Re: [Cfrg] revised requirements for new curves

Eric Rescorla <ekr@rtfm.com> Fri, 12 September 2014 15:41 UTC

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From: Eric Rescorla <ekr@rtfm.com>
Date: Fri, 12 Sep 2014 08:41:10 -0700
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To: "Paterson, Kenny" <Kenny.Paterson@rhul.ac.uk>
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Subject: Re: [Cfrg] revised requirements for new curves
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On Mon, Sep 8, 2014 at 8:14 AM, Paterson, Kenny <Kenny.Paterson@rhul.ac.uk>;
wrote:

> Hi
>
> You're correct, there was not consensus on this point. The whole
> requirement is marked as [NC] on my list, meaning "no consensus". It's
> true that I did not specifically call this aspect out as being "NC".
>
> However, 192-bit security was in the initial request from TLS WG as an
> option. I don't see why we can't also solve this problem too (but I'm
> prepared to drop it if it looks like it will prevent us from making
> progress).
>

Kenny,

I suspect that this may have been a case of misplaced concreteness
on the part of the (former) chairs :)

As you say, we did ask for 128, 192 (optional), and 256-bits. In my
personal opinion
if the CFRG came back and said "we only see value in 128- and 256-bits"
that would be taken seriously.

Best,
-Ekr


> Cheers
>
> Kenny
>
> On 08/09/2014 15:42, "Phillip Hallam-Baker" <phill@hallambaker.com>; wrote:
>
> >I didn't see consensus that we needed 192 bit curves.
> >
> >These seem superfluous to me If I want speed then I will go to 128
> >bits. If I want high assurance I will go to 256. 192 is neither fish
> >nor fowl.
> >
> >In a perfect world folk can make fine tuned choices between speed and
> >security but I only have two security levels: paranoid and till the
> >sun goes supernova secure level paranoid.
>
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