9

Is the client able to detect a malicious bevaviour from an exit node? Not really. If a malicious exit relay operator conducts a man-in-the-middle (MitM) attack by using a self-signed certificate, TorBrowser will display a certificate error page. That's what everybody already knows from an ordinary Firefox. Right now, there is no easy way to distinguish ...


6

I pay for it, I run a relay. You too could help cover the cost of providing the service to users if you have the resources to spare, some time to work through some documentation and the inclination. From the "What is Tor?" answer on the Tor Project FAQ: Tor is a program you can run on your computer that helps keep you safe on the Internet. It protects ...


6

Every relay is important for the diversity of the network. The anonymity is the direct result of diversity of the network. Diversity of number of relays, diversity of number users, diversity of nature of network usage, diversity of number of directory authorities, etc. Without the diversity you may as well forget about anonymity. One can make a mathematical ...


5

Can I find out how many relays the network has and possibly where they are located? The amount of relays and bridges over time is measured. It's also possible to see the country-specific amount. Can I learn about roles the relays play in the network? For example, how many exits/guards/middle (or combination) are there? The amount of assigned flags (e.g.,...


5

I don't think the Tor client itself can detect malicious behaviour carried out by an exit node nor should it. If you're browsing a site over http:// then as you say, the exit node can view and manipulate your traffic like any MiTM could. The solution is TLS but as you pointed out there are MiTM attacks that can be launched against sites using TLS such as ...


4

Right now, Tor depends on the fact that all clients and all servers can contact all servers. Once you add relays that are not reachable from the Internet because they are behind NAT for instance, this will no longer be true. This would making arguing about Tor's security properties way harder. Somebody would have to come up with a design and its ...


4

The type of attack you are describing is a congestion attack. In theory, the simplest form of such an attack would be a general DoS on the Tor network. Taking things one step further, a congestion attack could be used in conjunction with traffic correlation to monitor a given user of the Tor network. Such a strategy is discussed in A Practical Congestion ...


4

No, a very slow (whatever that means) relay would not help. No traffic is directed to a relay below a certain bandwidth threshold. Any adversary can disregard all nodes below that threshold when considering which nodes to watch. Besides, do you really want your traffic to be routed through someones 64KB/sec soda-straw? Yeah, no one else does either. ...


3

Yes, someone already tried to do the calculation: To sum up, that would make the entire Tor network run for approximately $90,000 a month or $1,072,860 a year. Roughly the price for a (very) small tier 3 datacenter! Considering there are 1.6 million users using Tor, that would make the average user cost under a dollar per year — which is pretty cheap ...


3

Actually, the people who host the nodes. It's quite common to have an unmetered/unlimited Internet plans, so running a node costs no more than a regular Internet usage. Sometimes people do run it on VPS or physical servers - but if chosen correctly, the cost is near-zero.


3

See also this report: Jacob Appelbaum. Tor and NAT devices: increasing bridge & relay reachability or, enabling the use of NAT-PMP and UPnP by default (Technical Report 2012-08-001, The Tor Project, August 2012.)


3

It takes about 1 day for an IP address to be removed from the most recent exit list, but that directory contains exit lists published in the past 3 days. So, that's 4 days for an IP address to disappear from that directory after stopping the relay. However, there's also https://collector.torproject.org/archive/exit-lists/ which archives exit addresses ...


2

I'm not sure if I understand your question correctly, but if you can't have any incoming connection then you can't run a relay. A non-exit relay has to be able to send/receive data within Tor network. And that ExitPolicy reject *:* which is the correct setting for a non-exit relay means it will accept any connection in and out. If you're running a non-exit ...


2

Not that there's a technical bandwidth limit but it's probably not gonna be helpful for the network if you run a relay with less than 100KB/s bandwidth. For that it simply slows the network down. You can add as many relay as you want, as long as you configure the MyFamily correctly. If you have less than 100KB/s bandwidth, you may consider running a bridge ...


2

The relay would be considered 'new' each time. It would never gain the 'stable' flag or gain much consensus weight. This would neither hurt nor help the network.


1

Is there a way to enfource a new route towards my hidden services so I can circumvent the peers that are failing? From the Tor Project website, we see: An onion service needs to advertise its existence in the Tor network before clients will be able to contact it. Therefore, the service randomly picks some relays, builds circuits to them, and asks ...


1

Using your phone as a relay will take up some of your phones computing power but what I'd be worried about is mainly the bandwitdth, if you lose connection to wifi you will use up data quickly. Along with using WiFi you will stand out if you are on a public WiFi and probably not a good idea I'm home wifi. All in all it isn't worth it


1

I think it is important to continue to spread the word. I can see my peers opening up to Tor after they understand it is not 'just for criminals' but serves a greater purpose for everyone. My way of helping is to run my own relay, even though my bandwidth is not very high, and to use it as my own entry point. I believe this helps my browsing be more secure.


1

Here's my 2nd answer: If someone else is trying DoSing you over the Tor network there is a chance that this will be prevented from the guard relay. If not it could be an advantage for other relay operators because the traffic that flows through the network goes up to their score. If this someone is DoSing you over the normal internet I see no chance for ...


1

Actually, I think that might not be the case... If we were to grow the network to have more fast relays than users, that would most likely harm the anonymity. There would be high probability that each relay would only forward traffic of one or two users at any given time, which would make it easier for an adversary to "spy" on the route that a certain user ...


1

The network page of the Tor metrics portal lists approximately 5300 relays. This number should also be known to your Tor client as every client needs a full network view. So you don't need to change your configuration. The information about all relays is in cached-microdesc-consensus. The entries look like: r einfo AOsaxadU+MSjQjiVx4CM7JzZ3TQ 2014-03-03 23:...


1

There is procedure in Tor for reporting bad relays: https://trac.torproject.org/projects/tor/wiki/doc/ReportingBadRelays Send email to address bad-relays@lists.torproject.org and describe the behavior you observed (the suspicious criteria are in the wiki). There is no automatic way of detecting such nodes, only manually.


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