[tor-bugs] #18749 [Tor]: Consider only including one fallback per operator

[Tor Bug Tracker & Wiki]

#18749: Consider only including one fallback per operator
---------------------------------------------+-----------------------------
 Reporter:  teor                             |          Owner:
     Type:  enhancement                      |         Status:  new
 Priority:  Medium                           |      Milestone:  Tor:
Component:  Tor                              |  0.2.???
 Severity:  Normal                           |        Version:
 Keywords:  029-proposed, TorCoreTeam201609  |     Resolution:
Parent ID:                                   |  Actual Points:
 Reviewer:                                   |         Points:  small
                                             |        Sponsor:
---------------------------------------------+-----------------------------

Comment (by teor):

 (I wrote a long reply to this and then lost it when my laptop crashed.)

 My plan is:

 Mitigate known, significant uptime / privacy risks when generating the
 list:
 * same operator
  * contact (can be gamed)
  * effective_family (other family fields can be gamed)
 * same IP
  * IPv4
  * IPv6 (unlikely)
 * some operators have told me that different IPs are on the same box, and
 I only whitelisted one of their relays

 Analyse other risks after generating the list:
 * netblock
  * IPv4
  * IPv6 (I'm unsure what a reasonable netblock is for IPv6)
 * ports
  * IPv4 dirport
  * IPv4 orport?
  * IPv6 orport??
 * IPv4-only / IPv4 & IPv6
 * non-Exit / Exit

 Leave some analysis to others after the list is created in the release
 candidate:
 * AS
 * Country
   * country is often inaccurate for servers, which are often given the
 country of the ownder of the netblock, regardless of actual location

 I'm hesitant to modify the list too heavily, because each time we add a
 rule that excludes relays:
 * we lose bandwidth,
 * we make the system easier to game,
 * we may make some privacy or uptime factors worse, particularly if we
 don't analyse them straight away, but they later turn out to be important.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/18749#comment:7>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online