Derive cryptographic keys from passwords

Derive a cryptographic key from a password with PBKDF2.

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ToolPBKDF2 Key Derivation
Input
Output
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How it works

PBKDF2 applies a pseudorandom function to a password, salt, block counter, and iteration count, XORing each repeated output into a derived block. Blocks are concatenated and truncated to the requested key length.

  • A random salt separates equal passwords while iterations raise offline cost.

Worked example

Derive Key
Derive a 256-bit key from a password and salt using PBKDF2
Input
											Input: MyPassword123
Salt: random-salt-value
Output
												e2149a2848050420eb689215a0cdc6b46805389a0771d93c1724d81552700fbf

When to use this

Password-based encryption, legacy file formats, and iteration upgrades derive keys with PBKDF2.

Edge cases

  • Reusing a salt makes equal passwords comparable.
  • Changing the iteration count changes the derived key.
  • A short password remains weak despite many iterations.

References