Richard E. Klima is a professor in the Department of Mathematical Sciences at Appalachian State University. Prior to Appalachian State, Dr. Klima was a cryptologic mathematician at the National Security Agency. He earned a Ph.D. in applied mathematics from North Carolina State University. His research interests include cryptology, error-correcting codes, applications of linear and abstract algebra, and election theory. Neil P. Sigmon is a professor in the Department of Mathematics and Statistics at Radford University. Dr. Sigmon earned a Ph.D. in applied mathematics from North Carolina State University. His research interests include cryptology, the use of technology to illustrate mathematical concepts, and applications of linear and abstract algebra.