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

TL;DR

Quantum threats necessitate resilient RIS-enabled ISAC for 6G UAV corridors. The paper proposes QRTM, a framework that unifies classical, quantum-ready, and quantum-aided adversaries with post-quantum cryptography (ML-KEM for key exchange and Falcon for signatures) and RIS-coded scene authentication via GLRT, all coordinated by a Secure ISAC Utility that jointly optimizes secrecy rate, spoofing detection, and throughput with an $O(n^2)$ scheduler. Monte Carlo evaluations in 3GPP Rel-19 mid-band urban canyon models show spoof-detection probability $P_D o 0.99$ at $P_{FA}=10^{-3}$, secrecy-rate retention $>90 ext{ extsuperscript{?}}$, and about a $25 ext{ extsuperscript{?}}$ throughput improvement over baselines, demonstrating a standards-aligned path to reliable quantum-resilient ISAC for UAV corridors. The approach offers practical security guarantees for quantum-capable attackers in smart-city and non-terrestrial networks by integrating cryptographic trust anchors with physical-layer security and efficient RIS control.

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.

Figures (5)

• Figure 1: Quantum Resilient Threat Modeling Framework for Secure RIS-Assisted ISAC in 6G UAV Corridors
• Figure 2: ROC of RIS-coded scene authentication at midband ($f_c{=}10$ GHz, $M{=}256$, $M_{\text{code}}{=}64$, $K{=}400$). At $P_{\mathrm{FA}}{=}10^{-3}$, QRTM attains $P_D\!\approx\!1$ while public-coded, static, and No-RIS baselines degrade significantly.
• Figure 3: Secrecy rate $C_s$ vs. user SNR. RIS beamforming raises $\rho_u$; with confidential control, the scheduler can choose $\boldsymbol{\phi}$ that disfavors likely eavesdropper directions (which adversaries cannot anticipate), yielding higher $C_s$ over time. Cryptography does not change instantaneous SNRs; it protects the control that selects $\boldsymbol{\phi}$.
• Figure 4: Secure ISAC Utility $U(\tau)$ at 10 dB with $(\lambda_1,\lambda_2,\lambda_3){=}(0.34,0.33,0.33)$. QRTM peaks at $\tau^\star\!\approx\!0.05$ and dominates for $\tau\in[0.05,0.9]$, evidencing the comms–sensing balance.
• Figure 5: Runtime comparison of QRTM’s separable optimisation ($\mathcal{O}(n M B_\phi)$) versus greedy inter-UAV scheduling ($\mathcal{O}(n^2)$) and naïve exhaustive search ($\Theta(n\,2^{B_\phi M})$).