# 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