Constraint-based Analysis of Security Properties

Model checking is a verification method developed to test finite-state systems (e.g., communication protocols, hardware circuits) against properties expressed as formulas in temporal logic. The method has proved successful in finding design flaws in many real-life applications. Nevertheless, models¿especially of software systems¿often tend to have unbounded number of states. Traditionally, verifying such systems using model checkers requires first abstracting the systems into finite-state models. We introduce a unified, automata-based representation for infinite-state systems and linear temporal logic properties, and describe a model-checking technique for such specifications. We exploit constraint solving and logic programming to implement an efficient and robust infrastructure for our model checker, and apply this implementation to analyze vulnerabilities of computer systems and configurations.