There is an increasing need within the Navy and Marine Corps for building distributed situation-aware applications that are rapidly recon gurable and survivable in the face of attacks and changing mission needs. For the Navy's vision of Network Centric Warfare and the Total Ship Computing Environment to succeed, there is an urgent need for a secure, robust, and survivable network infrastructure for disseminating mission-critical information in a timely manner. It is widely believed that intelligent software agents provide the ability to build robust, agile, and e cient distributed applications. We outline how Secure Infrastructure for Networked Systems SINS being developed at the Naval Research Laboratory will provide commanders and war ghters the necessary middleware for constructing situation-aware Command and Control C2 and combat applications. We pay particular attention to the correctness, survivability, and e ciency of the underlying middleware architecture, and develop...