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Re: [TLS] Authentication Only Ciphersuites RFC

David Wong <davidwong.crypto@gmail.com> Tue, 26 February 2019 22:53 UTC

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From: David Wong <davidwong.crypto@gmail.com>
Date: Tue, 26 Feb 2019 23:53:39 +0100
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To: Hanno Böck <hanno@hboeck.de>
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Subject: Re: [TLS] Authentication Only Ciphersuites RFC
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Shameless plug, but have you looked at constructions like Disco
(https://eprint.iacr.org/2019/180) that target specifically this
issue?

David


On Tue, Feb 26, 2019 at 10:04 PM Hanno Böck <hanno@hboeck.de> wrote:
>
> I think I have raised my concerns before, but I have serious doubts
> there's real need for such ciphersuites.
>
> The reasoning seems to be that performance constrained devices are
> unable to do "normal" TLS. I don't have benchmarks, but it's my
> experience that people vastly overestimate the costs of symmetric
> encryption operations (by far the largest computational cost of TLS is
> the asymmetric handshake). I wonder if the people who believe they need
> an authentication only ciphersuite ever ran tests.
>
> I also see a non-neglegible risk in standardizing such ciphersuites.
> Some implementations will end up adding them and coupled with
> implementation flaws we may end up in a situation where inadvertently
> insecure ciphersuites are chosen.
>
> --
> Hanno Böck
> https://hboeck.de/
>
> mail/jabber: hanno@hboeck.de
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