Practical Approach in Verification of Security Systems Using Satisfiability Modulo Theories

The paper presents a novel method for the verification of security protocols’ (SPs)time properties. The new method uses a translation to satisfiability modulo theories (SMT) problem. In our approach, we model protocol users’ behaviours using networks of synchronized timed automata. Suitably specified correctness properties are defined as a reachability property of some chosen states in an automata network. Then, the network of timed automata and the property are translated to an SMT problem and checked using an SMT-solver and a BMC algorithm. We consider the most important time properties of protocol executions using specially constructed time conditions. The new method was also implemented and experimentally evaluated for six well-known SPs. We also compared our new SMT-based technique with the corresponding SAT-based approach.