Hello,
while writing some articles about dedup, hashes and ZFS for my blog, i asked
myself: When fletcher4 is fast, but collision prone and sha256 is slower, but
relatively secure, wouldn''t it be reasonable to integrate Skein
(http://www.schneier.com/skein.pdf) into ZFS to yield faster checksumming as
well as a reduced probability of false positive deduplications due to hash
collisions?
Regards
Joerg
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On 07/02/2010 20:07, Joerg Moellenkamp wrote:> Hello, > > while writing some articles about dedup, hashes and ZFS for my blog, i > asked myself: When fletcher4 is fast, but collision prone and sha256 is > slower, but relatively secure, wouldn''t it be reasonable to integrate > Skein (http://www.schneier.com/skein.pdf) into ZFS to yield faster > checksumming as well as a reduced probability of false positive > deduplications due to hash collisions?If Skein passes the cryptanlaysis for the SHA3 competition being run by NIST and is the winner of that competition or is otherwise considered sounds by the crypto community then yes until then I think it is premature to do so as it is a very new algorithm. -- Darren J Moffat
On Feb 7, 2010, at 15:10, Darren J Moffat wrote:> On 07/02/2010 20:07, Joerg Moellenkamp wrote: >> Hello, >> >> while writing some articles about dedup, hashes and ZFS for my >> blog, i >> asked myself: When fletcher4 is fast, but collision prone and >> sha256 is >> slower, but relatively secure, wouldn''t it be reasonable to integrate >> Skein (http://www.schneier.com/skein.pdf) into ZFS to yield faster >> checksumming as well as a reduced probability of false positive >> deduplications due to hash collisions? > > If Skein passes the cryptanlaysis for the SHA3 competition being run > by NIST and is the winner of that competition or is otherwise > considered sounds by the crypto community then yes until then I > think it is premature to do so as it is a very new algorithm.A new attack on Threefish (which Skein is based on) was recently announced: http://www.schneier.com/blog/archives/2010/02/new_attack_on_t.html Any reason why the OP prefers Skein over any of the other SHA-3 candidates? http://en.wikipedia.org/wiki/NIST_hash_function_competition
Well, it''s an attack, right? Neither Skein nor Threefish has been compromised. In fact, this is what you want to see - researchers attacking an algorithm which goes a long way toward furthering or proving the security of said algorithm. I think I agree with Darren overall, but this still looks promising because these researchers, while attacking Threefish and clearly finding some way to simplify a further attack, have still not managed to compromise it. Exposing the algo to the scrutiny of the community will either help strengthen it, or expose its weakness, and all will be better as a result (in theory). I am now curious, though, along with David, as to the reason Skein in particular was pointed out? Is there any particular reason, or is it just that Joerg came across it while working on his blog posts? There may not be a reason, which is perfectly fine, but for the sake of curiosity, if there is one, please share Joerg. On Sun, Feb 7, 2010 at 15:53, David Magda <dmagda at ee.ryerson.ca> wrote:> > On Feb 7, 2010, at 15:10, Darren J Moffat wrote: > > On 07/02/2010 20:07, Joerg Moellenkamp wrote: >> >>> Hello, >>> >>> while writing some articles about dedup, hashes and ZFS for my blog, i >>> asked myself: When fletcher4 is fast, but collision prone and sha256 is >>> slower, but relatively secure, wouldn''t it be reasonable to integrate >>> Skein (http://www.schneier.com/skein.pdf) into ZFS to yield faster >>> checksumming as well as a reduced probability of false positive >>> deduplications due to hash collisions? >>> >> >> If Skein passes the cryptanlaysis for the SHA3 competition being run by >> NIST and is the winner of that competition or is otherwise considered sounds >> by the crypto community then yes until then I think it is premature to do so >> as it is a very new algorithm. >> > > A new attack on Threefish (which Skein is based on) was recently announced: > > http://www.schneier.com/blog/archives/2010/02/new_attack_on_t.html > > Any reason why the OP prefers Skein over any of the other SHA-3 candidates? > > http://en.wikipedia.org/wiki/NIST_hash_function_competition > > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >-- "You can choose your friends, you can choose the deals." - Equity Private "If Linux is faster, it''s a Solaris bug." - Phil Harman Blog - http://whatderass.blogspot.com/ Twitter - @khyron4eva -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.opensolaris.org/pipermail/zfs-discuss/attachments/20100207/55e71307/attachment.html>