because the cost of the componentry being destroyed is not great, and it is relatively simply to reprogram new chips for the required purpose.

It will be appreciated that the chips to be protected may be completely sealed within an integral housing (not shown) and the housing pressurised to a pressure above or below atmospheric. A pressure sensitive switch (not shown) detects the variation in pressure if the housing is breached and closes the circuit to destroy the chip as described above.

Alternatively in a manner not shown, the housing can include two surfaces juxtaposed when the housing is closed and separated when the housing is opened. Juxtaposition of the surfaces has the effect of opening a normally closed electrical switch. If the juxtaposed surfaces become separated the switch closes and the circuit to a power supply is completed to destroy the chip.

Alternatively as seen in FIG 4, the juxtaposed surfaces 19 and 20 may each include a circuit component 21,22 such that the juxtaposed components constitute a reactance coupling circuit.

FIGS 5 and 6 respectively illustrate inductive and capacitive coupling of the juxtaposed surfaces to effect destruction of the chip when the reactance of the coupling circuit varies. Induction loops 23 and 24 (in FIG 5) and capacitor plates 29 and 30 (in FIG 6) are respectively positioned in juxtaposed surfaces of the housing hatch and the housing per se. In both instances oscillator 25 generates a fixed frequency in accordance with the reactance of coupling 23,24 or 29,30. Frequency detector 26 detects variation in the frequency from oscillator 25 generated by variation in the reactance of the coupling by breaching the housing by separating the normally juxtaposed surfaces. If frequency detector 26 detects a variation in the frequency, a normally open switch 27 is closed to connect independent voltage supply 28 across the chip to thereby destroy it. As best seen in FIG 6, a minimum threshold voltage detector 29 is connected across long-life battery 28 to detect when the voltage drops to a predetermined level.

At this level the detector closes normally open switch 28 as described above to destroy the chip. A warning signal can be generated by signal generating means (not shown) to give a warning as the voltage of power source 28 approaches the minimum threshold level.

In use, the so called "scorched earth" security of the present invention operates to ensure that the chips are destroyed irrespective of the circumstances under which the housing is opened or otherwise breached, ie whether authorised or unauthorised.

It will be appreciated that the security system of the present invention has a number of advantages over known security systems which are directed toward denying access to the chip rather that destroying the chip if access is obtained.

It will of course be realised that whilst the above has been given by way of an illustrative example of this invention, all such and other modifications and variations hereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad scope and ambit of this invention as is herein set forth.

Claims

1. A security system for preventing unauthorised access to data or other information stored in or processed by electronic data processing means enclosed within a housing, said security system including :- detection means for detecting access or attempted access to said electronic data processing means from without said housing, and destruction means for destroying the data or other information stored in or processed by the electronic data processing means.

2. A security system as claimed in claim 1, wherein said detection means are adapted to activate said destruction means to destroy the data or other information stored in or processed by the electronic data processing means upon detection by said detection means of access or attempted access to said electronic data processing means from without said housing.

3. A security system as claimed in claim 2 , wherein said detection means is a pressure sensitive switch.

4. A security system as claimed in claim 2 , wherein said detection means includes :- processor circuit means in said electronic data processing means, and housing circuit means in said housing.

5. A security system as claimed in claim 4, wherein said processor circuit means and said housing circuit constitute a reactance circuit.

6. A security system as claimed in claim 5, wherein said reactance is a capacitive reactance.

7. A security system as claimed in claim 5, wherein said reactance is an inductive reactance.

8. A security system as claimed in claim 5, and including:- oscillator means tuned to said reactance circuit for generating a fixed frequency; frequency detector means for detecting variation from said fixed frequency, and switching means responsive to detection of said frequency variation to apply a voltage to destroy the chip containing the data or other information stored in or processed by the electronic data processing means.

9. A security system as claimed in claim 1, wherein said destruction means includes a stand-alone power supply independent of the primary power supply to the electronic data processing means.

10. A security system as claimed in claim 9, and including voltage detection means for detecting a predetermined minimum threshold voltage in said standalone power supply, said voltage detection means actuating said stand-alone power supply to destroy the data or other information stored in or processed by the electronic data processing means upon detection by said voltage detection means of said predetermined minimum threshold voltage.

11. A security system as claimed in claim 10, and including warning means for warning that the voltage of said stand-alone power supply is approaching said predetermined minimum threshold voltage.

12. A method of preventing unauthorised access to data or other information stored in or processed by electronic data processing means enclosed within a housing, said method including:- detecting access or attempted access to said electronic data processing means from without said housing, and destroying the data or other information stored in or processed by the electronic data processing means in response to detection of said access or attempted access.

13. A method of preventing unauthorised access as claimed in claim 12, said method including:- locating processor circuit means in said electronic data processing means, and locating housing circuit means in said housing; said processor circuit means and said housing means constituting detection means for detecting access or attempted access to said electronic data processing means from without said housing.

14. A mobile telephone including:- a housing; electronic data processing means enclosed within said housing; detection means for detecting access or attempted access to said electronic data processing means from without said housing, and destruction means for destroying the data or other information stored in or processed by the electronic data processing means.