We’re releasing SequenceHash and its sister function SequenceMAC, a pair of related hash constructions that bring secure multihashing to developers using hash functions other than Keccak.
HKDF is really two functions, HKDF-Extract and HKDF-Expand. If you already have a uniform random key then you can skip the first and just use the latter, removing the need for a salt.
If you are using SHA-256 and are happy with 128-bit security then this boils down to:
Does HKDF needs a random number generator for the salt? I wonder if there’s a way to define your cascade such that it’s generic and deterministic.
score 1 · canonical
HKDF is really two functions, HKDF-Extract and HKDF-Expand. If you already have a uniform random key then you can skip the first and just use the latter, removing the need for a salt.
If you are using SHA-256 and are happy with 128-bit security then this boils down to:
Where “some context” is eg a fixed string like “my-app-cascade-mac-subkeys” or whatever.
score 1 · canonical