A multi-layered and kill-chain based security analysis framework for cyber-physical systems

This paper introduces a novel framework for understanding cyber attacks and the related risks to cyber-physical systems. The framework consists of two elements, a three-layered logical model and reference architecture for cyber-physical systems, and a meta-model of cyber-physical system attacks that is referred to as the cyber-physical system kill-chain. The layered reference architecture provides a systematic basis for studying how the causal chain associated with cyber perturbations can be traced all the way to physical perturbations. The cyber-physical system kill-chain describes the progressive stages of attacks to illuminate the steps required for an attacker to launch a successful attack against a cyber-physical system. The proposed framework offers a novel approach for comprehensively studying the elements of cyber-physical system attacks, including the attacker objectives, cyber exploitation, control-theoretic properties and physical system properties. The framework is evaluated using a simulated unmanned aerial system and the results of the evaluation are discussed. The longer-term goal is to use the framework as a means to deduce cyber-physical system security properties and to enumerate the principles for designing systems that are resilient to cyber attacks.