I. Introduction
Key derivation functions (KDFs) have been around for decades now. Their purpose resides in deriving strong cryptographic keys from pieces of information which may not have a good level of randomness, e.g. passwords. Being part of RSA Laboratories' Public-Key Cryptography Standards series (PKCS), versions of the Password-Based Key Derivation Function (PBKDF) were recommended as the de facto standard for password hashing [1] [2].