Making Ambients More Robust

Mobile Safe Ambients (SA) was proposed in order to remove the grave interference in the Mobile Ambient calculus. But the coactions introduced in SA also bring some security breaches. In this paper, a similar calculus called Robust Ambients (ROAM) was proposed as a more rational substitute for SA. Through specifying the parameters of the coactions, the ambients in ROAM are more robust against malicious tampering. The encoding of polyadic asynchronous π-calculus in ROAM shows that ROAM does not loss the strong expressiveness of its ancestors. The type system for ROAM proposed here also shows that the new calculus has some very good properties.