LINDORF, Justin (72 Combridge Drv, Beremboke, Victoria 3342, AU)
AVENARD, Jean-Yves (54 Warrigal Road, Surrey Hills, Victoria 3127, AU)
BROOKFIELD, Ivan John (70 St Georges Road, Elsternwick, Victoria 3185, AU)
BRYDON, Mark (10 Carina Cl, Wantirna Sth, Vic 3152, AU)
TAYLOR, Barry John (70 Georges Rd, Elsternwick, Victoria 3185, AU)
HARCOURT, Jefferson (12/63 Ormond Esplanade, Elwood, Victoria 3184, AU)
LINDORF, Justin (72 Combridge Drv, Beremboke, Victoria 3342, AU)
AVENARD, Jean-Yves (54 Warrigal Road, Surrey Hills, Victoria 3127, AU)
BROOKFIELD, Ivan John (70 St Georges Road, Elsternwick, Victoria 3185, AU)
BRYDON, Mark (10 Carina Cl, Wantirna Sth, Vic 3152, AU)
TAYLOR, Barry John (70 Georges Rd, Elsternwick, Victoria 3185, AU)
CLAIMS:
1. Apparatus for securing connections between electronic components in order to detect tampering of the connections or components, the apparatus comprising: a layered structure whereby a first layer of electronic components is connected to a second layer of electronic components through a connection medium; such that each connection between the layers of electronic components remains within the footprint defined by each layer and extends through the connection medium thereby substantially preventing undetected tampering of the connections or components.
2. Apparatus according to claim 1 wherein connections between electronic components in separate layers that are adjacent the perimeter of any of the footprints defined by each layer are protected by guard traces connected to the electronic components that enable tamper detection of the connections adjacent the perimeter.
3. Apparatus according to claim 1 or claim 2 wherein any one or more of the layers is connected to tamper detection means that provides a signal on detecting tampering to the connections or components.
4. Apparatus according to claim 3 whereupon receipt of the signal circuitry is enabled to undertake any one or more of erasing any stored data within the electronic components, disabling any of the electronic components or activate an alarm.
5. Apparatus according to any one of the previous claims wherein the components are packaged in bail grid arrays.
6. Apparatus according to claim 5 wherein the components are packaged in fine pitched ball grid arrays.
7. Apparatus according to any one of the previous claims wherein the connection medium is a printed circuit board.
8. Apparatus according to claim 7 wherein the printed circuit board has a first side connected to electronic components in the first layer and a second side connected to electronic components in the second layer.
9. Apparatus according to any one of the previous claims comprising one or more further layers having a further connection medium between each layer.
10. A system of enabling detection of tampering to apparatus comprising: a flexible printed circuit that substantially surrounds the apparatus; the flexible printed circuit containing inductance means; wherein a change in at least one parameter of the inductance means indicates movement of the flexible printed circuit and possible tampering to the apparatus.
11. A system according to claim 10 wherein the inductance means comprises a series of inductive traces formed of inductors placed side by side across the flexible printed circuit.
12. A system according to claim 11 wherein the inductors form a combination of mutually coupled and non-coupled inductors.
13. A system according to any one of claims 10 to 12 wherein the at least one parameter is the impedance of the inductors.
14. A system according to claim 13 connected to an impedance measuring circuit for measuring any change in the impedance of the inductors, the impedance measuring circuit providing a signal where there is a change in impedance of any one of the inductors.
15. A system according to claim 14 wherein the impedance measuring circuit is connected to an intrusion response circuit such that on receipt of the signal by the intrusion response circuit, the intrusion response circuit initiates the activation of an alarm or erasing of data stored in the apparatus.
16. A system according to claim 15 wherein the apparatus includes the impedance measuring circuit and the intrusion response circuit.
17. Apparatus for detecting tampering to a device housing, the apparatus comprising: an optical source for emitting light; an optical detector for receiving the emitted light from the optical source; wherein the emitted light is reflected from the housing in travelling from the optical source to the optical detector, such that any disturbance in the path of the emitted light from the optical source to the optical detector indicates tampering to the housing and possibly to the device located within the housing.
18. Apparatus according to claim 17 wherein the optical source emits the light in pulses at a set frequency or a series of differing frequencies to which the optical detector is tuned to receive.
19. Apparatus according to claim 17 or claim 18 wherein the emitted light is reflected from an internal surface of a cover to the housing.
20. Apparatus according to claim 19 such that any opening or removal of the cover disturbs the path of the emitted light thereby detecting tampering.
21. Apparatus according to any one of claims 17 to 20 connected to a circuit that is responsive to the tamper detection that triggers an alarm or otherwise enables data stored in the device to be erased. |
Tamper Detection Arrangement and System
Field of the Invention
TMs invention relates to an arrangement and system for detection of tampering of a device or interconnected devices.
Background to the Invention
The increasing use of electronic devices in fields that require security, such as e- communications, identification and monitoring requires that the devices be secure. Often the internal security of such devices is provided by large and bulky housings, internal shielding and epoxying of critical components. All of these methods increase the cost, weight and size of the electronic device where it is often intended to be lightweight, small and cost effective. Other internal security measures of electronic devices are provide by security shields that monitor either a break in a conductor or changes in the resistance of conductors. Whilst most of these methods provide a certain level of protection, they are relatively easy to bypass. This may be done by short circuiting contacts in the case of systems that detect breaks in conductors and the application of the series resistances, where the resistance of conductors is monitored, thus bypassing the intrusion detection mechanism of the device. In order to provide additional security measures, it is desirable to detect if a part or all of a housing surrounding a device, such as an electronic device, has been removed. A common method has been to use trip switches, however these are often able to be bypassed once the location of the trip switches is known. Another common method uses a light detector, however this form of tamper detection can be bypassed by either opening the product in the dark, or covering the light sensor with an opaque material.
The present invention seeks to overcome one or more of the above disadvantages by providing a method and system for tamper detection that provides security to devices, when such devices are accessed by unauthorised persons, whereby sensitive data stored in such devices, is not able to be retrieved by such unauthorised persons.
Summary of the Invention
According to a first aspect of the invention, there is provided apparatus for securing connections between electronic components in order to detect tampering of the connections or components, the apparatus comprising:
a layered structure whereby a first layer of electronic components is connected to a second layer of electronic components through a connection medium; such that each connection between the layers of electronic components remains within the footprint defined by each layer and extends through the connection medium thereby substantially preventing undetected tampering of the connections or components.
Connections between electronic components in separate layers that are adjacent the perimeter of any of the footprints defined by each layer may be protected by protection means preferably in the form of guard traces connected to the electronic components that enable tamper detection of the connections adjacent the perimeter.
Any one of the layers of electronic components may be connected to a response circuit that performs a designated function, upon detection of such tampering by a tamper detection circuit. Upon receipt of a signal from the tamper detection circuit, the response circuit can perform the designated function, which may be any one of disabling any of the electronic components, erasing any confidential data within the apparatus, such as stored in memory on one of the layers of electronic components, or stored in a device that incorporated the apparatus or initiating an alarm.
Preferably the electronic components are integrated circuits including processors and memories. The electronic components may be packaged in suitable packaging means such as ball grid arrays (BGA) or fine pitched ball grid arrays (FPBGA).
Preferably the connection medium is a printed circuit board, with a first side connected to electronic components in the first layer and a second side connected to electronic components in the second layer.
According to a second aspect of the invention, there is provided a system of enabling detection of tampering to an apparatus comprising: a flexible printed circuit that substantially surrounds the apparatus; the flexible printed circuit containing inductance means; wherein a change in at least one parameter of the inductance means indicates movement of the flexible printed circuit and possible tampering to the apparatus. The inductance means may comprise a series of inductive traces comprising inductors placed side by side across the printed circuit. The inductors may be a combination of mutually coupled and non-coupled inductors.
The at least one parameter may be the impedance of an inductor. Other parameters may include the voltage or current of an inductor. The system may further comprise or be connected to an impedance measuring circuit for measuring a change in the impedance of one or more of the inductors.
An intrusion response circuit may be linked to the system or to the impedance measuring circuit which, in response to receiving a signal from the impedance measuring circuit indicative of a change in the impedance of one or. more of the inductors, may send a signal to activate an alarm or erase confidential or sensitive data, which may be stored in memory forming part of the apparatus or in a device which includes the apparatus.
The apparatus requiring protection may be mounted to a printed circuit board. The apparatus may include the impedance measuring circuit and intrusion response circuit. According to a third aspect of the invention there is provided apparatus for detecting tampering to a device housing, the apparatus comprising: an optical source for emitting light; an optical detector for receiving the emitted light from the optical source; wherein the emitted light is reflected from the housing in travelling from the optical source to the optical detector, such that any disturbance in the path of the emitted light from the optical source to the optical detector indicates tampering to the housing and possibly to the device located within the housing.
Thus, if the signal path is broken, such that the detector does not receive the emitted light, whereby either the housing is removed or opened or either the optical source or optical detector is covered, then this provides an indication that the device has been tampered with.
The emitted light may be reflected from an internal surface of a cover to the housing.
On the non-detection of the light from the optical source, a signal may be transmitted from the optical detector to a circuit that enables an alarm or otherwise erases confidential or sensitive data that may be stored in memory forming part of the device requiring protection.
The emitted light may be periodical at a set frequency, to which the detector is tuned, or may be random, again to which the detector is tuned. This may include light emitted at a series of differing frequencies.
Brief Description of the Drawings
The invention will hereinafter be described in preferred embodiments, by way of example only, with reference to the drawings wherein:
Figure 1 is a perspective view of a layered structure of device components preventing undetected tampering of connections between the device components according to a first embodiment of the invention;
Figure 2 is a perspective view of a flexible printed circuit which provides detection of tampering according to a further embodiment of the invention;
Figure 3 is a plan view of the flexible printed circuit of Figure 2;
Figure 4 is a basic block diagram of circuitry used to initiate a response to tampering of the circuit of Figure 2; and
Figure 5 is a perspective view of a system that provides an indication of tampering to a device according to yet another embodiment of the invention.
Detailed Description of the Preferred Embodiments
Referring to Figure 1, there is shown a layered structure 10 of two electronic components being connected through an intermediate medium such as a printed circuit board. The medium may be in the form of any suitable component or material that allows electrical connections to be made between the two electronic components. Specifically, there is shown a first layer 12 comprising a first electronic component and a second layer 14 comprising a second electronic component. The first layer 12 and the second layer 14 have various connections between the two layers made through an intervening layer or connection medium 16, which is preferably a printed circuit board. The invention is not limited to connecting securely two layers of electronic components but may incorporate the interconnection of more than two such layers of electronic components with intervening connection mediums of printed circuit boards.
Such an arrangement allows the connection of many different types of electronic components, such as integrated circuits that are packaged in ball grid arrays (BGA), or fine pitched ball grid arrays (FPBGA). As can be seen on the top surface of the second layer 14, the packaging is arranged in such grid arrays 18. The invention is not limited specifically to integrated circuits making up the electronic components.
Thus, the first layer 12 comprising the first integrated circuit is connected to the top side of the connection medium 16, while the second layer 14 of a second integrated circuit is connected to a lower side of the connection medium 16. The connections to be secured between the integrated circuits on layers 12 and 14 remain within the footprint of each integrated circuit array or layer. Connections that are routed near the extremities of the footprints can be protected by guard traces (not shown) which, when connected to electronic components such as integrated circuits in layers 12 and 14, can enable detection of tampering or intrusion thereto.
Therefore, the invention substantially prevents access to the connections between each of the electronic components defined by layers 12 and 14 from unauthorised tampering and tapping.
Another example of electronic components that may be used include a microprocessor and a memory which is accessed by the microprocessor. The printed circuit board defined by medium 16 may be multi-layered with blind and buried vias. The integrated circuits defined by layers 12 and 14 are mounted to the medium 16 by a manufacturing process such as surface mount reflow. Other suitable manufacturing processes may be used. Specific connections between the integrated circuits defined by layers 12 and 14 that require protection against tampering and tapping can include various address lines, control lines and data buses. Each of the layers of electronic components are aligned directly with each other on either side of the printed circuit board 16.
Should tampering or tapping be detected, by a suitable tamper detection circuit that may be part of the integrated circuits, dedicated circuitry may be instructed to delete or erase sensitive data, especially where that data is stored in a memory forming part or all of any one of the integrated circuits. In this manner, any sensitive data will not be disclosed to the unauthorised person who has tampered with the device. , The dedicated circuitry may also undertake to disable any of the electronic components or integrated circuits in the layers 12 and 14 or initiate an alarm. Alternatively, the layered structure may be linked to a portable electronic wireless device, or other type of device, that has confidential data stored thereon, such as bank keys. When the tamper detection circuit detects tampering to the layered structure, the dedicated, circuitry may in response erase all confidential data that is stored in the wireless device, so as to prevent access to that data by the unauthorised person. In a further embodiment and with reference to Figures 2 to 4, there is shown, a flexible circuit which is designed to surround and cover an area or product requiring protection from tampering. The product or area to be protected and the flexible circuit are generally located inside an outer casing of a particular device. For example, the area to be protected from intrusion can contain, but is not limited to, electronic circuitry mounted on a rigid printed circuit board 22.
The flexible circuit, which is in the form of a shield 20 contains inductive traces around its whole periphery, which are made up of mutually coupled and non-coupled inductances. The inductive traces are indicated and seen more clearly at 30 in Figure 3.
A further printed circuit board 24 having circuitry mounted thereon is shown in Figure 2 surrounded by a flexible circuit 26 containing inductive traces, and mounted on a top face of the board 22.
With reference to Figure 4 an impedance measurement circuit 40 is linked to the series of mutually coupled and non-coupled inductances that make up the inductive traces 30. The impedance measurement circuit 40 is also linked to an intrusion response circuit 42. Thus, the impedance as well as other parameters of the inductive traces on the flexible printed circuit 20, are monitored for any change. Any intrusion or tampering with the inductive shield or flexible printed circuit 20 towards the protected area of the device will change the impedance of the inductances, This change in impedance is detected by the impedance measurement circuit 40, which will then signal to the intrusion response circuit 42 that such a change has happened. The circuit 42 is then able to send a signal to raise an alarm or otherwise erase the sensitive data which may be stored in a memory or other parts of the device as well as the area to be protected. For example, the area to be protected, which is wrapped with the flexible printed circuit 20 may form a small part of a large device, such as a wireless telecommunications device which contains sensitive data such as banking keys or personal identification data. These can be erased by specific instruction from the response circuit 42. This thereby impedes an unauthorised intruder from access to such data. The invention is applicable to any equipment that needs protection and is not limited to electronic devices such as mobile or wireless devices. Other circuitry may be included in the protection area, such as keyboards, communications and computing circuits. The response circuit 42 may initiate the disabling of any part of the device.
As mentioned previously, the non-coupled and mutually coupled inductors can be realised by traces on the flexible circuit 20, however any other suitable material or arrangement may be used that can adequately have a series of inductors stored or impressed thereon. The flexibility of a flexible printed circuit 20, aids security in that as its positioning within the product is not precisely controlled, it makes it difficult for a would-be intruder to predict the exact location of the traces in order to disable such traces.
The area to be protected may be in the form of a printed circuit board that either encloses or has attached thereto various electronic components that needs to be protected from tampering. This is shown as 22 in Figure 2.
This particular embodiment replaces conventional conductors with non-coupled and mutually coupled inductors. The impedance of the inductors is monitored for change caused by intrusion through the protective shield or cover. The level of
difficulty of bypassing this mechanism is significantly increased as the bypassing of inductors is more difficult than bypassing open/short resistance detection systems. Furthermore, if a method for bypassing one inductor is realised, the inductors mutual inductance with other inductors in the system can be maintained, which can also be measured by the impedance measurement circuit 40. This combines to raise the complexity of defeating the security system than previously disclosed.
In yet a further embodiment of the invention, reference is drawn to Figure 5 in which is shown apparatus that provides detection of tampering or intrusion to equipment or electronic componentry by removal or movement of a cover. The cover or Hd is shown at 50 (partially broken away to show portions underneath the cover) which partially or fully covers an optical source 52, and has an internal surface that allows reflection of the light emitted from the optical source 52 to be received by an optical detector 54. Normally, when the cover 50 is intact, the optical detector 54 is kept in darkness except when the optical emitter 52 flashes periodically. Generally, the optical emitter emits a sequence of light pulses at varying frequencies to which the detector 54 is tuned.
The apparatus may incorporate or be linked to an intrusion response circuit similar to that described in relation to Figure 4.
Thus, if the cover 50 is removed by an intruder in a lit area, the intrusion response circuitry will be activated to perform functions, including raising an alarm or erasing sensitive data that might be stored within the device such as a memory. The optical emitter 52 flashes periodically or randomly with the emitted light reflected back to the optical detector 54 by the inside of the cover 50. This will also stop a would-be intruder opening the cover in light of a similar frequency to that emitted by the optical emitter 52 as the detector 54 still requires the light from emitter 52 to be reflected off the cover 50 and also at a particular frequency or series of frequencies.
The whole process forms a closed loop feedback mechanism which make it increasingly difficult to bypass the tamper detection system. If the cover 50 is opened in the dark, or if the optical detector 54 or optical source 52 are covered by a would-be intruder, the light from the optical source 52 will not be received by the optical detector 54 and therefore the intrusion response circuitry may be invoked to take a required action as mentioned previously. The housing may be made from plastic and is opaque in order to allow reflections to be received at the detector 54.
It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly
described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.