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. On Unix systems, the "crypt" module may also be
available. Here’s an overview:

* 15.1. "hashlib" — Secure hashes and message digests

  * 15.1.1. Hash algorithms

  * 15.1.2. Key derivation

* 15.2. "hmac" — Keyed-Hashing for Message Authentication
