This paper presents a secure and flexible process integration approach enabling distributed data fusion in military IoT applications. It seamlessly combines two recently developed technologies, the Dynamic Process Integration Framework and Martello, a Data Centric Security approach. The emphasis is on secure composition of heterogeneous services, corresponding to different types of algorithms as well as data sources that can be distributed over a system of networked computing nodes. The approach supports a relevant class of decision support functions that distil actionable information in environments characterized through dynamic constellations of sensors and computing services, limited communication bandwidth and stringent security requirements. Such functions contribute key elements of Information Driven Operation that can significantly improve the speed, quality and coverage of the OODA loops in challenging settings, such as Federated Mission Networks.