On Information Flow Control in Event-B and Refinement

This paper investigates the problem of preserving information flow security in Event-B specification models and during the process of refining an abstract specification to be more concrete. A typed Event-B model is presented to enforce information flow security.We then present an approach to the problem of preserving information flow properties under abstraction refinement. The novelty of the approach is that we formalise refinement transformation in terms of the mathematical concept of Galois connection for the purpose of information-flow analysis and control. That is, the stateinvariant and state-transition predicates of the models are used to generate the Galois connection. We show how the refinement transformation ensures to preserve the security properties during the development steps from the beginning abstract-level specification to a concrete implementation.