1. M. Gardner, Codes, Ciphers, and Secret Writing. Dover Publications, Inc. New York 1984.
  2. A. Young, Mathematical Ciphers: From Caesar to RSA. Mathematical World, Volume 25. American Mathematical Society 2006.

Number Theory

  1. I. Niven, H. Zuckerman, and H. Montgomery, An Introduction to the Theory of Numbers, 5th ed. Wiley 1991
  2. K. Rosen, Elementary Number Theory, 5th ed. Addison Wesley 2004.

This work was made possible through a grant from the National Science Foundation.