Online Distributed Schedule Randomization to Mitigate Timing Attacks in Industrial Control Systems

Industrial control systems (ICSs) consist of a large number applications that are associated with periodic real-time flows hard deadlines. To facilitate large-scale integration, remote and co-ordination, wireless sensor actuator networks (WSANs) form the main communication framework in most ICSs. Among existing WSAN protocols, WirelessHART is suitable protocol for The communications network time-division multiple access (TDMA) based. satisfy deadlines flows, schedule pre-computed. same repeated over every hyperperiod, i.e. , lowest common periods flows. However, malicious attacker can exploit repetitive behavior flow schedules to launch timing attacks, e.g., selective jamming attacks. mitigate we propose an online distributed randomization strategy randomizes time-slots at each device without violating deadlines, while ensuring closed-loop stability. increase extent further, reduce energy consumption system, incorporate period adaptation adjusts transmission depending on stability loops runtime. We use Kullback-Leibler divergence Prediction Probability slots as two metrics evaluate performance our proposed strategy. compare offline centralized Experimental results show generated by \(10\% \) - \(15\% more diverse \(5\% less predictable average compared when base keys vary between 4 6 12 32 respectively under all slot utilization (number occupied hyperperiod). On incorporating adaptation, reduces \(46\% power average.