Compare PBKDF2, HKDF and common password-KDF considerations.
| Item | Value | Guidance |
|---|---|---|
| PBKDF2 | Password-derived keys | Salt + iterations + PRF; broadly available. |
| HKDF | High-entropy key material | Designed for key expansion/extraction, not low-entropy passwords. |
| Argon2id | Password hashing/KDF | Memory-hard and preferred for new password storage. |
| scrypt | Password hashing/KDF | Memory-hard alternative when appropriate. |
Review the available algorithms, properties, key sizes, compatibility notes, and recommended use cases shown on the page. Match the guidance to your protocol, threat model, and current platform support rather than selecting an algorithm by name alone.
The cryptography result or reference describes the encoding, key, digest, entropy, or algorithm selected and the input supplied. Encoding is not encryption, and a generated value is only as secure as the randomness, implementation, and handling behind it.
Use this for learning, format conversion, or preliminary cryptographic planning. Verify algorithms and key sizes against current security guidance; never expose private keys, production secrets, or live credentials in an untrusted tool.