Enforcing Generalized Refinement-Based Noninterference for Secure Interface Composition

Information flow security has been considered as a critical requirement on complicated component-based software. The recent efforts on the compositional information flow analyses were limited on the expressiveness of security lattice and the efficiency of compositional enforcement. Extending these approaches to support more general security lattices is usually nontrivial because the compositionality of information flow security properties should be properly treated. In this work, we present a new extension of interface automaton. On this interface structure, we propose two refinement-based security properties, adaptable to any finite security lattice. For each property, we present and prove the security condition that ensures the property to be preserved under composition. Furthermore, we implement the refinement algorithms and the security condition decision procedure. We demonstrate the usability and efficiency of our approach with in-depth case studies. The evaluation results show that our compositional enforcement can effectively reduce the verification cost compared with global verification on composite system.