Tamper protection mesh in an electronic device

摘要

A technique for tamper protection in an electronic device is disclosed. A conductive mesh is affixed onto one or more interior surfaces of the outer housing of the device. The mesh includes one or more conductive traces coupled to one or more detectors within the device. The detector can detect an open-circuit or short-circuit condition resulting from an unauthorized attempt to open the housing, and output a signal to trigger an appropriate countermeasure. The electrical contacts along the trace that are monitored can be selected differently from one manufactured unit to the next, and can be selected based on a randomness function. The selection of contacts may be made during or after manufacturing of the device. The mesh can include multiple metal traces that run very close together, in parallel, across one or more interior surfaces of the housing, allowing detection of both open-circuit and short-circuit conditions.

主权项

1. A payment card reader with built-in tamper protection, comprising:
a card interface to read data from a payment card; circuitry coupled to the card interface, including a memory and a processor to control operation of the payment card reader; a housing that encloses the circuitry; a connector through which the payment card reader can communicate with a hand-held mobile device during a payment transaction; a first metal trace affixed to an interior surface of the housing; a first detector coupled to the first metal trace, to detect a first electrical condition that occurs in response to tampering with the housing, and in response to the first electrical condition, to output a signal that causes a function of the payment card reader or the hand-held mobile device to be disabled; and a multiplexer having a plurality of inputs, each of the inputs coupled to a separate one of a plurality of contacts on the first metal trace, the multiplexer configured to respond to a first control signal by selecting a first one of the plurality of inputs via which the first detector is to monitor for the first electrical condition and to respond to a second control signal by selecting a second one of the plurality of inputs via which the first detector is to monitor for the first electrical condition, wherein each of the first control signal and the second control signal is generated based on a randomness function.