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Re: [TLS] Authentication Only Ciphersuites RFC

Hanno Böck <hanno@hboeck.de> Tue, 26 February 2019 21:03 UTC

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Date: Tue, 26 Feb 2019 22:03:35 +0100
From: Hanno Böck <hanno@hboeck.de>
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Subject: Re: [TLS] Authentication Only Ciphersuites RFC
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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/

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