Cross-Sector Cascade Resilience in the Post-Quantum Transition: Coupled-Network Theorems and Stress-Testing Algorithms for Finance–Telecom–Industrial Control Systems (ICS)

Abstract: This study investigates cascade resilience during the post-quantum transition across coupled finance, telecommunications, and industrial control systems (ICS), using marine robotics with edge autonomy as the operational anchor. Migration failures can disable services even when links exist, because suite negotiation, certificates, or key management become incompatible across stakeholders. A coupled-network stress-testing method is parameterized using real public datasets: NOAA buoy observations (sea-state–driven telecom stress proxy), the CISA KEV catalog (exploited OT/ICS pressure), and World Bank maritime indicators (throughput context). Results show super-additive cascades under compound stress and measurable mitigation when edge autonomy reduces connectivity criticality. Keywords post-quantum transition; cascade resilience; coupled networks; multilayer systems; marine robotics; edge autonomy; OT/ICS security; crypto-agility; stress testing; graph–Bayes pipelines.