Method and system to detect tampering using light detector

• US 20070152839A1
• Filed: 01/05/2006
• Published: 07/05/2007
• Est. Priority Date: 01/05/2006
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Tucker, James, Dalzell, William, Fleischman, Scott
• Granted Patent: US 7,388,486 B2
• Time in Patent Office: Days
• US Class Current: 340/686.100
• CPC Class Codes: G06F 11/3044 where the computing system component is the mechanical casing of the computing system
• CPC Class Codes: G06F 11/3058 Monitoring arrangements for monitoring environmental properties or parameters of the computing system or of the computing system component, e.g. monitoring of power, currents, temperature, humidity, position, vibrations thermal management in cooling arrangements of a computing system G06F1/206
• CPC Class Codes: G06F 11/3093 Configuration details thereof, e.g. installation, enabling, spatial arrangement of the probes
• CPC Class Codes: G06F 21/554 involving event detection and direct action
• CPC Class Codes: G06F 21/86 Secure or tamper-resistant housings
• CPC Class Codes: G08B 13/186 using light guides, e.g. optical fibres

Abstract

An optical anti-tamper system that includes at least one array of light sources located within a chassis and at least one array of photosensitive elements located within the chassis. The array of photosensitive elements are in communication with an alarm. The alarm is operable to transmit a tamper-event warning signal if an increased light level is detected by at least one array of photosensitive elements.

Claims

1. An optical anti-tamper system, the system comprising:

at least one array of light sources located within a chassis;

at least one array of photosensitive elements located within the chassis, the array of photosensitive elements in communication with an alarm, wherein the alarm is operable to transmit a tamper-event warning signal if an increased light level is detected by at least one array of photosensitive elements.

2. The system of claim 1, further comprising:

an opaque layer located between the array of light sources and the array of photosensitive elements, the opaque layer operable to prevent light emitted from the array of light sources from being incident on the array of photosensitive elements when in an unbroken state; and

a transparent layer located between the array of light sources and the array of photosensitive elements, the transparent layer operable to break the opaque layer when a protected component positioned adjacent to the transparent layer is touched during a tampering event so that the opaque layer is in a broken state, wherein the array of light sources and the array of photosensitive elements are positioned so that the light emitted from the array of light sources is incident on the array of photosensitive elements when the opaque layer is in the broken state.

3. The system of claim 2, wherein the transparent layer comprises a gel and abrasive particles dispersed within the gel.

4. The system of claim 2, wherein when light propagates from the array of light sources to the array of photosensitive elements the resulting increased light detected by the array of photosensitive elements initiates a tamper-event warning signal.

5. The system of claim 2, wherein an opaque-layer-break tampering event includes a relative movement between two or more components within the chassis, wherein the relative movement causes the transparent layer to break the opaque layer.

6. The system of claim 5, wherein at least one of the two or more components comprise an electronic circuit board.

7. The system of claim 1, wherein the chassis in a closed state is impenetrable to light, wherein a chassis-opening tampering event occurs when the chassis is open to an external environment and external ambient light reaches the array of photosensitive elements, and wherein the increased light level is detected by the one or more arrays of photosensitive elements.

8. The system of claim 1, wherein the array of light sources is selected from an array of light emitting diodes, an array of lasers, an array of vertical cavity light emitting diodes and combinations thereof, and wherein the array of photosensitive elements is selected from an array of photosensitive pixels, a charge-coupled device, an array of photo-detectors and combinations thereof.

9. A method of manufacture, the method comprising:

positioning at least one array of light sources within a chassis;

positioning at least one array of photosensitive elements within the chassis operable to receive light from at least one array of light sources;

positioning at least one opaque layer to prevent light from propagating from the array of light sources to any one of the arrays of photosensitive elements; and

connecting an alarm in communication with one or more photosensitive elements correlated to the array of photosensitive elements.

10. The method of claim 9, further comprising:

closing the chassis when the at least one array of light sources, the at least one array of photosensitive elements, and the at least one opaque layer are positioned; and

calibrating the at least one array of photosensitive elements for an ambient light level within a closed chassis.

11. An optical anti-tamper system, the system comprising:

means to break an opaque layer positioned over an array of light sources responsive to a touching of one or more components within a chassis;

means for detecting an increased light level at an array of photosensitive elements within the chassis responsive to the break; and

means for generating a tamper-event warning signal responsive to the detecting.

12. The optical anti-tamper system of claim 11, the system comprising:

means for damaging at least a portion of the component within the chassis responsive to generating the tamper-event warning signal, wherein the damaged portion of the component is made at least one of inoperable and irretrievable.

13. A method to detect a tampering event, the method comprising:

breaking an opaque layer, wherein the break is located between an array of light sources and one or more arrays of photosensitive elements within the chassis;

transmitting light from a portion of the array of light sources through the opaque layer responsive to breaking the opaque layer;

detecting an increase in a light level at the one or more array of photosensitive elements responsive to the transmitting light; and

generating a tamper-event warning signal responsive to the detecting.

14. The method of claim 13, further comprising:

damaging at least a portion of components within the chassis responsive to generating the tamper-event warning signal, wherein the damaged portion of the components is made at least one of inoperable and irretrievable.

15. The method of claim 14, further comprising:

transmitting the tamper-event warning signal responsive to generating the tamper-event warning signal.

16. The method of claim 13, further comprising:

transmitting the tamper-event warning signal responsive to generating the tamper-event warning signal.