Re: [TLS] Re-thinking OPTLS

Martin Thomson <> Sat, 22 November 2014 06:14 UTC

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Date: Fri, 21 Nov 2014 20:14:55 -1000
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From: Martin Thomson <>
To: Hugo Krawczyk <>
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Cc: "" <>, Hoeteck Wee <>
Subject: Re: [TLS] Re-thinking OPTLS
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On 21 November 2014 19:29, Hugo Krawczyk <> wrote:
> I am glad to hear this too. Please let me know what the sources of perceived
> complexity are.

The only items of note were:
 - the second update to the handshake protection under g^{xs}+g^{xy}.
We all realized that this was trivially addressed (ekr had a slide at
the meeting that showed an easy simplification, which should be in the
meeting materials).
 - the delegation scheme itself

I don't think that you can underestimate the costs involved with
creating an external dependency of any sort - for any project. The
reliance on PKIX updates could be problematic.  That said, I'm not
entirely sure that this is as straightforward a win as you suggest.
If such a flag existed, using it would create the delegation problem
we were most concerned about.

I'll let others explain more of the thinking behind the delegation
problem.  I think that it's the only real issue with your proposal
that you need to worry about.  The performance characteristics are
probably manageable.