Running Tor over Tor

Question

So I am going to set up a Raspberry Pi Onion Router and I normally use the browser bundle would it be bad? More effective? Or just as effective as using just the browser bundle?

Answer 1

Tor over Tor is always worse, rule of thumb: mo' hops, mo' problems. Instead of using your RPi as a "Force Everything Through Tor" transproxy box, you should use it as an isolating proxy.

Your laptop/desktop connects to the Pi over Ethernet (this is important!). Then, your Pi connects to some wifi network with internet access and runs an instance of Tor. Your Pi provides its SOCKSPort and a ControlPort over the ethernet interface. You configure your Tor Browser to use an external Tor daemon instead of running its own by following this guide.

The reason it is critically important that you connect over Ethernet is that your Pi will receive your plain-text Tor traffic, for example if you connect to an http onion site you will send your requests to that onion in plain-text. If you did this over Wifi a reasonably competent, local adversary could decrypt the traffic and see exactly what you were doing on Tor because the connection between your laptop and the Pi is before any of Tors protection is applied. If you have to set it up using Wifi you should instead consider using OpenVPN or SSH to tunnel connections over Wifi to the Pi to stop local eavesdroppers. (yes, even WPA2 is trash by modern standards)

Please note that a Tor-over-Tor connection will always, without exception, be less safe than a normal Tor connection. There is always a possibility that your Tor connection would use the initial Tor connections guard as an exit, introduction point, rendezvous point, or in some other way interact with your own guard in such a way that it would be using a single relay for ingress and egress.

Never, ever use Tor-over-Tor. It is always less safe.

Answer 2

It is indifferent. There is the small chance (depending on the consensus weight associated to your relay, based on my experience this could happen roughy 0.01% of the times) that your TBB will use your relay as an intermediate relay (assuming that you don't allow exits), so the answer is that it is no big deal.