Argon2
A memory-hard password hashing function and the winner of the Password Hashing Competition (RFC 9106). Use the Argon2id variant; OWASP’s minimum is 19 MiB of memory, 2 iterations and 1 degree of parallelism, with a unique salt for each password.
- Also called
- Argon2id
- Defined in
- RFC 9106
Covered in
Password storage: hashing parameters and rehash on login
Choose Argon2id, scrypt, PBKDF2 or bcrypt with current minimum parameters, store a versioned hash, and upgrade old hashes after a successful login without overwriting a reset.
Choose cryptographic algorithms and parameters by job
A sourced quick reference for October 2026: which algorithm and parameters to use for encryption, hashing, passwords, MACs, signatures, key agreement, key derivation, randomness and TLS, the matching APIs in Node.js, Python, Java, Go and .NET, and where post-quantum migration stands.
Practice: Insecure randomness lab: Generate unguessable API keys · Password hashing lab: Verify and upgrade an Argon2 password hash on login