Dr. Landwehr’s research in cybersecurity (earlier called computer security, information security, and information assurance) has helped a generation of researchers and practitioners understand the meaning of security in diverse systems and has led to new, more usable, access controls. Early in system security research, his results organized and advanced the field of formal models for computer security. Later, he provided an influential taxonomy for security flaws and incorporated that work with the broader field of dependable computing in a landmark paper. His publications include highly influential articles in IEEE and ACM Transactions and top tier conferences. From 2001 - 2011, he shaped research in the entire field of cybersecurity through creation and management of broad, innovative research programs at the National Science Foundation (NSF) and the Intelligence Advanced Research Projects Agency (IARPA) and through editorials in IEEE Security & Privacy Magazine.

Since retiring from his positions with the National Science Foundation (NSF) at the University of Maryland in 2011, he has worked as an independent consultant and was invited to join George Washington University’s Cyber Security and Privacy Research Institute in 2012. As a consultant, he has assisted in the development and management of a research program in the science of security, in the evaluation of programs in software engineering for the state of Israel, as a consultant to an NSF Frontier award in Trustworthy Health and Wellness, and as an advisor on research programs for several government and industry research laboratories in the U.S. and Australia. He has also developed and promoted the idea of working with industry to establish a "building code" for the construction of software with significant security requirements, organizing workshops under the auspices of the IEEE Cybersecurity Initiative and with support from the National Science Foundation to foster this idea in the domains of medical device and power system software.