9. A Strategy for Structuring and Formalising Attack Patterns

We have created a framework for modelling security that divides computer incidents into their stages of access, use and effect. In addition, we have developed a three-layer architectural model to examine incidents with the social, logical and physical levels. Our ontology that combines the architectural and incident models provides the basis for a suitable semantics for attack patterns, where the entities and relationships between them can be precisely defined. The current informality of these patterns means that their utility is limited to manual use, so we plan to adapt existing work on formalising design patterns to attack patterns, to aid the detection of attack patterns leading to the possible creation of effective defensive controls. A specification in logic, which is progressively refined into code, is a common method of developing high integrity and secure software, but there are additional issues in system protection, as the system is a diverse set of components housing different and unrelated functionality rather than a single program. The attack patterns form a logical specification, which can be intersected with the model of the defence to determine the corresponding defensive observations and actions to counter the attacks. This would allow convincing reasoning about possible defensive response measures, and holds out the possibility of proving security against certain types of attacks. We outline a roadmap for formulating attack patterns in our ontology and then translating them in logic.