Douglas R. Stinson obtained his PhD in Combinatorics and Optimization from the University of Waterloo in 1981. He held academic positions at the University of Manitoba and the University of Nebraska-Lincoln before returning to Waterloo in 1998, when he was awarded the NSERC/Certicom Industrial Research Chair in Cryptography. Dr. Stinson currently holds the position of University Professor in the David R. Cheriton School of Computer Science at the University of Waterloo. His research interests include cryptography and computer security, combinatorics and coding theory, and applications of discrete mathematics in computer science. He was elected as a Fellow of the Royal Society of Canada in 2011. Maura Paterson obtained a PhD in Mathematics from Royal Holloway, University of London in 2005. Her research focuses on applications of combinatorics in information security and related areas. She is a Reader in Mathematics in the Department of Economics, Mathematics and Statistics at Birkbeck, University of London.