Kris Gaj is an Assistant Professor in the Department of Electrical and Computer Engineering at George Mason University since August 1998. He received the M.S. and Ph.D. degrees in Electrical and Computer Engineering from Warsaw University of Technology, Poland, in 1988 and 1992, respectively.

He has worked in computer-network security, computer arithmetic, testing of integrated circuits, and VLSI design automation. In 1991, he was a visiting scholar in the School of Computing Science at the Simon Fraser University in Vancouver, Canada, where he worked on the analysis of various BIST (build-in self-test) techniques for VLSI digital circuits. In 1992-93, he headed a research team at the Warsaw University of Technology developing an implementation of the Internet standard for secure electronic mail (Privacy Enhanced Mail), and software for secure Electronic Data Interchange per UNO standard UN-EDIFACT. He was a founder of ENIGMA, a company that generates practical software and hardware applications from new cryptographic research. In 1994-98, he was with the Department of Electrical Engineering at the University of Rochester, Rochester, NY, where he where he worked on logic level design and timing analysis of  high-speed digital circuits.

His current research interests include cryptography, computer arithmetic, CAD tools, testing, and hardware/software co-design. He is the author of a book on breaking German machine cipher ENIGMA.