Re: [TLS] DTLS 1.3

Nikos Mavrogiannopoulos <nmav@redhat.com> Thu, 07 July 2016 08:13 UTC

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From: Nikos Mavrogiannopoulos <nmav@redhat.com>
To: Stephen Farrell <stephen.farrell@cs.tcd.ie>
Date: Thu, 07 Jul 2016 10:13:37 +0200
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Subject: Re: [TLS] DTLS 1.3
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On Tue, 2016-07-05 at 15:24 +0100, Stephen Farrell wrote:
> it doesn't contribute nor affect the security in any way).
> > > Does that id need to be static? If so, then it'd act as an
> > > additional way to track a user roaming over different IP and
> > > ports. That'd be a pity. If such an id is useful, maybe there's
> > > a way to allow it to change as well, in a way predictable for
> > > the server.
> > Could be, but I don't have a use case for such 
> Hmm. I'd hope we can all share a use case of bring more
> privacy-friendly where possible and of not introducing
> changes that are privacy-unfriendly unless absolutely
> unavoidable.

Thank you, now I understand your concern. However, I would like to
point that a static identifier does not make the situation any worse
than we have today. DTLS over UDP (or any other layer) is not
anonymous, and DTLS as a protocol it was never meant to be. Moreover,
any method to have a dynamic identifier should be of complexity that
would make such an approach reasonable for a server to calculate
without state (the problem this identifier solves is that a server
doesn't know to which client this session belongs on receipt of a
packet, thus it would have to calculate any dynamic identifiers without
any state).

regards,
Nikos