Mechanisms for detecting tampering of an electronic device
First Claim
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1. An electronic device comprising:
- a chassis;
a printed wiring board (PWB) having a hole, a fastener installed in the hole thereby securing the PWB to the chassis, the PWB having formed therein a pair of conductive traces, and a cap being an amount of conductive glue covering a part of the fastener and filling electrically insulating gaps between each trace and the fastener to thereby form a conductive path that connects the two traces; and
a sensing circuit coupled to the pair of traces to detect a change in impedance of the path and in response, signal an alert to a data processor that evaluates and logs tamper events in the electronic device.
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Abstract
An electronic device has a chassis, and a printed wiring board (PWB) having a hole. A fastener is installed in the hole thereby securing the PWB to the chassis. A pair of conductive traces is formed in the PWB. A cap, being an amount of conductive glue, covers a part of the fastener and fills an electrically insulating gap between the two traces, to thereby form a conductive path that connects the two traces. A sensing circuit is coupled to the traces, to detect a change in impedance of the path and signal a tamper event alert. Other embodiments are also described and claimed.
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Citations
20 Claims
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1. An electronic device comprising:
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a chassis; a printed wiring board (PWB) having a hole, a fastener installed in the hole thereby securing the PWB to the chassis, the PWB having formed therein a pair of conductive traces, and a cap being an amount of conductive glue covering a part of the fastener and filling electrically insulating gaps between each trace and the fastener to thereby form a conductive path that connects the two traces; and a sensing circuit coupled to the pair of traces to detect a change in impedance of the path and in response, signal an alert to a data processor that evaluates and logs tamper events in the electronic device. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An electronic device comprising:
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a chassis having a conductive portion; a printed wiring board (PWB) having a hole, a conductive fastener having a tool end, the fastener being installed in the hole thereby securing the PWB to the chassis'"'"' conductive portion, the PWB having formed therein a circuit trace, and a cap being a measured amount of conductive glue in contact with and covering the tool end of the fastener and filling an electrically insulating gap between the circuit trace and the tool end to thereby form a conductive path that connects the circuit trace to the chassis'"'"' conductive portion via the fastener; and a sensing circuit coupled to the circuit trace and the chassis'"'"' conductive portion to detect a change in impedance of the conductive path and in response, signal an alert to a data processor that evaluates and logs tamper events in the electronic device. - View Dependent Claims (8, 9)
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10. An electronic device comprising:
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a chassis; a printed wiring board (PWB) having a plurality of holes, and a plurality of fasteners installed in the holes, respectively, thereby securing the PWB to the chassis, wherein for each hole the PWB has formed therein a respective pair of conductive traces and a respective cap, being a measured amount of conductive glue, covering a part of the fastener that is in the hole and filling electrically insulating gaps between each fastener and each of the respective traces to thereby form a respective conductive path with the pair of traces, said respective conductive paths being coupled to each other in series; and a sensing circuit coupled to said series-coupled respective conductive paths to detect a change in impedance therein and in response, signal an alert to a data processor that evaluates and logs tamper events in the electronic device. - View Dependent Claims (11, 12, 13, 14, 15)
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16. An electronic device comprising:
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a chassis; a printed wiring board (PWB) having a plurality of holes, and a plurality of fasteners installed in the holes, respectively, thereby securing the PWB to the chassis, wherein for each hole the PWB has formed therein a respective pair of conductive traces and a respective cap, being a measured amount of conductive glue, covering a part of the fastener that is in the hole and filling electrically insulating gaps between each fastener and each of the respective traces to thereby form a respective conductive path with the pair of traces, said respective conductive paths being connected as a randomly accessible sensor array; and a selection and sensing circuit coupled to said randomly accessible sensor array, to pass a current through any one of the respective conductive paths at a time and then detect a change in impedance therein, the selection and sensing circuit to, in response to detecting the change in impedance, signal an alert to a data processor that evaluates and logs tamper events in the electronic device, wherein the alert identifies said one of the respective conductive paths in which the impedance change was detected. - View Dependent Claims (17, 18, 19, 20)
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Specification