Synthesising certificates in networks of timed automata

The authors present an automatic method for the synthesis of certificates for components in embedded real-time systems. A certificate is a small homomorphic abstraction that can transparently replace the component during model checking: if the veri. cation with the certificate succeeds, then the component is guaranteed to be correct; if the veri. cation with the certificate fails, then the component itself must be erroneous. The authors give a direct construction, based on a forward and backward reachability analysis of the timed system, and an iterative refinement process, which produces a series of successively smaller certificates. In their experiments, model checking the certificate is several orders of magnitude faster than model checking the original system.