A hookup theorem for multilevel security
Daryl McCullough · IEEE Transactions on Software Engineering · 1990
A security property for trusted multilevel systems, restrictiveness, is described. It restricts the inferences a user can make about sensitive information. This property is a hookup property, or composable, meaning that a collection of secure restrictive systems when hooked together form a secure restrictive composite system. It is argued that the inference control and composability of restrictiveness make it an attractive choice for a security policy on trusted systems and processes.>