Robust Tracking-Based PHY-Authentication in mmWave MIMO Systems

Physical Layer Authentication (PLA) is a topic of considerable interest in ensuring strong security for upcoming wireless networks. However, existing PLA methods face challenges in maintaining performance in dynamic environments. To overcome this, we propose a novel tracking-based PLA approach, utilizing properties of the beamspace multiple-input multiple-output (MIMO) channel in narrowband millimeter-wave (mmWave) networks. Specifically, In particular, the proposed technique involves extracting a distance signature vector from the positions of the principal components within the beamspace MIMO channel representation. These components are then sorted in descending order based on their indices. To address mobility concerns in dynamic settings, a tracking filter is introduced. This filter allows the authentication system to continuously track and update the stored signature, enhancing overall authentication performance. Additionally, the proposed technique is extended to ultra-wideband signaling. In this extension, the richness of the derived signature is further improved by exploiting the beam squint effect, contributing to a more robust authentication process. Simulation results demonstrate that our approach overcomes the limitations of previous methods, resulting in improved authentication performance measured by detection and false alarm rates.