Multi-Level Security with UNIX(R) System V/MLS

System V/Multi-Level Security (MLS) was developed at AT&T to address the needs of its government customers. It makes use of enhanced security features, mandatory access controls, data labeling, and audit trails to provide a secure environment for government applications that require different levels of protection yet must reside on the same computer. This gives the background behind the development of System V/MLS, discuss the Department of Defense (Dod) criteria that must be satisfied to achieve a certain rating, and describes the features and current porting status of System V/MLS.