On Information Flow Control in Event-B and Refinement

This paper investigates the problem of preservinginformation flow security in Event-B specification models andduring the process of refining an abstract specification tobe more concrete. A typed Event-B model is presented toenforce information flow security. We then present an approachto the problem of preserving information flow propertiesunder abstraction refinement. The novelty of the approach isthat we formalise refinement transformation in terms of themathematical concept of Galois connection for the purposeof information-flow analysis and control. That is, the state-invariant and state-transition predicates of the models areused to generate the Galois connection. We show how therefinement transformation ensures to preserve the securityproperties during the development steps from the beginningabstract-level specification to a concrete implementation