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15. Cryptographic Services

The modules described in this chapter implement various algorithms of a cryptographic nature. They are available at the discretion of the installation. Here's an overview:

`hmac` |  | Keyed-Hashing for Message Authentication (HMAC) implementation for Python.
`md5` |  | RSA's MD5 message digest algorithm.
`sha` |  | NIST's secure hash algorithm, SHA.
`mpz` |  | Interface to the GNU MP library for arbitrary precision arithmetic.
`rotor` |  | Enigma-like encryption and decryption.

Hardcore cypherpunks will probably find the cryptographic modules written by A.M. Kuchling of further interest; the package adds built-in modules for DES and IDEA encryption, provides a Python module for reading and decrypting PGP files, and then some. These modules are not distributed with Python but available separately. See the URL http://www.amk.ca/python/code/crypto.html for more information.