I believe such code can be tested in practice with great confidence. If I would test such kind of code, I would replace the SHA256 code with a rogue version that emits equal hashes for certain bit patterns.
As a side note, I also don't trust my macbook's 16 gig of internal computer memory - there is a (rather big) chance that bit-errors will silently corrupt state. Even EEC memory suffers that fate (but of course with a much lower chance). It is impossible to build a system that achieves 100% data correctness: SHA256 will do fine for now. On Sep 27, 2013, at 4:37 PM, David Barbour <dmbarb...@gmail.com> wrote: > The usual problem with this sort of "handle this super-rare event when it > happens" code is that it is poorly tested in practice. Should you trust it? > > > On Thu, Sep 26, 2013 at 11:46 PM, Robbert van Dalen > <robbert.van.da...@gmail.com> wrote: > Hi, > > ZFS has de-duplication built on top of SHA256 hashes. > If the verify option is also enabled, it is possible for ZFS to work around > detect hash collisions (although this option slows things down further). > > But ZFS can be considered as a kind of 'central authority' so its > de-duplication scheme may not work in a distributed setting. > > Regards, > Robbert. > > On Sep 27, 2013, at 2:50 AM, Wolfgang Eder <e...@generalmagic.at> wrote: > > > hi, > > in recent discussions on this list, the idea of using hashes to > > identify or even name things is often mentioned. > > in this context, hashes are treated as being unique; > > > > albeit unlikely, it *is* possible that hashes are equal > > for two distinct things. are there ideas about > > how to handle such a situation? > > > > thanks and kind regards > > wolfgang > > _______________________________________________ > > fonc mailing list > > fonc@vpri.org > > http://vpri.org/mailman/listinfo/fonc > > _______________________________________________ > fonc mailing list > fonc@vpri.org > http://vpri.org/mailman/listinfo/fonc > > _______________________________________________ > fonc mailing list > fonc@vpri.org > http://vpri.org/mailman/listinfo/fonc _______________________________________________ fonc mailing list fonc@vpri.org http://vpri.org/mailman/listinfo/fonc
