Reciprocity-Driven Physical Layer Key Generation for Wireless Body Area Networks

Abstract

This study proposes a lightweight, reciprocity-driven physical layer key generation scheme tailored for secure communication in Wireless Body Area Networks (WBANs). By harnessing the inherent randomness and temporal variation of on-body wireless channels, cryptographic keys are dynamically generated between wearable devices without reliance on pre-distributed secrets or computationally intensive algorithms. The protocol employs adaptive channel probing and quantization, followed by efficient error reconciliation and privacy amplification, ensuring strong key agreement even under mobility and diverse body movements. Experimental evaluations on a real WBAN testbed demonstrate high key generation rates, low bit mismatch, and resilience to passive eavesdropping, validating the scheme’s suitability for resource-constrained, low-power healthcare wearables. The results highlight the potential of physical-layer security as a practical solution for next-generation, privacy-aware health monitoring systems.