This directory contains the Mathematica Notebook for the book: Introduction to Cryptography with Coding Theory, by Wade Trappe and Lawrence C. Washington. The notebook is contained in the file crypto.nb (for Mathematica 4 or earlier) crypto6.nb (for Mathematica 6 or later) The notebook contains all of the supplemental Mathematica code used in the book. To use the notebook, first download crypto.nb or crypto6.nb to a working directory or folder. (Note: If the .nb extension is not recognized by Netscape or Internet Explorer, it might be helpful to hold down the "Shift" key to download the file). Once the file has been downloaded to a working directory or folder, launch Mathematica and load the file crypto.nb or crypto6.nb . Start by evaluating the notebook (under the pull-down menu "Kernel"). We recommend then opening another notebook to perform your calculations.