Re: [MLS] Use Cases for avoiding Forward Secrecy

Stephen Farrell <stephen.farrell@cs.tcd.ie> Fri, 02 March 2018 21:04 UTC

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To: Dave Cridland <dave@cridland.net>, Nadim Kobeissi <nadim@symbolic.software>
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From: Stephen Farrell <stephen.farrell@cs.tcd.ie>
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Subject: Re: [MLS] Use Cases for avoiding Forward Secrecy
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Hiya,

On 02/03/18 20:27, Dave Cridland wrote:
> To be absolutely clear, I'm not a big fan of SAKKE and I think it's
> entirely unsuitable for the consumer in any form. Consumers generally
> benefit from FS, and SAKKE's mandatory escrow is just plain wrong in
> that setting.

I agree with you about mikke-sakke and mandatory key escrow in general.
(As does the IETF, in RFC 1984/BCP 200.)

As a non-nit: I'd much prefer we consider people and not "consumers,"
but no need to go there as part of this thread - I know what you meant
when saying "consumer" above and it's ok in context. However, I do hope
work on MLS does not assume the existence of a major "mothership" - if
it did, then that'd be bad IMO, regardless of whether a mothership is
an employer, government or commercial service provider. (Allowing for
the existence of such entities is ok IMO, requiring them is not.)

> The properties that interest me within MIKEY-SAKKE are the possibility
> of a secure archive with offline escrow, and I think we can do that
> within MLS after discussion.
> 
> I actually think this is a fairly well-understood requirement, and as
> such it'd be useful to document it somewhere in the charter.

Fair enough. The potential that archives can be kept is reasonable,
even if the putative MLS-wg/RFCs mightn't specify an interoperable
way to do that.

Cheers,
S.