Towards a behavioural theory of access and mobility control in distributed systems

We define a typed bisimulation equivalence for the language DPI, a distributed version of the pi-calculus in which processes may migrate between dynamically created locations. It takes into account resource access policies, which can be implemented in DPI using a novel form of dynamic capability types. The equivalence, based on typed actions between configurations, is justified by showing that it is fully abstract with respect to a natural distributed version of a contextual equivalence. In the second part of the paper we study the effect of controlling the migration of processes. This affects the ability to perform observations at specific locations, as the observer may be denied access. We show how the typed actions can be modified to take this into account, and generalise the full-abstraction result to this more delicate scenario. (C) 2003 Published by Elsevier B.V.