An implementation of MLS on a network of workstations using X.500/509

We describe a project whose goal is to provide a secure distributed access control mechanism for user tasks in a heterogeneous network of computing resources. This is accomplished by implementing a UNIX-based multi-level security (MLS) scheme where users and resources are labeled with a security level and a group. Access control is enforced by an access list server that uses X.500 directory and X.509 authentication services. Groundwork is laid for the next step of the project, which is to extend the security services for migrating tasks so that workstations are protected from security threats posed by incoming tasks, and also to protect tasks from threats originating from the workstation