Colored Petri Net based model checking and failure analysis for E-commerce protocols

We present a Colored Petri Net approach to model check three atomicity properties for the NetBill electronic cash system. We verify that the protocol satisfies money atomicity, goods atomicity and certified delivery in the presence of potential site or communication failures and all possible unilateral transaction abort cases. Model checking is performed in CPN Tools, a graphical ML-based tool for editing and analyzing Colored Petri Nets (CP-nets). In case of property violation, protocol failure analysis aims in exploring all property violation scenarios, in order to correct the protocol’s design. Model checking exploits the provided state space exploration functions and the supported Computation Tree like temporal logic (CTL). On the other hand, protocol failure analysis is performed by inspection of appropriately selected markings and if necessary, by interactively simulating certain property violation scenarios. In ecommerce, Colored Petri Net model checking has been used in verifying absence of deadlocks, absence of livelocks and absence of unexpected dead transitions, as well as in verifying a protocol against its service. To the best of our knowledge, our work is the first attempt to employ CP-nets for model checking atomicity properties. We believe that the described approach can also be applied in model checking other functional properties that are not directly related to the structural properties of the generated state space graph.