On this question https://stackoverflow.com/questions/5889238/why-is-xor-the-default-way-to-combine-hashes a couple of the answers say that xoring is a bad/insecure choice for combining hashes. However, most of them say that in regards to xoring two identical hashes.
If I want to combine a Keccak-256, Skein-256-256, Blake2b-256, and Groestl-256 hash, would it be more secure to concatenate parts of the hash, or to xor the hashes together?
[(hash_id, hash(message))]
, a list of hashes with a per-hash-function identifier. $\endgroup$ – cypherfox May 9 '18 at 9:02