On Wed, Dec 5, 2012 at 11:19 AM, Sebastian Schuberth <sschube...@gmail.com> wrote: > to say it in advance: I do not want to trigger any bogus security discussion > here. Instead, I believe the findings from [1] allow for an up to 20% faster > SHA1 calculation, if my brief reading of the presentation is correct. Any > opinions on integration this optimization into Git? > > [1] https://hashcat.net/p12/js-sha1exp_169.pdf
Pretty cool find. Although it's not actual cryptographic weakness, it does show some gaps in designers thinking - as there are simple optimizations available to crackers but not users. It does seem unusable for real implementation - the 20% win is available only after the data is processed properly once. Then after changing the data a little, you can calculate next hash faster. There still small possibility that there is way to optimize W calculation for the first run, but it does seem really hard, and even impossible while trying to keep the cache usage small. -- marko -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
