Original subtitles

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Now for directory authorities and relays within the Tor network hardcoded into every Tor client is a

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list of 10 directory or authorities or DA's these days are distributed around the world and are in charge

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of distributing an ever changing master list of all known toll relays and their capabilities.

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This list is called the consensus.

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And that's what you see here in front of you.

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This is the consensus.

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Now I know you won't be able to see this but if you go to this link this is an info graphic if you want

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to have a full breakdown of the consensus and want to know a little bit more about it.

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By Jordan right the DA's play a very important role as they are the gatekeepers that choose what relays

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are valid and when by default.

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As you know Tor bouncer's connections through three relays this circuit is chosen at random based on

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the bandwidth that is available in each country although you can manually configure the choice of relays

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if you wish.

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This is not recommended though trust is distributed and there is no central ownership because it is

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an open network.

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Anyone including your adversary can run these relays although there is a vetting process.

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But because of the onion routing they cannot see the full circuit even if they own a relay.

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If they own three relays they would be able to see the full circuit but they wouldn't necessarily know

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that it was you going in and you going out unless they performed a correlation attack.

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We will discuss that shortly.

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Each relay has a specific role.

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You can see here by the way this is a relay this is a relay.

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This is a relay on the diagram.

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The entry or guard relay is the entry point to the Tor network.

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Relays are selected to serve as guard relays.

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After being around for a while as well as having shown to be stable and having high bandwidth the middle

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relay is used to transport traffic from the guard relay to the exit relay.

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This prevents the guard and exit relay from knowing each other the exit relay is the exit point at the

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edge of the Tor network.

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These relays send traffic to the final destination intended by the client the exit relay can see the

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data sent by the client since they have to pass that data to the destination.

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This means that if sensitive data is passed on encrypted say over Haiti ETP FGP or the clear text protocols

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the exit relays can sniff the traffic they can inject into the traffic malicious code.

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As I have already mentioned this is a known vulnerability.

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It is not part of the tool designed to protect against you personally can volunteer to run a toll relay

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.

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If you have your own server or VPS a sensible question to ask might be do you get more anonymity if

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you run your own relay.

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Because lots of traffic would go through your relay so surely this would make it harder for an adversary

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to know what traffic belong to you and what traffic belongs to someone else.

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Well the answer depends on the type of attacks you're expecting which we will cover in its own section

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until we assess the various attacks.

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Let me read what the Tor Project has to say on ruining your own relay and whether this makes you more

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anonymous and attacker who owns a small number of tall relays.

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He will see a connection from you but he won't be able to know whether the connection originated at

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your computer or was relayed from somebody else.

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There are some cases where it doesn't seem to help if an attacker can watch all of your incoming and

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outgoing traffic.

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Then it's easy for him to learn which connections were relayed and which started you in this case.

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He still doesn't know your destination unless he is watching them too.

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But you are no better off than if you were an ordinary client.

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There are also some downsides to running a toll relay.

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First while we only have a few hundred relays the fact that you're running one might signal to your

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adversary that you place a high value on your anonymity.

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Second there are some more exotic attacks that are not well understood or well tested that involve making

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use of the knowledge that you are actually running a relay.

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For example an attacker may be able to observe whether you are sending traffic even if he can't actually

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watch your network by relaying traffic through your toll relay and noticing changes in traffic.

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Timing it is an open research question where the benefits outweigh the risks of running your own relay

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.

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A lot of that depends on the attacks you are most worried about the most users.

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The Tor Project thinks it is a smart move to run a relay.

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Personally I'm not really sure either but what I do know is it's always good to be on interesting and

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running a relay is definitely interesting to an adversary and I would never recommend doing it from

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your home either.

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A tip you are less likely to get complaints from your provider if you run a guard or middle relay as

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all they would see would be encrypted traffic running an exit node is a risky business as you have no

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control over what traffic goes through it and out of it on encrypted onto where you may get served with

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a copyright violation notice sued or even get a knock at the door and arrested.

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It does happen if you are thinking about setting one up.

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Check out this for configuring a toll relay on Debian and or a boon too if you are going to room one

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.

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The best thing to do is be very open about it so you can justify the traffic as not being your own.

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And the Tor Project helps a lot with this.

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So if you are going to run one.

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Check this out.

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Understand the legal side of being a relay operator.

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The Tor Project should provide guidance on any legal issues but it is of course your own risk.

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But it is good if you can support the Tor Project.