Re: [TLS] Curve25519 in TLS

Nico Williams <nico@cryptonector.com> Thu, 12 September 2013 21:12 UTC

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Date: Thu, 12 Sep 2013 16:12:41 -0500
Message-ID: <CAK3OfOjUor1-_wv3g9_f0YO4Qtufsz1C7z18KRhpFckcdbjXgw@mail.gmail.com>
From: Nico Williams <nico@cryptonector.com>
To: Rob Stradling <rob.stradling@comodo.com>
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Cc: Simon Josefsson <simon@josefsson.org>, Patrick Pelletier <code@funwithsoftware.org>, "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] Curve25519 in TLS
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On Thu, Sep 12, 2013 at 3:57 PM, Rob Stradling <rob.stradling@comodo.com> wrote:
> On 12/09/13 21:41, Simon Josefsson wrote:
>>> So why bother making curve25519 available for key exchange?
>>
>> For performance reasons?  It is more efficient.
>
> So then...
>
> ...it sounds like it does make sense, for performance reasons, to allow
> Curve25519 (or Ed25519, presumably) to be used for keys in certs too.

Yes.

Of course, in practice it's much easier to deploy new ECDH curves for
key agreement than new signature algorithms because the former are
easily negotiated in actual protocols, while the latter are less so.
But, yes.

Nico
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