# LUKS multiple key slots - what's the intuition?

The intuition behind basic encryption with a single key is pretty straightforward.

ciphertext = BIG_FUNCTION(plaintext, key)
plaintext = BIG_FUNCTION^(-1)(ciphertext, key)


Can anyone explain how a LUKS volume can permit independently usable passwords? I'm just looking for the intuition - not necessarily a detailed explanation of how LUKS in particular handles this.

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Roughly your password is used to encrypt a MasterSecretKey. Then you use this MasterSecretKey with a symmetric algorithm to encrypt or decrypt your data (the disk sectors). They eight key slots in LUKS are eight different encryptions of the same MasterSecretKey under eight different passwords.