I am reading up on Key Deriving Functions (KDF) and in a section of the Real-World Cryptographic book by David Wong, a comparison is being made with Pseudorandom number generator (PRNG). And one of the differences is said to be that KDF takes non-uniformly random arbitrary length input, while PRN...

According to keccak strengths you have: Unlike SHA-1 and SHA-2, Keccak does not have the length-extension weakness, hence does not need the HMAC nested construction. Instead, MAC computation can be performed by simply prepending the message with the key. Meaning I can get a MAC of a message by ...