Extending theNoninterference Versionof MLS

A noninterference formulation ofMLS applicable tothe Secure AdanTarget (SAT)Abstract Modelisdeveloped. Ananalogous formulation isdeveloped tohandle theSATtypeenforcement policy. Unwinding theorems arepresented forbothMLS andMultidomain Security (MDS)andtheSATAbstract Modelisshowntosatisfy both MLS andMDS.Generalizations andextensions arealso considered. Index Terms-Access control, assured pipeline, covert channel anal- ysis, multilevel security, noninterference, security policy model, type enforcement.