Method of creating an electronically readable optical fingerprint to protect an electrical interconnect

Abstract

An electrical system includes a signal security detection system that performs a method for determining the security of an interconnect. An interconnect extends between a first device and a second device. The interconnect has at least one conductive path aligned in a direction between the first and second devices. A light source is configured to transmit light through the interconnect, and an optical detector is configured to receive the light through the interconnect. A processor records a first optical feature of the interconnect based on light received a first time at the optical detector, records a second optical feature of the interconnect based on light received a second time at the optical detector, and verifies the second optical feature based on the first optical feature to determine the security of the interconnect.

Description

Technical Field

[0001] This invention relates to the security of electronic communications, and more specifically, to a system and method for determining the integrity of electrical interconnections between electrical devices. Prior Technology

[0002] In various electrical systems, the security of electronic communication between system components is a critical issue. Interconnections between two electrical devices provide a conductive path through which electrical signals can be transmitted back and forth. Electrical interconnections are a vulnerability because accessing an interconnect provides a way to obtain information exchanged along that interconnect. While electrical monitoring of interconnects is possible, such monitoring can degrade communication performance and requires additional equipment. Therefore, there is a need to monitor the security of electrical interconnects that can be integrated into the electrical system without causing performance degradation. Summary of the Invention

[0003] According to one embodiment of the present invention, a method for determining interconnect security is disclosed. Light from a light source is transmitted through an interconnect between a first device and a second device, the interconnect comprising at least one conductive path aligned along a direction between the first and second devices. A first optical feature of the conductive path is recorded based on light received at an optical detector during the first passage through the interconnect. A second optical feature of the conductive path is recorded based on light received at the optical detector during the second passage through the interconnect. The second optical feature is verified based on the first optical feature to determine the interconnect security.

[0004] According to another embodiment of the present invention, a signal security detection system is disclosed. The system includes an interconnect between a first device and a second device, the interconnect having at least one conductive path aligned along the direction between the first and second devices, a light source for transmitting light through the interconnect, an optical detector for receiving light through the interconnect, and a processor. The processor is configured to record a first optical feature of the interconnect based on light received a first time at the optical detector, record a second optical feature of the interconnect based on light received a second time at the optical detector, and verify the second optical feature based on the first optical feature to determine the security of the interconnect.

[0005] According to another embodiment of the present invention, an electrical system is disclosed. The electrical system includes a first device, a second device, and an interconnection between the first and second devices, the interconnection having at least one conductive path aligned along a direction between the first and second devices. The system also includes a light source for transmitting light through the interconnection, an optical detector for receiving light through the interconnection, and a processor. The processor is configured to record a first optical feature of the interconnection based on light first received at the optical detector, record a second optical feature of the interconnection based on light second received at the optical detector, and verify the second optical feature based on the first optical feature to determine the security of the interconnection.

[0006] Additional features and advantages are achieved through the technology of this invention. Other embodiments and configurations of the invention are described in detail herein and are considered part of the claimed invention. For a better understanding of the advantages and features of the invention, please refer to the specification and drawings. Simple Explanation of the Diagram

[0007] The object considered to be the subject of this invention is specifically pointed out and explicitly claimed in the claims at the end of the specification. The foregoing and other features and advantages of this invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein: [Figure 1] A schematic diagram of an electrical system in an exemplary embodiment. [Figure 2] Perspective view of the bonding material used to form the interconnection of the electrical system of Figure 1. [Figure 3] Arrangement of the bonding materials between the first and second devices of the electrical system. [Figure 4] A diagram illustrating the role of the arrangement of conductive particles in forming optical features. [Figure 5] A diagram illustrating a method for enhancing optical features using dyes. [Figure 6] A diagram of an electrical system in one embodiment, showing the optical path of light propagating through interconnects. [Figure 7] A diagram of an electrical system in one embodiment, showing the alternative optical path for light to propagate through interconnects. Implementation

[0008] Figure 1 illustrates a schematic diagram of an electrical system 100 in an exemplary embodiment. The electrical system 100 includes a first device 102, a second device 104, and an interconnect 106 between the first device 102 and the second device 104 for transmitting safety signals. The interconnect 106 includes a conductive path for transmitting signals between the first device 102 and the second device 104. The conductive path may be a conductive path or conductive structure for transmitting electrical signals between the first device 102 and the second device 104. A coordinate system 108 is shown to identify the alignment orientation of the various components of the electrical system. For illustrative purposes, the interconnect 106 extends along the z-axis to connect the first device 102 to the second device 104. The z-axis is aligned in the direction between the first device 102 and the second device 104.

[0009] Electrical system 100 further includes a signal security detection system 110 adapted to determine whether the signal path provided by interconnect 106 is secure, or whether the interconnect (and, by extension, the signal path) has been altered or degraded. Signal security detection system 110 includes a light source 112 that illuminates interconnect 106 with a light beam and an optical detector 114a that receives the light beam after it interacts with interconnect 106. In various embodiments, optical detector 114a includes one or more photodetectors. Light source 112 and optical detector 114a are coupled to processor 116. Processor 116 can activate light source 112 to generate a light beam. As the path of the light beam passes through interconnect 106, the light beam is transmitted through interconnect 106 such that a pattern of light is received at optical detector 114a. Processor 116 records or generates an optical signature based on the pattern of light. Based on the first and second optical signatures obtained, processor 116 can use the methods disclosed in this invention to determine the integrity of interconnect 106, i.e., whether the interconnect is secure or has been altered.

[0010] In one embodiment, the light source 112 may be an integrated or embedded component of the first device 102, and the optical detector 114a may be an integrated or embedded component of the second device 104. Therefore, the optical features are based on the image of light transmitted via the interconnect 106. Alternatively, the signal security detection system 110 may include an optical detector 114b as an integrated or embedded component of the first device 102. The optical features at the optical detector 114b are based on the image of light reflected from the interconnect 106. The light source 112 may alternatively be located within the second device 104. However, the placement of the light source 112 and the optical detectors 114a, 114b in either the first device 102 or the second device 104 is not intended to limit the invention. In an alternative embodiment, the light source 112 and the optical detectors 114a, 114b may be external to the first device 102 and / or the second device 104.

[0011] Figure 2 shows a perspective view of the bonding material 200 used to form the interconnect 106 of Figure 1. The bonding material 200 comprises a matrix material 202, such as an epoxy resin material, and a plurality of conductive particles disposed within the matrix material 202. The matrix material is a transparent or translucent material. In various embodiments, the conductive particles are conductive particles 204. The conductive particles 204 may be optically opaque to the visible and / or infrared bands of the electromagnetic spectrum.

[0012] Figure 3 illustrates the arrangement of bonding materials forming an interconnect 106 between the first device 104 and the second device 104. Conductive particles 204 are arranged along the z-direction to form conductive pillars 320, which are also arranged along the z-direction. The conductive particles 204 within the conductive pillars 302 establish conductive paths 318 between the first device 102 and the second device 104. The conductive pillars 302 are characterized by columnar or cylindrical volumes, wherein the conductive particles 204 are randomly arranged within the cylindrical volume or have a non-deterministic arrangement within the cylindrical volume. Each cylindrical volume is spaced apart from adjacent cylindrical volumes by regions of epoxy resin material having few or no conductive particles 204. The conductive pillars 320 can be formed by applying a magnetic field in the z-direction during bonding or by slicing a composite material with conductive fibers oriented in a polymer matrix and substantially perpendicular to the fiber direction.

[0013] Figure 4 shows a diagram 400 illustrating the role of the arrangement of conductive particles 204 in forming optical features. Optical features are created by passing light from light source 112 through interconnects to record it at optical detector 114a. Optical detector 114a may contain a plurality of photosensitive devices 402. The conductive particles 204 produce randomly arranged shadows 404 at optical detector 114a.

[0014] Due to the unique pattern presented by the random arrangement of the conductive particles 204, it is difficult for an individual to alter the interconnect without significantly changing the optical characteristics. Furthermore, because the conductive particles 204 are randomly arranged, it is difficult for an individual that alters the interconnect to reproduce the original arrangement of the conductive particles 204. Therefore, any changes to the interconnect can be identified by recognizing changes in the optical characteristics.

[0015] To check the optical signal, light source 112 is activated and a first optical feature is acquired based on the original arrangement of conductive particles 204. A second time, after the first acquisition, the light source is activated again and a second optical feature is acquired. Processor 116 verifies the second optical feature against the first optical feature. If the second optical feature substantially matches or is identical to the first optical feature, processor 116 outputs a verification signal to indicate that the interconnect is secure and has not been altered. If the second optical feature substantially does not match or differs from the first optical feature, processor 116 outputs a warning signal to indicate that the interconnect is no longer secure or has been altered.

[0016] Figure 5 illustrates a method for enhancing optical features using dye 502. During the bonding process, dye 502 is introduced into one or more selected locations in the bonding material 200 between the light source 112 and the optical detector 114a. Dye 502 can affect the wavelength recorded on a portion of the optical feature. Therefore, the optical feature incorporates the effect of the dye on light transmitted through the interconnects. The random placement of dye 502 increases the security provided by the optical feature.

[0017] Figure 6 illustrates an electrical system 100 in one embodiment, showing an optical path 602 of light passing through interconnect 106. A light source 112 is disposed within a first device 102, and an optical detector 114a is disposed within a second device 104. Light from the light source 112 reaches the optical detector 114a via an optical path 602, which is formed primarily by transmission and refraction through the bonding material and reflection from conductive particles.

[0018] Figure 7 illustrates an electrical system 100 in one embodiment, showing an alternative optical path 702 through which light passes through interconnect 106. A light source 112 and an optical detector 114b are both disposed within the first device 102. Light from the light source 112 reaches the optical detector 114b via the alternative optical path 702, formed primarily by reflection from conductive particles.

[0019] While this invention discloses conductive paths that include conductive particles, this is not intended to limit the invention. In various embodiments, the conductive path may be a thermally conductive path that includes thermally conductive particles. Furthermore, the conductive path may be both electrically and thermally conductive and may include particles that are both electrically and thermally conductive.

[0020] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that, when used in this specification, the terms "comprising" and / or "including" specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, element components, and / or combinations thereof.

[0021] All means or steps, functional terms, corresponding structures, materials, actions, and equivalent scopes of the elements described in the following claims are intended to encompass any structure, material, or action used to perform a function in combination with other claimed elements, as specifically claimed. The description of the invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure of its detailed form. Many modifications and variations will be apparent to those skilled in the art to which this invention pertains without departing from the scope and spirit of the invention. The embodiments were chosen and described in order to best explain the principles and practical application of the invention, and to enable those skilled in the art to understand the various embodiments with various modifications suitable for the particular purpose considered.

[0022] While preferred embodiments have been described, it should be understood that various modifications and alterations falling within the scope of the appended claims can be made now and in the future by those skilled in the art to which this invention pertains. These claims should be interpreted as maintaining appropriate protection for the disclosures of the initial description.

[0023] 100: Electrical System 102: First Device 104: Second Device 106: Interconnection 108: Coordinate System 110: Signal Safety Detection System 112: Light source 114a: Optical detector 114b: Optical detector 116: Processor 200: Bonding material 202: Matrix material 204: Conductive particles 302: Conductive post 318: Conductive path 400: Diagram 402: Photosensitive device 404: Shadow 500: Diagram 502: Dye 600: Diagram 602: Optical path 700: Diagram 702: Optical Path

Claims

1. A method for determining the security of an interconnection between a first device and a second device, comprising: transmitting light for the first time from a light source embedded in the first device via the interconnection, the interconnection including a bonding material located between the first device and the second device and at least one conductive path through the bonding material from the first device to the second device, the at least one conductive path being adapted to transmit an electrical signal from the first device to the second device, wherein the light source is embedded in the first device, wherein the light passes through the bonding material and interacts with the at least one conductive path within the bonding material to form a first spatial pattern of light and shadow; receiving the first spatial pattern of light and shadow at an optical detector; recording the first spatial pattern of light and shadow as a first optical feature of the conductive path; transmitting the light for the second time from the light source via the bonding material to interact with the at least one conductive path to form a second spatial pattern of light and shadow; recording the second spatial pattern of light and shadow as a second optical feature of the conductive path; and comparing the first optical feature with the second optical feature to determine the security of the interconnection.

2. The method as described in claim 1, wherein, The at least one conductive path includes a conductive post aligned between the first device and the second device, the conductive post including conductive particles with a nondeterministic arrangement within a columnar volume extending from the first device to the second device, wherein the first optical feature and the second optical feature include the effect of the nondeterministic arrangement.

3. The method as described in claim 1, further comprising irradiating the bonding material with the light to record at least one of the first optical feature and the second optical feature.

4. The method as described in claim 3, wherein, It further includes recording at least one of the first optical feature and the second optical feature at an optical detector embedded in the first device.

5. The method as described in claim 3, wherein, It further includes recording at least one of the first optical feature and the second optical feature at an optical detector embedded in the second device.

6. The method as described in claim 4, wherein, The light source produces light in at least one of the visible and infrared bands.

7. The method as described in claim 1, wherein, It further includes forming the interconnect with a dye disposed at one of the selected locations in the interconnect, wherein the first optical feature and the second optical feature include the effect of the dye.

8. A signal security detection system, comprising: an interconnect between a first device and a second device, the interconnect including a bonding material located between the first device and the second device and at least one conductive path through the bonding material from the first device to the second device, the at least one conductive path being adapted to transmit an electrical signal from the first device to the second device; and a light source embedded in the first device for transmitting light through the interconnect; an optical detector for receiving the light through the interconnect; and a processor configured to: record a first optical feature of the interconnect at the optical detector for the first time, wherein the first optical feature is generated by the light from the light source interacting with the bonding material and the at least one conductive path within the bonding material for the first time, and receive a first spatial pattern of light and shadow generated at the optical detector; At the optical detector, a second optical feature of the interconnect is recorded for the second time, wherein the second optical feature is a second spatial pattern of light and shadow caused by the light from the light source passing through the bonding material for the second time, interacting with the at least one conductive path in the bonding material, and being received at the optical detector; and the first optical feature and the second optical feature are compared to determine the security of the interconnect.

9. The signal security detection system as described in claim 8, wherein, The at least one conductive path includes a conductive post aligned between the first device and the second device, the conductive post including conductive particles with a nondeterministic arrangement within a columnar volume extending from the first device to the second device, wherein the first optical feature and the second optical feature include the effect of the nondeterministic arrangement.

10. The signal security detection system as described in claim 8, wherein, The optical detector is embedded within the first device.

11. The signal security detection system as described in claim 8, wherein, The optical detector is embedded within the second device.

12. The signal security detection system as described in claim 8, wherein, The light source produces light in at least one of the visible and infrared bands.

13. The signal security detection system as described in claim 8, wherein, It further includes a dye disposed at one of the selected locations in the electrical interconnect, wherein the first optical feature and the second optical feature include the effect of the dye on light.

14. An electrical system comprising: a first device; a second device; an interconnect between the first device and the second device, the interconnect including a bonding material located between the first device and the second device and at least one conductive path through the bonding material from the first device to the second device, the at least one conductive path being adapted to transmit an electrical signal from the first device to the second device; a light source embedded in the first device for transmitting light through the interconnect; an optical detector for receiving the light through the interconnect; and a processor configured to: record, at the optical detector, a first optical feature of the interconnect for the first time, wherein the first optical feature is a first spatial pattern of light and shadow resulting from the light from the light source interacting with the bonding material and the at least one conductive path within the bonding material for the first time, and receive at the optical detector the resulting light and shadow. At the optical detector, a second optical feature of the interconnect is recorded for the second time, wherein the second optical feature is a second spatial pattern of light and shadow caused by the light from the light source passing through the bonding material for the second time, interacting with the at least one conductive path in the bonding material, and being received at the optical detector; and the first optical feature and the second optical feature are compared to determine the security of the interconnect.

15. The electrical system as described in claim 14, wherein, The at least one conductive path includes a conductive post aligned between the first device and the second device, the conductive post including conductive particles with a nondeterministic arrangement within a columnar volume extending from the first device to the second device, wherein the first optical feature and the second optical feature include the effect of the nondeterministic arrangement.

16. The electrical system as claimed in claim 14, wherein the optical detector is embedded in one of the first device and the second device.

17. The electrical system as described in claim 14, wherein, The light source produces light in at least one of the visible and infrared bands.

18. The electrical system as described in claim 14, wherein, It further includes a dye disposed at one of the selected locations in the electrical interconnect, wherein the first optical feature and the second optical feature include the effect of the dye on light.

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