Multi-GHz guard sensor for detecting physical or electromagnetic intrusions of a guarded region

Patent metadata

Field	Value
Publication number	US-10938841-B2
Application number	US-201816166668-A
Country	US
Kind code	B2
Filing date	Oct 22, 2018
Priority date	Nov 2, 2017
Publication date	Mar 2, 2021
Grant date	Mar 2, 2021

Abstract

A guard sensor injects a multi-GHz (multi giga-bit) guard signal along a guard signal transmission path above an observable knee in the amplitude response of the path to define a guarded region and to detect physical or electromagnetic intrusions of that guarded region. At frequencies above the knee, the signal transmission path exhibits increasingly non-linear and even chaotic behavior that improves the overall sensitivity of the sensor and its ability to detect slight changes in the distributed transmission parameters that characterize circuit devices, signal paths and signals. The guarded region may be used to protect a combination of circuit devices, physical connections, interfaces, high and low frequency signal transmission paths and signals.

First claim

We claim:

1. A guard sensor for protecting one or more objects in a guarded region, comprising:
a processor;
one or more guard signal transmission paths defining the guarded region and configured to provide both an electromagnetic (EM) and physical barrier to intrusion of the guarded region, said one or more guard signal transmission paths characterized by an amplitude response with a knee frequency above which the paths exhibit non-linear behavior;
a transmitter configured to transmit one or more guard signals over the one or more guard signal transmission paths, said guard signals transmitted at frequencies Y above the knee frequency and at least 4 GHz;
a receiver configured to receive components of one or more received guard signals from the one or more guard signal transmission paths;

and
a memory, wherein the memory has stored thereon instructions that, when executed by the processor, cause the processor to:
generate and transmit the one or more guard signals over the one or more guard signal transmission paths;
measure the components of the received guard signals; and
compare the one or more components of the received guard signals to one or more previously received guard signals to detect changes in physically distributed transmission parameters of the one or more guard signal transmission paths or one or more guard signals at frequencies above the knee frequency and at least 4 GHz as a proxy for EM and physical intrusions on the guarded region.

2. The guard sensor of claim 1 , further comprising circuitry including first and second circuit devices connected by the one or more guard signal transmission paths that carry the one or more guard signals and one or more target signals, wherein at least a portion said one or more guard signal transmission paths and the one or more target signals constitute objects that lie within the guarded region.

3. The guard sensor of claim 2 , wherein the knee frequency is at least 4 GHz.

4. The guard sensor of claim 1 , further comprising circuitry including first and second circuit devices connected by one or more target signal transmission paths configured to carry one or more target signals at frequencies X where a ratio of Y/X is at least 5, wherein at least a portion said one or more target signal transmission paths and the one or more target signals constitute objects that lie within the guarded region.

5. The guard sensor of claim 4 , wherein X is less than 1 GHz and the knee frequency is at least 4 GHz.

6. The guard sensor of claim 4 , further comprising a multi-layer printed circuit board (PCB), wherein the one or more target signal transmission paths comprise single-ended traces, wherein the one or more guard signal transmission paths comprise differential transmission lines.

7. The guard sensor of claim 6 , wherein the multi-layer PCB comprises first and second power planes positioned between different layers of the PCB, wherein at least a portion of one of the single-ended traces is routed through a layer between the first and second power planes, wherein at least a portion of one of the differential transmission lines is routed above and below the first and second power planes to define the guarded region that encompasses the portion of the single-ended trace between the first and second power planes.

8. The guard sensor of claim 4 , wherein the circuitry further includes one or more target signal transmission paths configured to carry target signals at frequencies Z of at least 4 GHz where a ratio of Z/X is at least 5 between said first and second circuit devices, wherein the memory has stored thereon instructions that, when executed by the processor, cause the process to:
periodically measure physical characteristic data of the circuitry, operational data of the circuitry, and environmental data related to at least the one or more target signal transmission paths and target signals;
periodically capture the measured data;
generate a dynamic fingerprint based on an aggregation of a portion of the captured data, wherein the dynamic fingerprint is a compound data structure encapsulating the aggregated data;
associate metadata with the dynamic fingerprint;
periodically update the dynamic fingerprint according to successive sets of the captured data; and
compare the updated dynamic fingerprint to a previous dynamic fingerprint, to detect the changes in the dynamic fingerprint as a proxy for EM and physical intrusions on the circuitry.

9. The guard sensor of claim 4 , further comprising one or more target signal transmission paths configured to carry target signals at frequencies Z of at least 4 GHz where a ratio of Z/X is at least 5, wherein the transmitter is configured to transmit at least one said guard signal over the one or more target signal transmission paths.

10. The guard sensor of claim 1 , wherein the knee frequency is at least 4 GHz, further comprising circuitry included first and second circuit devices connected by one or more target signal transmission paths configured to carry one or more target signals at frequencies Z of at least 4 GHz, wherein at least a portion said one or more target signal transmission paths and the one or more target signals constitute objects that lie within the guarded region.

11. The guard sensor of claim 10 , wherein the memory has stored thereon instructions that, when executed by the processor, cause the processor to:
periodically measure physical characteristic data of the circuitry, operational data of the circuitry, and environmental data related to at least the one or more target signal transmission paths and target signals;
periodically capture the measured data;
generate a dynamic fingerprint based on an aggregation of a first set of the captured data, wherein the dynamic fingerprint is a compound data structure encapsulating the aggregated data;

associate metadata with the dynamic fingerprint;
periodically update the dynamic fingerprint according to successive sets of the captured data; and
compare the updated dynamic fingerprint to a previous dynamic fingerprint, to detect the changes in the dynamic fingerprint as a proxy for EM and physical intrusions on the circuitry within the guarded region.

12. The guard sensor of claim 1 , further comprising first and second circuit assemblies each having a first connector that is physically connected to a common interconnect, at least one said guard sensor residing at least one of said first and second circuit assemblies with said one or more guard signal transmission paths routed through the first connectors on each of said first and second circuit assemblies and the common interconnect such that the physical connectivity of the first and second circuit assemblies constitutes an object in the guarded region.

13. The guard sensor of claim 1 , wherein the objects in the guarded region comprise at least one of circuit devices, signal paths or signals.

14. The guard sensor of claim 1 , wherein the transmitter and receiver are co-located in a common circuit device.

15. The guard sensor of claim 1 , wherein the transmitter and receiver are located on separate circuit devices.

16. The guard sensor of claim 1 , wherein a plurality of guard sensors provide a guard sensor assembly that defines a mesh of guard signal transmission paths that provide both the EM and physical barrier to intrusion of a common guarded region, wherein said guard sensors are interconnected to detect an intrusion of the common guarded region.

17. The guard sensor of claim 16 , wherein at least first and second guard sensor transmit differe

Assignees

• Raytheon Co

Inventors

• Jennings William
• Hoffman John

Classifications

• H04L63/1416 Primary

  Event detection, e.g. attack signature detection · CPC title

• G08B13/2494

  by interference with electro-magnetic field distribution combined with other electrical sensor means, e.g. microwave detectors combined with other sensor means · CPC title

• G08B13/128

  the housing being an electronic circuit unit, e.g. memory or CPU chip (protecting computer components in secure or tamper resistant housings G06F21/86; protecting computer input devices, e.g. keyboards G06F21/83) · CPC title

• G06F21/75 Primary

  by inhibiting the analysis of circuitry or operation · CPC title

• G06F21/00 Primary

  Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity · CPC title