This is the reference C implementation of Argon2, the password-hashing
function that won the Password Hashing Competition (PHC).

Argon2 is a password-hashing function that summarizes the state of the art
in the design of memory-hard functions and can be used to hash passwords
for credential storage, key derivation, or other applications.

It has a simple design aimed at the highest memory filling rate and effective
use of multiple computing units, while still providing defense against
tradeoff attacks (by exploiting the cache and memory organization of the
recent processors).
