[tor-dev] Silly (or not so silly) question

[Noel David Torres Taño]

El mié, 23-07-2014 a las 18:34 -0400, Roger Dingledine escribió:
> On Wed, Jul 23, 2014 at 11:24:47PM +0100, Noel David Torres Taño wrote:
> > What would happen if a Tor node changes behaviour and uses four or five
> > relay steps instead of three?
> >
> > Would it enhance Tor's security?
> 
> I assume you mean a Tor client?
> 
> https://www.torproject.org/docs/faq#ChoosePathLength

I read that and it gave me the idea. I'm asking what would happen to the
network if somebody recompiles Tor to use e.g. 4 relay steps, and if it
is really noticeable to somebody. As far as I understand it, the first
hop does not know anything but that it must hand off a certain payload
to a next relay, and that relay's address, but it does not know if the
payload has two or three more onion layers.
> 
> > Is it possible to relay Tor through a Tor connection? I mean using Tor
> > with its three steps to reach a Tor entry node to get three extra steps.
> 
> Yes, it is possible. But it is currently considered a flaw, because it
> can be used to work around the 'infinite path length' defenses.
> http://freehaven.net/anonbib/#congestion-longpaths
> https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/110-avoid-infinite-circuits.txt
> https://trac.torproject.org/projects/tor/ticket/2667
> 
> > Would that difficult correlation attacks?
> 
> Defending against correlation attacks is an open research, so "maybe".
> But it's not clear how it would, since an adversary who can see or
> measure your first hop (on the first circuit) and also your last hop
> (on the last circuit) would still be in the right place to do the attack.

I thought on that, but thought also that it may be more difficult to
know which sites to monitor.

> 
> --Roger

Thanks

Noel
er Envite

P.S. It seems it was silly, after all
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