SkyLock: A Unified Multi-Layer Authentication and Key Management Framework for 6G Non-Terrestrial Networks

We propose SKYLOCK, a unified multi-layer authentication and key management framework for 6G non-terrestrial networks (NTNs) spanning space–air–ground segments. SKYLOCK comprises a quantum-resistant authentication protocol (QRAP), a hierarchical key management system (HKMS), and a fast handover security protocol (FHSP) that jointly deliver low-latency, formally reasoned security under NTN constraints. Evaluation indicates up to 42% lower authentication latency in LEO, 38% in MEO, and 42% in GEO compared to 5G-AKA, and 56% lower handover latency with 79% fewer packet losses. We provide a threat model, formal properties, and implementation guidance for standardisation and deployment.