Multilevel Security
Cynthia E. Irvine · Wiley Handbook of Science and Technology for Homeland Security · 2008
Abstract Mandatory access control (MAC) policies regulate the access by users to information based upon the sensitivity level of the information and the authorization of each individual user. Multilevel secure systems provide a technical mechanism for enforcing MAC policies. Here, the background and motivation for multilevel secure systems is provided through a description of both mandatory confidentiality and mandatory integrity access control policies. Confinement is motivated and described. Supporting policies are introduced along with the notion of trusted subjects. A discussion of the criticality of multilevel mechanisms leads to design considerations and the reference monitor concept. Implementation techniques to ensure life cycle assurance are presented, including requirements for covert channel analysis. Specific technical approaches for monolithic and distributed multilevel systems are presented. Challenges associated with the development of applications able to enhance user's access to information at multiple sensitivity levels are discussed.