\chapter{CRYPTOGRAPHIC EXTENSIONS} The modules described in this chapter implement various algorithms of a cryptographic nature. They are available at the discretion of the installation. \index{cryptography} Hardcore cypherpunks will probably find the Python Cryptography Kit of further interest; the package adds built-in modules for DES and IDEA encryption, and provides a Python module for reading and decrypting PGP files. The Python Cryptography Kit is not distributed with Python but available separately. See the URL \file{http://www.cs.mcgill.ca/\%7Efnord/crypt.html} for more information. \index{PGP} \indexii{DES}{cipher} \indexii{IDEA}{cipher} \index{Python Cryptography Kit}