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Re: Re: SHA1 hash safety

From
Petr Baudis <pasky@ucw.cz>
Date
Apr 16, 2005, 15:11 UTC
Message-ID
<20050416151116.GC19099@pasky.ji.cz>
In-Reply-To
<Pine.LNX.4.61.0504161040310.29343@cag.csail.mit.edu>

Dear diary, on Sat, Apr 16, 2005 at 04:58:15PM CEST, I got a letter where "C. Scott Ananian" <cscott@cscott.net> told me that...

Show 21 quoted lines
> On Sat, 16 Apr 2005, Brian O'Mahoney wrote:
> 
> >(1) I _have_ seen real-life collisions with MD5, in the context of
> >   Document management systems containing ~10^6 ms-WORD documents.
> 
> Dude!  You could have been *famous*!  Why the 
> aitch-ee-double-hockey-sticks didn't you publish this when you found it?
> Seriously, man.
> 
> Even given the known weaknesses in MD5, it would take much more than a 
> million documents to find MD5 collisions.  I can only conclude that the 
> hash was being used incorrectly; most likely truncated (my wild-ass guess 
> would be to 32 bits; a collision is likely with > 50% probability in a 
> million document store for a hash of less than 40 bits).
> 
> I know the current state of the art here.  It's going to take more than 
> just hearsay to convince me that full 128-bit MD5 collisions are likely. 
> I believe there are only two or so known to exist so far, and those were 
> found by a research team in China (which, yes, is fairly famous among the 
> cryptographic community now after publishing a paper consisting of little 
> apart from the two collisions themselves).
http://cryptography.hyperlink.cz/MD5_collisions.html
-- 
				Petr "Pasky" Baudis
Stuff: http://pasky.or.cz/
C++: an octopus made by nailing extra legs onto a dog. -- Steve Taylor
Previous: C. Scott AnanianNext: C. Scott Ananian
Message 6 of 30 in “SHA1 hash safety”
  1. David LangApr 16, 2005
  2. Ingo MolnarApr 16, 2005
  3. David LangApr 16, 2005
  4. Brian O'MahoneyApr 16, 2005
  5. C. Scott AnanianApr 16, 2005
  6. Petr BaudisApr 16, 2005
  7. C. Scott AnanianApr 16, 2005
  8. David LangApr 16, 2005
  9. Paul JacksonApr 16, 2005
  10. Martin MaresApr 16, 2005
  11. David A. WheelerApr 17, 2005
  12. Theodore Ts'oApr 18, 2005
  13. ross@lug.udel.eduApr 16, 2005
  14. Horst von BrandApr 17, 2005
  15. Brian O'MahoneyApr 18, 2005
  16. C. Scott AnanianApr 18, 2005
  17. Paul JacksonApr 16, 2005
  18. Brian O'MahoneyApr 16, 2005
  19. Andy IsaacsonApr 18, 2005
  20. C. Scott AnanianApr 18, 2005
  21. David MeybohmApr 19, 2005
  22. C. Scott AnanianApr 19, 2005
  23. David MeybohmApr 20, 2005
  24. David LangApr 16, 2005
  25. Paul JacksonApr 16, 2005
  26. David LangApr 16, 2005
  27. TkilApr 17, 2005
  28. Paul JacksonApr 17, 2005
  29. TkilApr 17, 2005
  30. Paul JacksonApr 17, 2005

Read the whole thread, see it on lore, or plain text.

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