Stephen Yoo is a Ph.D student in Nuclear and Radiological Engineering, George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology. He recieved B.E. and M.E. degrees in Nuclear Engineering, Kyung Hee University, Korea. His research interests are in safety and security of nuclear facilities, including analog/digital instrumentation and control (I&C) systems, safety assessment, and cybersecurity issues arising from digital I&C systems. His recent research covers developing cyber-physical protection systems for molten salt reactors (MSRs).