[tor-bugs] #15186 [Tor]: Can we do HSDesc fetches using PIR, so HSDir can't learn popularity?

[Tor Bug Tracker & Wiki]

#15186: Can we do HSDesc fetches using PIR, so HSDir can't learn popularity?
---------------------------------------+------------------------------
 Reporter:  cypherpunks                |          Owner:
     Type:  enhancement                |         Status:  assigned
 Priority:  Medium                     |      Milestone:  Tor: 0.2.???
Component:  Tor                        |        Version:
 Severity:  Normal                     |     Resolution:
 Keywords:  027-triaged-1-out, tor-hs  |  Actual Points:
Parent ID:                             |         Points:
  Sponsor:                             |
---------------------------------------+------------------------------

Comment (by teor):

 In Proposal 224, the HSDir can only decrypt the descriptor if it already
 knows the hidden service's address. So that's a partial solution to this
 ticket, which makes the cost of this attack higher. (The HSDir has to try
 to decrypt each descriptor with each known address.)

 We could do better by having clients ask for N > 1 descriptors, or all
 descriptors, but that is likely to have too high a bandwidth cost.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/15186#comment:13>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online