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Re: MD5 To Be Considered Harmful Someday

On Tue, 7 Dec 2004, Tim wrote:

Due to the slowness of public key, most digital signatures areperformed on a digest of the original document.

I think it's time to change the way we do digital signatures tocompute several hashes of the original document using differentalgorithms (SHA1, MD5, ...) and sign the concatenation of the resultingdigests.  Does any standard signing software do this yet?Also, it's probably a good idea to alter in some small andunpredictable way anything that you're asked to sign.  (Add somespaces, add text like "Signed by David F. Skoll", etc.)  This makes itimpossible to precompute two versions that hash to the same value,though it's still not very good protection if it becomes easy to findMD5 collisions.Regards,David.

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Current thread:

• MD5 To Be Considered Harmful SomedayDan Kaminsky (Dec 07)
  • Re: MD5 To Be Considered Harmful SomedayGandalf The White (Dec 07)
    • Re: MD5 To Be Considered Harmful SomedayTim (Dec 08)
      • Re: MD5 To Be Considered Harmful SomedayDragos Ruiu (Dec 08)
      • Re: MD5 To Be Considered Harmful SomedayDavid F. Skoll (Dec 08)
    • Re: MD5 To Be Considered Harmful SomedayJoel Maslak (Dec 08)
      • Re: MD5 To Be Considered Harmful SomedaySteve Friedl (Dec 08)
    • RE: MD5 To Be Considered Harmful SomedayDavid Schwartz (Dec 08)
      • Re: MD5 To Be Considered Harmful SomedayGandalf The White (Dec 08)
      • Re: MD5 To Be Considered Harmful SomedayKeith Oxenrider (Dec 08)
      • Re: MD5 To Be Considered Harmful SomedayPaul Wouters (Dec 08)
      • Re: MD5 To Be Considered Harmful SomedayDan Kaminsky (Dec 08)
      • Re: MD5 To Be Considered Harmful SomedayPaul Wouters (Dec 08)
      • Re: MD5 To Be Considered Harmful SomedayAdam Shostack (Dec 09)
      • Re: MD5 To Be Considered Harmful SomedaySolar Designer (Dec 08)
(Thread continues...)