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Re: [MLS] Deniability as external to the MLS protocol

Raphael Robert <raphael@wire.com> Fri, 13 November 2020 15:26 UTC

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From: Raphael Robert <raphael@wire.com>
In-Reply-To: <a71d2649-52f4-430f-d3c6-4ca0b10678a2@riseup.net>
Date: Fri, 13 Nov 2020 16:26:05 +0100
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To: Sofía Celi <cherenkov@riseup.net>
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Subject: Re: [MLS] Deniability as external to the MLS protocol
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Thanks Sofia!

I think this is exactly what we need to achieve optional deniability for message authorship without touching the authentication guarantees of the the core protocol.

Raphael

> On 13 Nov 2020, at 16:01, Sofía Celi <cherenkov@riseup.net> wrote:
> 
> Dear all,
> 
> As you know, we had many discussions on deniability and solving this
> problem is not an easy task, as evidence of this thread. To make sure we
> can work on this optional feature in the future, without modifying the
> core protocol, we believe that there are no changes needed to be added
> to the core protocol. Some minor relaxing of the phrasing in the
> document might be useful, though, and might help for future features as
> well, so I have submitted PR #437
> (https://github.com/mlswg/mls-protocol/pull/437). This rephrasing should
> allow deniability of application messages by allowing the usage of
> deniable signature keys. Please, let us know of any comments regarding it.
> 
> Thank you,
> 
> 
> -- 
> Sofía Celi
> @claucece
> http://claucece.github.io/
> Cryptographic research and implementation at many places, but mainly at
> Cloudflare
> FAB9 3EDC 7CDD 1198 DCFD  4558 91BB 6B45 6F44 2D02
> 
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