Battlefield monitoring involves collecting streaming data from different sources, transmitting the data over a
heterogeneous network, and processing queries in real-time in order to respond to events in a timely manner.
Nodes in these networks differ with respect to their trustworthiness, processing, storage, and communication
capabilities. Links in the network differ with respect to their communication bandwidth. The topology of the
network itself is subject to change, as the nodes and links may become unavailable. Continuous queries executed
in such environments must also meet some quality of service (QoS) requirements, such as, response time and
throughput. Data streams generated from the various nodes in the network belong to different security levels;
consequently, these must be processed in a secure manner without causing unauthorized leakage or modification.
Towards this end, we demonstrate how an existing complex event processing system can be extended to execute
queries and events in a secure manner in such a dynamic and heterogeneous environment.