I have been with the Department of Electrical and Computer Engineering at the University of Waterloo since January 2009. For about 3 years prior, I was principal research staff in the Security and Privacy Technology Lab at Motorola Labs. I have a Ph.D. in Computer Science from Purdue University, where my advisor was Ninghui Li. Gene Spafford has also been a significant influence. Before returning to Purdue in 2003 for the Ph.D., I worked for several years, mostly in the software industry. I have a B.Sc.(Hons.) in Computer Science from Dalhousie University, where my honours project supervisor was Patrick Keast. I work in information security. Most of my research has been in access control. Recently, I have worked also on payment technologies, secure multicast and security in the context of Internet telephony. I work on both foundational (theoretical) and applied problems.