There are two versions of LUKS, with LUKS2 having features such as resilience to header corruption, and using the Argon2 key derivation function by default, whereas LUKS1 uses PBKDF2. Conversion between both versions of LUKS is possible in certain situations, but some features may not be available with LUKS1 such as Argon2. LUKS2 uses JSON as a metadata format.
