Expressing Security Properties Using Selective Interleaving Functions
Source: Cornell University
McLean's notion of Selective Interleaving Functions (SIFs) is perhaps the best known attempt to construct a framework for expressing various security properties. This paper examines the expressive power of SIFs carefully. This paper shows that SIFs cannot capture Nondeducibility On Strategies (NOS). The authors also prove that the set of security properties expressed with SIFs is not closed under conjunction, from which it follows that separability is strictly stronger than double generalized noninterference. However, the authors show that if the authors generalize the notion of SIF in a natural way, then NOS is expressible, and the set of security properties expressible by generalized SIFs is closed under conjunction.