SCOBE: A Schedule Randomization Protocol for Obfuscation Against Timing Inference Attacks in Hard Real-Time Systems

The high degree of predictability in hard real-time systems makes it possible for adversaries to launch timing inference attacks such as those based on side-channels and covert-channels. We present SCOBE, an obfuscation engine aimed at randomizing the schedule for such systems while still providing the real-time guarantees that are necessary for their safe operation. This paper also analyzes the effect of these mechanisms by presenting schedule entropy – a metric to measure the uncertainty (as perceived by attackers) introduced by SCOBE. These mechanisms will increase the difficulty for would-be attackers thus improving the overall security guarantees for hard real-time systems.Ope