Pattern-Based Formal Approach to Analyse Security and Safety of Control Systems

Increased openness and interconnectedness of safety-critical control systems calls for techniques enabling an integrated analysis of safety and security requirements. Often safety and security requirements have intricate interdependencies that should be uncovered and analysed in a structured and rigorous way. In this paper, we propose an approach that facilitates a systematic derivation and formalisation of safety and security requirements. We propose the specification and refinement patterns in Event-B that allow us to specify and verify system behaviour and properties in the presence of both accidental faults and security attacks and analyse interdependencies between safety and security requirements.