DOD Joint Vision 2020 (JV2020) is the integrated multi-service planning document for conduct among coalition forces of future warfare. It requires the confluence of a number of key avionics technical developments: integrating the network-centric battlefield, management of hundred thousands of distributed processors, high assurance Multi Level Security (MLS) in the battlefield, and low cost high assurance engineering. This paper describes the results of a study and modeling of a new security architecture, (MLS-PCA), that yields a practical solution for JV2020 based upon DARPA Polymorphic Computing Architecture (PCA) advances, and a new distributed process-level encryption scheme. The paper defines a functional model and a verified formal specification of MLS-PCA, for high assurance, with the constraints PCA software and hardware morphware must support. Also, the paper shows a viable mapping of the MLS-PCA model to the PCA hardware. MLS-PCA is designed to support upwards of 500,000 CPUs predicted by Moore's law to be available circa 2020. To test such speculation, the paper concludes with a description of an in-progress proof-of-concept implementation of MLS-PCA using a 100-node Grid Computing system and an MLS distributed targeting application.