[tor-talk] A possible solution to traffic correlation attacks,

[notfriendly at riseup.net]

On 2016-06-05 18:43, Paul Syverson wrote:
> On Sun, Jun 05, 2016 at 05:20:24PM -0400, Allen wrote:
>> >
>> > So randomizing the times that traffic enters the network and exits the
>> > network wouldn't work? Like it enters a note and 30 ms after received or
>> > another random delay couldn't it exit. It would be harder to correlate the
>> > traffic right?
>> 
>> 
>> IMO, the packets would probably need to be randomly delayed at each 
>> node,
>> not just entering and exiting the network.  A mathematical model would 
>> be
>> needed to determine the necessary amount of delay (I doubt 30 ms would 
>> be
>> enough).  The delay could be chosen by the originating node, so it 
>> could
>> chose the privacy vs latency tradeoff.
> 
> You guys might want to look at the stop-and-go mix paper (Kesdogan et 
> al. 1998)
> and the alpha mixing paper (Dingledine et al. 2006) at 
> freehaven.net/anonbib/
> Other topics touched on in this thread include defensive dropping
> "Timing Attacks in Low-Latency Mix-Based Systems" Levine et al. 2004,
> also at anonbib.
> There are many research papers that have explored aspects of these 
> ideas.
> 
>> 
>> It might also be beneficial to have two channels to each exit node, 
>> with
>> each channel used in only one direction, i.e., outbound packets travel 
>> one
>> route, while inbound packets travel a different route.
> 
> For this you might look at
> "Preventing Active Timing Attacks in Low-Latency Anonymous 
> Communication"
> Johnson et al. 2010, also on anonbib
> 
> aloha,
> Paul

I just downloaded the PDF and will read it later tonight.