Visibility Region-Based Near-field Physical Layer Authentication for Extremely Large-Scale Array

This letter addresses security challenges in near-field communication between legitimate users vulnerable to eavesdropping. However, the visibility region is rarely used to construct the user’s signature for security authentication. To address this, we propose a Physical Layer Authentication based on Characteristic Extraction (PLACE) scheme, which constructs a highly distinctive signature by uniquely fusing visibility region boundary points via a non-linear, prime-number-based function, ensuring robust and accurate user identification. Numerical results demonstrate that the proposed scheme enhances communication security, effectively safeguarding transmission reliability and distinguishing between legitimate users and eavesdroppers.