ni...@lysator.liu.se (Niels Möller) writes: > Simon Josefsson <si...@josefsson.org> writes: > >> I'll proceed cleaning up the Salsa code next, to reach my goal of having >> scrypt in here as well (I have it working on >> <https://www.gitorious.org/scrypt/nettle-scrypt>). > > That's the algorihtm described in > https://tools.ietf.org/html/draft-josefsson-scrypt-kdf-00, right?
Yes. > What features do you need for the salsa interface? After a quick look, > it seems you will not be processing independent blocks with salsa20, so > you will not be able to take any advantage of parallelism there (which I > imagine is an intended feature of scrypt). Right. See the patch in the last e-mail for the feature I need. > It's straight forward to add a round parameter to salsa20. But it's > still not clear to me what's the best way to support hashing only. It > would have been a bit easier if you could replace > > X = Salsa(X xor B[i]) > > by > > X = Salsa(X) xor B[i] > > since the latter is closer to the standard encryption operation. I think > the iteration *can* be rewritten in that form by some change of > variables, but you'd need an extra xor at the end to really get Y[i] > rather than Y[i] xor B[i]. The algorithm specification is already set in > stone? Setting it stone is my goal. Scrypt has been in use for around 3 years and is implemented in several languages. Admittedly, several people (including myself) have ideas about various tweaks to the algorithm that may improve it, but I believe it is better for those ideas to be described separately under a different name. It would be extremely confusing for "scrypt" to mean anything but the algorithm described in the original paper. /Simon _______________________________________________ nettle-bugs mailing list nettle-bugs@lists.lysator.liu.se http://lists.lysator.liu.se/mailman/listinfo/nettle-bugs
