This document discusses PHP 7.2's inclusion of the cryptography library Libsodium and the password hashing algorithm Argon2. It provides an overview of Libsodium, describing it as a high-speed cryptography library that implements modern cryptographic standards, including authenticated encryption and public-key cryptography. It then demonstrates how to use Libsodium and Argon2 in PHP 7.2 for password hashing, generic hashing, secret-key encryption, and public-key encryption.