books.google.com - Discrete mathematics is quickly becoming one of the most important areas of mathematical research, with applications to cryptography, linear programming, coding theory and the theory of computing. This book is aimed at undergraduate mathematics and computer science students interested in developing a...http://books.google.com/books/about/Discrete_Mathematics.html?id=rzwn7g0PCooC&q=one-time+pad&utm_source=gb-gplus-shareDiscrete Mathematics