I'm not sure how to word this... I'm working with a HMAC (I think of it being a "salted hash"). I know the entire string being hashed, I do NOT know the salt. I also know the first 8 characters of the resulting hash. I can also, repeatedly, generate new hashes by changing the input string, and retrieve new first-8 characters.
Does that in any way make it even remotely possible to find the salt? Even via brute forcing, would that decrease the entropy at all, if I were able to modify the hashing algo (much like how bitcoin is mined by pre-computing most of the hash and only updating the nonce at the end, removing many many steps from the hashing itself)?
From all I've learned, I'm leaning towards a "no", that its no help whatsoever. That being said, I've never worked with a HMAC/salted hash before, so I'm not sure if that works any differently. Is finding the salt any easier because of how a HMAC is computed?