Re: NIST publishes new DSA draft

Ben Laurie <ben@algroup.co.uk> Sun, 26 March 2006 11:43 UTC

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Date: Sun, 26 Mar 2006 12:12:25 +0100
From: Ben Laurie <ben@algroup.co.uk>
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To: Jon Callas <jon@callas.org>
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Subject: Re: NIST publishes new DSA draft
References: <20060314194447.4D59A57FB0@finney.org> <20060316192823.GA9945@jabberwocky.com> <441ACF45.704@systemics.com> <87fylhdq36.fsf@wheatstone.g10code.de> <20060317174937.GC13241@jabberwocky.com> <3C3EAEDD-7724-4E92-AA3C-49B5B2E6F3F9@callas.org>
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Jon Callas wrote:
> 
> I think we ought to keep it with the same algorithm number.
> 
> I'm happy to put in SHA-224 (meaning it's trivial work), but I don't
> like it, myself. The reason is that SHA-224 is really a truncated
> SHA-256. Thus, it has no advantages over SHA-256 except being smaller by
> 32-bits with 112 bits of security. The reason it exists at all is for
> crypto-balance with 2-key 3DES (which is not TDEA), which we don't allow
> at all.

<pedantic>

3-key DES also has a strength of 112 bits.

</pedantic>

> I don't think we should have it as it goes against our
> principles of wanting a minimum of 128-bits of security in OpenPGP.
> (Yes, yes, I know that SHA-1 doesn't meet this either, but until
> SHA-256, we didn't have many options. That doesn't mean the principle is
> wrong; we *have* options.)
> 
>     Jon
> 
> 


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