Work-in-Progress: Control Skipping Sequence Synthesis to Counter Schedule-based Attacks

We present an ongoing work on countermeasure design against timing attacks specific to real-time safety-critical Cyber Physical Systems (CPS). Such attacks use timing side channels exposed due to worst-case response time based deterministic scheduling decisions. We propose a methodology to partially nullify this determinism by skipping certain control task executions and related data transmissions. As a proof of concept, we demonstrate how such strategic randomization makes it difficult to launch stealthy timing attacks on controller area network (CAN) based systems.