Re: [TLS] WGLC for draft-ietf-tls-tls13-cert-with-extern-psk

Russ Housley <housley@vigilsec.com> Fri, 31 May 2019 22:11 UTC

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From: Russ Housley <housley@vigilsec.com>
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Date: Fri, 31 May 2019 18:11:08 -0400
Cc: Hugo Krawczyk <hugo@ee.technion.ac.il>, IETF TLS <tls@ietf.org>
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Subject: Re: [TLS] WGLC for draft-ietf-tls-tls13-cert-with-extern-psk
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> On May 31, 2019, at 5:31 PM, Geoff Keating <geoffk@geoffk.org>; wrote:
> 
> 
> 
>> On 21 May 2019, at 2:08 pm, Hugo Krawczyk <hugo@ee.technion.ac.il>; wrote:
>> 
>> A clarification on the text suggest below by Russ.
>> 
>> The way I see it, the external PSK as used in draft-ietf-tls-tls13-cert-with-extern-psk is not intended as a means of authentication but as a way of regaining forward secrecy in case the (EC)DHE mechanism is ever broken (e.g., by cryptanalysis or by a quantum computer).
> 
> It’s a bit problematic if the expected use of the draft is with quantum-resistant certificates, because TLS doesn’t support those yet.

That is not the way I read Hugo's note, and that is certainly not called for by this draft.  Quite the opposite.

Russ