[dnssd] dnssd privacy

[Daniel Kaiser <[e-mail]>]

Dear all,

i am a PhD student working in the field of privacy with respect to
service discovery protocols.
I attended today's dnssd meeting where you asked for contributions to
draft-rafiee-dnssd-mdns-threatmodel.
If you think the part on privacy problems is worth extending, I would be
glad to contribute.

Further I wanted to ask about possible solutions for the privacy problem,
which I think is especially relevant for services that carry sensitive
data in the TXT record (e.g. _presence).
RFC 7558 Section 6.6 proposes to give users an opt-in for scope selection.
What do you think about a possibility for users to choose whom service
information is offered to, while keeping the way it is now as a default
(we wrote a paper about that [1]).
Services which use sensitive TXT records tend to be relevant for only a
small group of users anyway.
This would demand the existence of pre-shared knowledge, which could be
transmitted over
an out-of band channel (e.g. Facebook or XMPP, giving users the
possibility to privately offer information about services
to an existing list of friends).

kind regards
Daniel

[1]  http://kops.uni-konstanz.de/handle/123456789/29817