The primary goals of the STEG (Secure Tactical-Enterprise Gateway) project were to develop, demonstrate and evaluate the technical underpinnings required to enable information dissemination from tactical to enterprise environments and vice versa, without compromising the security of either side and without overwhelming the limited resources of the tactical network. Specifically, the STEG project researched the requirements motivating the cross-environment IMS interaction, analyzed the fundamental differences between the tactical and enterprise environments, designed and implemented a gateway solution that leverages prior AFRL investment in advanced protection and Quality of Service (QoS) management technologies, and performed experimental evaluation and logical analysis of the resulting STEG prototype.