Quantum-Resilient Threat Modelling for Secure RIS-Assisted ISAC in 6G UAV Corridors

Abstract

The rapid deployment of unmanned aerial vehicle (UAV) corridors in sixth-generation (6G) networks requires safe, intelligence-driven integrated sensing and communications (ISAC). Reconfigurable intelligent surfaces (RIS) enhance spectrum efficiency, localisation accuracy, and situational awareness, while introducing new vulnerabilities. The rise of quantum computing increases the risks associated with harvest-now-decrypt-later strategies and quantum-enhanced spoofing. We propose a Quantum-Resilient Threat Modelling (QRTM) framework for RIS-assisted ISAC in UAV corridors to address these challenges. QRTM integrates classical, quantum-ready, and quantum-aided adversaries, countered using post-quantum cryptographic (PQC) primitives: ML-KEM for key establishment and Falcon for authentication, both embedded within RIS control signalling and UAV coordination. To strengthen security sensing, the framework introduces RIS-coded scene watermarking validated through a generalised likelihood ratio test (GLRT), with its detection probability characterised by the Marcum Q function. Furthermore, a Secure ISAC Utility (SIU) jointly optimises secrecy rate, spoofing detection, and throughput under RIS constraints, enabled by a scheduler with computational complexity of O(n^2). Monte Carlo evaluations using 3GPP Release 19 mid-band urban-canyon models (7-15 GHz) demonstrate a spoof-detection probability approaching 0.99 at a false-alarm rate of 1e-3, secrecy-rate retention exceeding 90 percent against quantum-capable adversaries, and signal-interference utilisation improvements of about 25 percent compared with baselines. These results show a standards-compliant path towards reliable, quantum-resilient ISAC for UAV corridors in smart cities and non-terrestrial networks.