BCAuth: Physical Layer Enhanced Authentication and Attack Tracing for Backscatter Communications

Backscatter communication (BC) enables ultra-low-power communications and allows devices to harvest energy simultaneously. But its practical deployment faces severe security threats caused by nature of openness broadcast. Authenticating backscatter (BDs) is treated as the first line defense. However, complex cryptographic approaches are not desirable due limited computation capability BDs. Existing physical layer authentication schemes cannot effectively support BD mobility, multiple attacker identification location tracing in an integrated way. To tackle these problems, this paper proposes BCAuth, a multi-stage attack scheme based on spatial information BDs realize enhanced for both static mobile After initial identity with position registration, preemptive re-authentication performed according correlation backscattered signal source locations associated BD. By exploiting clustering-based analysis spacial information, BCAuth capable determining number attackers localizing their positions. In addition, we propose reciprocal channel-based method better performance than when able measure received strength (RSS), which also mutual authentication. We theoretically analyze conduct extensive numerical simulations various settings show performance.