Towards a Framework for Evaluating the Security of Physical-Layer Identification Systems

In recent years researchers have shown that the analogue signalling behaviour of digital devices can be used for identification and monitoring purposes. The basic postulate of these so-called physical-layer identification (PLI) approaches is that devices are sufficiently variable in their behaviour to be distinguishable and that an attacker would be unable to adequately emulate this behaviour. Recent work, however, has shown that at least some PLI implementations can be defeated using electronic equipment capable of generating arbitrarily shaped signals known as arbitrary waveform generators (AWGs).

In this work we first present a framework to determine whether an AWG, specified in terms of resolution, sampling rate, distortion, and noise parameters, could be used to defeat a given PLI system. We then utilise this framework in the formulation of a cost-minimisation problem to find the most cost-effective values of these parameters; i.e. we characterise the least expensive, and hence lowest performing, AWG an attacker would require to defeat a PLI system. The use of the framework is illustrated by applying it to a previously proposed PLI approach. Results indicate that the PLI system could be defeated using an AWG with a substantially lower sampling rate and resolution than the PLI system sampler.