This document describes the interface to the SecureCore operating systems (SCOS) for Phase 0 of the SecureCore project. Phase 0 is a rapid prototype with only enough specified functionality to demonstrate progress and potential capabilities of the SecureCore project. The SCOS interface includes a software emulation of the Secret-Protecting (SP) processor extensions [1]. Because this is a Phase 0 functional specification, this document is considered to be a rapid-prototype specification within a spiral life cycle model. This document is expected to change as experience is gained with the Least Privilege Separation Kernel (LPSK) environment or as better approaches are identified.NSF Grant no. CNS-0430566 and CNS-0430598 with support from DARPA AT
