Enriching the Expressive Power of Security Labels

|Common security models such as Bell-LaPadula focus on the control of access to sensitive data but leave some important systems issues unspeciied, such as the implementation of read-only objects, garbage collection, and object upgrade and downgrade paths. Consequently, diier-ent implementations of the same security model may have connicting operational and security semantics. We propose the use of more expressive security labels for specifying these system issues within the security model, so that the semantics of a system design are precisely understood and are independent of implementation details.