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Re: [Cfrg] matching AES security

Nico Williams <nico@cryptonector.com> Wed, 30 July 2014 22:38 UTC

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Date: Wed, 30 Jul 2014 17:37:54 -0500
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From: Nico Williams <nico@cryptonector.com>
To: Robert Moskowitz <rgm-sec@htt-consult.com>
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Subject: Re: [Cfrg] matching AES security
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On Wed, Jul 30, 2014 at 9:06 AM, Robert Moskowitz
<rgm-sec@htt-consult.com> wrote:
> On 07/30/2014 08:33 AM, D. J. Bernstein wrote:
>
> Dan,
>
> Please explain what typical device will use at least one new key every
> minute?

Er, well, smartphone apps might well poll/get pushed to that
frequently, altogether, with a new key per-poll/push.  Sure, the
protocol involved might not generate a new key per-event, but if the
protocol is TLS, then it will.

DJB's point is that we should permit "odd" match-ups like AES-256 and
Curve25519 _because_ AES-128 is weak in plausible scenarios.

I'm having a hard time objecting to that!

(BTW, that's a much more serious problem for Kerberos than for TLS w/
session resumption.)

Nico
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