Re: NIST publishes new DSA draft

Ben Laurie <ben@algroup.co.uk> Wed, 15 March 2006 12:22 UTC

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Date: Wed, 15 Mar 2006 11:57:15 +0000
From: Ben Laurie <ben@algroup.co.uk>
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To: Hal Finney <hal@finney.org>
CC: james.couzens@electricmail.com, ietf-openpgp@imc.org
Subject: Re: NIST publishes new DSA draft
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Hal Finney wrote:
> James Couzens writes:
>> I had thought it a bit strange that someone writing so comprehensively
>> about something related to digital signatures and to then make the
>> statement as you did at the end of the paragraph I quoted.  Did you have
>> some other intended meaning, such as broken by draft explicit
>> prohibition or otherwise declared deprecated in a future draft?
> 
> Yes, sorry, my language was not as precise as it might have been.
> I said we should be ready in case SHA-1 were broken, but as you note
> it has been officially "broken" for over a year.  However that is just
> a theoretical break and no actual examples of SHA-1 message collisions
> have yet been published.  So at this point SHA-1 is in a bit of a limbo
> state, theoretically broken but still in widespread use.

Its also worth noting that reducing the collision resistance to 2^69
still leaves it stronger than unbroken MD5 and is still well within the
realms of hardness we require.

Cheers,

Ben.

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