On Sat, 21 Jul 2018 23:59:41 +0000, brian m. carlson wrote: > On Sun, Jul 22, 2018 at 12:38:41AM +0200, Johannes Schindelin wrote: > > Do you really want to value contributors' opinion more than > > cryptographers'? I mean, that's exactly what got us into this hard-coded > > SHA-1 mess in the first place. > > I agree (believe me, of all people, I agree) that hard-coding SHA-1 was > a bad choice in retrospect. But I've solicited contributors' opinions > because the Git Project needs to make a decision *for this project* > about the algorithm we're going to use going forward. > > > And to set the record straight: I do not have a strong preference of the > > hash algorithm. But cryprographers I have the incredible luck to have > > access to, by virtue of being a colleague, did mention their preference. > > I don't know your colleagues, and they haven't commented here. One > person that has commented here is Adam Langley. It is my impression > (and anyone is free to correct me if I'm incorrect) that he is indeed a > cryptographer. To quote him[0]: > > I think this group can safely assume that SHA-256, SHA-512, BLAKE2, > K12, etc are all secure to the extent that I don't believe that making > comparisons between them on that axis is meaningful. Thus I think the > question is primarily concerned with performance and implementation > availability. > > […] > > So, overall, none of these choices should obviously be excluded. The > considerations at this point are not cryptographic and the tradeoff > between implementation ease and performance is one that the git > community would have to make. Am I completely out of the game, or the statement that "the considerations at this point are not cryptographic" is just the wrongest ? I mean, if that was true, would we not be sticking to SHA1 ? > I'm aware that cryptographers tend to prefer algorithms that have been > studied longer over ones that have been studied less. They also prefer > algorithms built in the open to ones developed behind closed doors. > > SHA-256 has the benefit that it has been studied for a long time, but it > was also designed in secret by the NSA. SHA3-256 was created with > significant study in the open, but is not as mature. BLAKE2b has been > incorporated into standards like Argon2, but has been weakened slightly > for performance. > > I'm not sure that there's a really obvious choice here. > > I'm at the point where to continue the work that I'm doing, I need to > make a decision. I'm happy to follow the consensus if there is one, but > it does not appear that there is. > > I will admit that I don't love making this decision by myself, because > right now, whatever I pick, somebody is going to be unhappy. I want to > state, unambiguously, that I'm trying to make a decision that is in the > interests of the Git Project, the community, and our users. > > I'm happy to wait a few more days to see if a consensus develops; if so, > I'll follow it. If we haven't come to one by, say, Wednesday, I'll make > a decision and write my patches accordingly. The community is free, as > always, to reject my patches if taking them is not in the interest of > the project. > > [0] https://public-inbox.org/git/CAL9PXLzhPyE+geUdcLmd=pidT5P8eFEBbSgX_dS88knz2q_LSw@mail.gmail.com/ > -- > brian m. carlson: Houston, Texas, US > OpenPGP: https://keybase.io/bk2204 -- Eric Deplagne