Tamper detection techniques
AssigneeArm Limited
InventorsVenkata Niranjan Cherukuri, Srinivasan Balakrishnan, Chirumamilla Lakshmana Rao
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Abstract
Various implementations described herein are related to a device having sensing circuitry that receives an input signal and provides an output signal based on sensing a resistance differential between multiple shield resistors or based on sensing a change in voltage across a shield wire of a shield wiring network. The device includes comparing circuitry that receives the output signal and provides an alarm signal based on detecting a tampering event associated with the resistance differential or the change in voltage.
Claims9
A device, comprising:
- sensing circuitry that receives an input signal and provides an output signal based on sensing a resistance differential between multiple metal shield resistors;
- and
- comparing circuitry that receives the output signal and provides an alarm signal based on detecting a tampering event associated with the resistance differential,
- wherein the sensing circuitry has an operational amplifier and the multiple metal shield resistors that are configured to receive the input signal and provide the output signal based on sensing the resistance differential between the multiple metal shield resistors,
- wherein the multiple metal shield resistors have a first metal shield resistor and a second metal shield resistor,
- wherein the first metal shield resistor is coupled between an inverting input of the operational amplifier and ground, and
- wherein the second metal shield resistor is coupled between the inverting input of the operational amplifier and an output of the operational amplifier.
A method, comprising:
- providing shield wiring with wire segments;
- coupling one wire segment of the wire segments to an inverting input of an operational amplifier;
- coupling another wire segment of the wire segments between the inverting input and an output of the operational amplifier;
- sensing a resistance differential or a voltage change across the wire segments with the operational amplifier;
- detecting a tampering event associated with at least one of a cut, an open, a strap, a short, and probing in reference to sensing the resistance differential or the voltage change;
- and
- generating an alarm signal based on detecting the tampering event.
A method comprising:
- providing shield wiring with wire segments;
- coupling the wire segments to an operational amplifier;
- sensing a resistance differential or a voltage change across the wire segments with the operational amplifier;
- detecting a tampering event associated with at least one of a cut, an open, a strap, a short, and probing in reference to sensing the resistance differential or the voltage change;
- and
- generating an alarm signal based on detecting the tampering event,
- wherein coupling the wire segments to the operational amplifier includes:
- coupling a first wire segment of the wire segments between an inverting input of the operational amplifier and ground, and
- coupling a second wire segment of the wire segments between the inverting input of the operational amplifier and an output of the operational amplifier.
Dependencies are inferred from the claim text.