Enhanced Two-Way Privacy-Preserving PHY-Layer Authentication for UAV-Assisted MIMO Systems

Authentication is a crucial method for ensuring the security of the unmanned aerial vehicle (UAV)-assisted communication systems; however, it also raises concerns about the leakage of private data. To address this problem, this paper focuses on the problem of identity authentication with privacy-preserving consideration. We propose a two-way privacy-preserving physical layer (PHY-Layer) authentication framework in a UAV-assisted multiple-input multiple-output (MIMO) communication system, by exploiting the carrier frequency offset (CFO) characterizing UAV identity and CFO-based session keys constructed by elliptic curve cryptography (ECC) to encrypt data frames. In particular, we first employ a MOOSE algorithm to extract the hardware fingerprint feature related to UAV, and based on the extracted CFO feature parameters, we devise an ECC-based algorithm for a session key negotiation. To achieve identity validation for the network parties, we establish a two-way authentication framework based on the resulting CFO feature parameters, and apply the CFO-based session key to encrypt data frames for avoiding the leakage of private data. Moreover, we derive the closed-form analytical expressions for the probabilities of the detection and false alarm for the rigorous performance analysis. Finally, we provide extensive numerical results to validate the proposed theoretical model and demonstrate its effectiveness in both identity authentication and privacy preservation. In comparison with the prior scheme, the proposed framework has a better robustness and privacy.