A multilevel security policy model for networks

Consideration is given to the development of security policy models for networks which can operate in a multilevel security environment. An outline is presented of an abstract security policy model which addresses the access-control and information-flow requirements in a multilevel network. The network security policy is formulated by drawing as much parallel as possible with the computer security policy. The model is defined, and the associated security requirements are given. The model is used to prove that the security conditions are not violated by the defined network operations.