Key Derivation: PBKDF2 & HKDF
Derives cryptographic keys two ways: PBKDF2 stretches a low-entropy password into a key using a salt and a high iteration count, while HKDF expands existing high-entropy key material into one or more subkeys. Shows the derived bytes in hex and Base64 with your chosen hash, salt, info and length.
Runs 100% in your browser — keys and data never leave your device.
Read the full guide to this tool
Notes
- PBKDF2 is for passwords: the salt stops rainbow tables and the iteration count slows brute force. Use hundreds of thousands of iterations for SHA-256.
- HKDF is not for passwords — it assumes the input is already high-entropy (e.g. an ECDH shared secret) and is cheap by design.
- Runs 100% in your browser — keys and data never leave your device.
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