(Moving this thread from tor-relay)

El 03/10/17 a las 14:25, teor escribió:

On 3 Oct 2017, at 10:57, Roman Mamedov <rm@romanrm.net> wrote:

On Tue, 3 Oct 2017 09:53:46 -0400

teor <teor2345@gmail.com> wrote:

  For interposing dual-protocoled nodes along the way, how many do there

have to be for it to become "not too limiting"?

This is one of the questions we need researchers to answer.

I can't help but feel you are overcomplicating this.

Clients create a circuit by randomly picking 3 nodes out of the all-nodes

pile, right? If all 3 happen to be IPv6-capable, then the circuit can go over

IPv6 and all is fine. If some of the 3 happen to be IPv6-only while others are

IPv4-only, the whole selection can be thrown away and repeated.

That way IPv6-only relays could get some usage on a totally random basis, with

no compromises and no restraining "of the next hop based on the previous one",

not hurting anonymity. Clients just need to know which nodes are IPv4-only,

IPv6-only or dual-stack, to not attempt unworkable combinations, discarding

them instead.

Discarding unworkable combinations and restraining node choices seem

equivalent to me, although the relay weights may be different.

And as there are more and more dual-stack or IPv6-only relays, the "throw

away" step will be needed less and less often.

If you think this will work and is safe for client anonymity, then the next step

is to write a tor proposal. Having a concrete design could help with

analysing the anonymity implications as well.

I think IPv6-only relays are a lower priority than better IPv6 and dual-stack

client support, and IPv6-only bridge support  But we could do both in the

same release.

Hello tor-dev,

With my colleague JC Bach (in CC), we have proposed a last-year student
project to address IPv6-related issues in Tor for the upcoming semester,
at IMT Atlantique engineering school. There will be two students working
on it. It is hard to say now how far we will arrive, especially because
this is our first approach to Tor entrails.

So this message is to say we have good chances to come back here looking
for help :-)