Opinion: PHY-Layer Security is no Alternative to Cryptography

Abstract

In recent works, numerous physical-layer security systems have been proposed as alternatives to classic cryptography. Such systems aim to use the intrinsic properties of radio signals and the wireless medium to provide con dentiality and authentication to wireless devices. However, fundamental vulnerabilities are o en discovered in these systems shortly a er their inception. We therefore challenge the assumptions made by existing physical-layer security systems, and postulate that weaker assumptions are needed in order to adapt for practical scenarios. We also argue that if no computational advantage over an adversary can be ensured, secure communication cannot be realistically achieved.