Re: [TLS] Data volume limits

Hanno Böck <> Tue, 15 December 2015 22:36 UTC

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Date: Tue, 15 Dec 2015 23:36:39 +0100
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Subject: Re: [TLS] Data volume limits
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On Tue, 15 Dec 2015 13:14:30 -0800
Eric Rescorla <> wrote:

> Watson kindly prepared some text that described the limits on what's
> safe for AES-GCM and restricting all algorithms with TLS 1.3 to that
> lower limit (2^{36} bytes), even though ChaCha doesn't have the same
> restriction.
> I wanted to get people's opinions on whether that's actually what we
> want or whether we should (as is my instinct) allow people to use
> ChaCha for longer periods.

Let me state the opinion that unlikely will get adopted: Isn't that a
good reason to reconsider whether GCM is a good mode in the first place?

How about: Let's use chacha20, let's not set any limits because we don't
have to, let's deprecate algorithms that can't keep up with that?

(I generally think even TLS 1.3 deprecates a lot of stuff there is
still far too much variation. Let's keep things simpler, let's reduce
the algorithm zoo.)

Hanno Böck