[tor-bugs] #10968 [Tor]: Authorities should use past consensuses to assign relay flags

[Tor Bug Tracker & Wiki]

#10968: Authorities should use past consensuses to assign relay flags
------------------------+--------------------------
     Reporter:  asn     |      Owner:
         Type:  task    |     Status:  new
     Priority:  normal  |  Milestone:  Tor: 0.2.???
    Component:  Tor     |    Version:
   Resolution:          |   Keywords:  tor-auth
Actual Points:          |  Parent ID:
       Points:          |
------------------------+--------------------------

Comment (by asn):

 Replying to [comment:6 karsten]:
 > Replying to [comment:5 arma]:
 > > Which flags did you have in mind here?
 > >
 > > For the Guard flag (#11328), I think we definitely want consensus
 values, not votes. The question is actually "what fraction of the past
 interval was this relay choosable?" If one authority thought it was
 choosable but the others didn't, then it wasn't.
 >
 > I'm still having problems understanding how the result of the consensus
 process can feed back as input into the same process.  The idea behind the
 consensus process was that the majority of authorities sure must be right.
 Like democracy.  But when you suggest that citizens should base their vote
 on past election results, that doesn't sound very democratic to me.  In
 fact, what's the purpose of voting on this flag when everyone bases their
 vote on the very same data?

 Hm. I think I see what you are saying but I don't entirely understand the
 concern. Could you describe an attack?

 At least for the guard case, as detailed in the new single guard node
 proposal (
 https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/236-single-
 guard-node.txt#l101 ) we care about how long clients have been considering
 this relay to be a guard. The only place to get this information is the
 consesus, since this is what clients use.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/10968#comment:7>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online