Argon2
A memory-hard password hashing function, winner of the 2015 Password Hashing Competition and the modern default for storing passwords.
Argon2 is a memory-hard key derivation function designed by Biryukov, Dinu, and Khovratovich, and the winner of the 2013-2015 Password Hashing Competition. It comes in three variants: Argon2d (GPU-resistant, side-channel exposed), Argon2i (side-channel resistant), and Argon2id (a hybrid, recommended for password hashing). Tuning three parameters (memory, iterations, parallelism) lets an operator force attackers to spend large amounts of RAM per guess, which crushes GPU and ASIC cracking economics. OWASP recommends Argon2id with at least 19 MiB of memory, 2 iterations, and 1 lane as a baseline for new password storage today.