Physical Layer Authentication With Channel Knowledge Maps in Indoor Environments

2026-06-25

AI Summary

This work addresses the challenge of reliable physical-layer authentication in indoor mobile environments, where severe channel time-variability caused by multipath and occlusion undermines conventional approaches. To overcome this limitation, the study introduces, for the first time, a channel knowledge map tailored to such dynamic scenarios. By leveraging multiple access points to estimate path loss and angle of arrival of dominant propagation paths, the method performs spatial neighborhood matching against a ray-tracing-based channel map constructed from prior positional information. This enables robust authentication even under adverse channel conditions. Experimental validation demonstrates that the proposed approach achieves high reliability in typical indoor settings and maintains strong security guarantees against both random and optimal adversarial attacks.

Abstract

Physical layer authentication (PLA) allows to authenticate the user by comparing measurements over time, assuming their time consistency or by modeling their evolution. However, these assumptions become problematic when devices are in motion and in indoor environments due to multipath propagation and obstructions. In this paper, we propose a PLA mechanism for moving devices in indoor environments, where multiple access points (APs) estimate the dominant channel tap path loss (PL) and angle of arrival (AoA) from the received signals and compare them with previously collected channel knowledge maps (CKMs). Specifically, the measurements are compared to those in the neighborhood of the previously known position obtained from CKMs. A comprehensive security analysis is conducted under both random and optimal attacks. Numerical results in a representative indoor scenario, with CKM obtained via ray tracing, validate the effectiveness of the proposed PLA approach.

Problem

• Physical Layer Authentication
• Indoor Environments
• Multipath Propagation
• Channel Knowledge Maps
• Moving Devices

Innovation

• Physical Layer Authentication
• Channel Knowledge Maps
• Angle of Arrival
• Path Loss
• Indoor Localization