Abstract : The specific aims of this research is to develop theories, methodologies, tools, and implementable solutions for modeling, analyzing, designing, and securing information networks against information-based attack. Accomplishments during the current reporting period are documented in 49 publications and 1 patent application and include: New methods for the optimization of complex systems; simulation-based methods for real-time decision making; proof-of-concept implementations of solutions for malware spreading and wireless data-link security; a feedback control approach for defense against DDoS; randomized protocols for managing the performance vs. security trade-off in wireless networks; automated Red Teaming tools and intrusion traceback methods for mobile ad-hoc wireless networks; a new dynamic Bayesian network based approach for detection and estimation in networked environments; and an adaptive defense architecture for fast spreading internet worms. Plans for the coming year will focus on further exploration of optimization, feedback and randomness in security; continued development of methods for security assessment, particularly in wireless settings; completion of the dynamic Bayesian framework for detection and estimation in networks; and a continued exploration of vulnerabilities and methods for military enterprise networks. These efforts will contribute new understanding and new approaches for securing and managing distributed, decentralized command and control systems.