[tor-bugs] #6538 [Tor Client]: Use bit-twiddling tricks to make choose-by-bandwith algorithm even more time-invariant

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#6538: Use bit-twiddling tricks to make choose-by-bandwith algorithm even more
time-invariant
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 Reporter:  nickm        |          Owner:                    
     Type:  enhancement  |         Status:  needs_review      
 Priority:  normal       |      Milestone:  Tor: 0.2.3.x-final
Component:  Tor Client   |        Version:                    
 Keywords:               |         Parent:                    
   Points:               |   Actualpoints:                    
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Comment(by nickm):

 Replying to [comment:8 arma]:
 > More generally, this appears to be a complex tweak to a theoretical
 issue that is theoretically mostly solved in what we already merged? It
 includes messings to our autoconf and lots of new code. Why is it
 scheduled for 0.2.3? Or said another way, is the risk/reward ratio here
 suitable for forcing it on all wheezy users at the next rc? I see the risk
 as being somewhat low and the reward as being very low.

 The risk is that somebody on your LAN (or a local eavesdropper, or your
 entry node), can figure out about what your path is.  Conservative wisdom
 is that a fairly local attacker can detect 10-100ns timing leaks, and a
 remote one can detect 1-10ms timing leaks.  I'm especially worried about
 slow mobile devices here.

 Instead of calling the risk "low", do you mean "unproven" or something?

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/6538#comment:9>
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