Design of a network security policy model

The paper considers the development of multilevel network security policy models by drawing as many parallels as possible from computer security models. It first considers how access control and information flow security issues arise in the design of multilevel secure network systems. It discusses these issues using typical scenarios, then develops an outline of a simple abstract network security model which considers the access control and information flow security aspects in a multilevel network environment. A formal definition of such a model and the associated security requirements is given, then suitable conditions are derived for the system to meet the security requirements.