[tor-bugs] #26294 [Core Tor/Tor]: attacker can force intro point rotation by ddos

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#26294: attacker can force intro point rotation by ddos
-------------------------------------------------+-------------------------
 Reporter:  arma                                 |          Owner:  asn
     Type:  defect                               |         Status:
                                                 |  assigned
 Priority:  Medium                               |      Milestone:  Tor:
                                                 |  unspecified
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tor-hs, tor-dos, network-team-       |  Actual Points:
  roadmap-2019-Q1Q2                              |
Parent ID:  #29999                               |         Points:  7
 Reviewer:                                       |        Sponsor:
                                                 |  Sponsor27-must
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Comment (by cypherpunks):

 My concern about a proof of work approach is it appears to open a back
 channel where a hidden service operator has influence over client
 behaviour. This could result in clients executing possibly rarely
 used/exploitable codepaths, or new correlation attacks. For example, the
 hidden service operator sets a requirement for a PoW that takes 1.21 KW to
 compute. The operator has also hacked in to an energy company with high
 resolution "smart" meters, then could sit back and watch as users login to
 the service.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/26294#comment:12>
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