Design of a network security policy model

The aim of this paper is to consider the development of multilevel network security policy models by drawing as many parallels as possible from the computer security models. We first consider how access control and information flow security issues arise in the design of multilevel secure network systems. We develop an outline of a simple abstract network security model which considers the access control and information flow security aspects in a multilevel network environment. We give a formal definition of such a model and the associated security requirements and then derive suitable conditions for the system to meet the security requirements. By definition, the system model is said to be 'secure' if these conditions are satisfied.