Re: [MLS] Use Cases for avoiding Forward Secrecy

Dave Cridland <dave@cridland.net> Fri, 02 March 2018 21:18 UTC

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From: Dave Cridland <dave@cridland.net>
Date: Fri, 2 Mar 2018 21:18:28 +0000
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To: Stephen Farrell <stephen.farrell@cs.tcd.ie>
Cc: Nadim Kobeissi <nadim@symbolic.software>, mls@ietf.org
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Subject: Re: [MLS] Use Cases for avoiding Forward Secrecy
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On 2 March 2018 at 21:04, Stephen Farrell <stephen.farrell@cs.tcd.ie> wrote:
>
> 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.

I'm using that term quite deliberately, I'm afraid.

"Consumers" are not the same as "People" - People act in roles, and
one such role is as a consumer. Happy to use whatever terms you like,
but not conflicting ones. "People", in general, might find a legally
recognisable record of their communications quite useful at times.

> 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.)
>

Right, totally agree.

I think it's relatively simple to ensure that a person cannot have a
"mothership", as you put it, imposed upon them without their
knowledge, and I think that's an entirely sane goal. (In fact, I think
it's met by the current drafts, which is why I'm not arguing for it).

Dave.