  We consider the problem of provably securing a given control loop
implementation in the presence of adversarial interventions on data exchange
between plant and controller. Such interventions can be thwarted using
continuously operating monitoring systems and also cryptographic techniques,
both of which consume network and computational resources. We provide a
principled approach for intentional skipping of control loop executions which
may qualify as a useful control theoretic countermeasure against stealthy
attacks which violate message integrity and authenticity. As is evident from
our experiments, such a control theoretic counter-measure helps in lowering the
cryptographic security measure overhead and resulting resource consumption in
Control Area Network (CAN) based automotive CPS without compromising
performance and safety.

Cryptography and Security;Systems and Control;Systems and Control