OptionalencodeOptionaliterationsLegacy hashes only: PBKDF2 iterations they were made with. Default 250000 (crypto-js 4.2.0).
OptionalkeyLegacy hashes only: derived key length in 32-bit words. Default 4 (16 bytes, crypto-js 4.2.0).
OptionalsecretOptional pepper. New hashes mix it into the salt when it is set; legacy hashes were made with String(secret).
Legacy hashes only: they are base64 of the hex text.