[tor-bugs] #8782 [Tor]: Don't give up so easily on your guards if the consensus calls them Running

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#8782: Don't give up so easily on your guards if the consensus calls them Running
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 Reporter:  arma         |          Owner:                    
     Type:  enhancement  |         Status:  new               
 Priority:  normal       |      Milestone:  Tor: 0.2.5.x-final
Component:  Tor          |        Version:                    
 Keywords:  tor-client   |         Parent:                    
   Points:               |   Actualpoints:                    
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 If your guard ever fails to do everything you demand, you'll mark it as
 not running for several hours (i.e. until you get a new consensus that
 tells you to forgive it). So an attack to railroad you onto the
 adversary's guard (even if temporarily, which isn't so bad for a normal
 client but is super scary for a hidden service) gets cheaper.

 It would be wise to forgive guards in the "we decided they're down but our
 consensus still says they're up" state much more quickly and often. That
 changes the attack from a serial "get us to mark each guard down one at a
 time" to either requiring you to do it in a much shorter time frame, or
 the more expensive parallel "keep a growing set of guards all down until
 the victim chooses ours".

 (A discussion with rpw at 29c3 reminded me of this issue, and now ongoing
 discussions with Rob re-remind me of it.)

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/8782>
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