Since I'm on a roll with truncated hashes: SHA2-512/384, and SHA2-512/256 are not vulnerable to a Merkle-Damgard length extension attack. Thus, a construct lik

Since I'm on a roll with truncated hashes: SHA2-512/384, and SHA2-512/256 are not vulnerable to a Merkle-Damgard length extension attack. Thus, a construct like hash(key + message) can be used similar to SHA3 [1] [1]: https://keccak.team/keccak_strengths.html https://keccak.team/keccak_strengths.html