To: mls@ietf.org
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From: Leif Johansson <leifj@mnt.se>
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Date: Tue, 26 Mar 2019 09:39:16 +0100
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Archived-At: <https://mailarchive.ietf.org/arch/msg/mls/rQEY8nLzbtzIAlPvRaFDx4WQACA>
Subject: Re: [MLS] Federation and MLS
Precedence: list


>     3) Metadata:
> 
>     In general, some sort of metadata will need to be shared, i.e.
>     icons,  human readable user-names, group names. I would suggest that
>     as this may be an application message that is simply be considered a
>     non-cryptographic update. Any attempt to proscibe too much on this
>     layer leads to endless bike-shedding and so should be avoided :)
>     However, some minimal optional subset of metadata commonly used for
>     chat could be useful, but rather than whiteboard it, it would be
>     better to have each major MLS vendor that plans to support
>     federation see what their common subset is with everyone else, and
>     then just make a call that delivers just that as an MLS update. 
> 
> I think this will be up to the application  layer, MLS shouldn't care
> about this.
Won't this lead to spoofing-oportunities? Users will place trust in
the the artifacts that are presented to them (names, icons etc) which
means that in general such artifacts should be as tightly bound to keys
as any properties tied to the user that are designed to be used by the
protocol.

	Cheers Leif