15

Although Tor is made to handle any TCP traffic, the majority of applications are not designed with anonymity and/or privacy in mind. Thus, torifying an application can be tricky. You have to make sure that there is no leak i.e connections routed outside the Tor circuit. A pretty usual example is DNS leaks. If you want to use other applications apart from a ...


13

Third-party audits are most valuable for closed-source software where there is a restriction on who can look at the source code. In contrast, Tor is open-source so anyone can look at the source code and check for back-doors. Lots of people have looked at the Tor source code, as can be seen from the number of researchers which have modified Tor and the ...


13

No. Or at least, there aren't supposed to be any ways for the interaction to hurt your anonymity. If you find any, please let us know! That said (and because there are always exceptions), check out the paper "Website Detection Using Remote Traffic Analysis" from PETS 2012. If your non-Tor traffic is interacting with the adversary (which might be more ...


12

Running a guard node (aka an entry node) is safe for the person running it. The reason there aren't as many of them is because there are certain criteria that must be met before your relay can be used as a guard node: The relay needs to have first appeared longer ago than 12.5% of the relays, or 8 days ago, whichever is shorter. The relay needs to advertise ...


12

"...Windows is full of key-loggers, Trojans and..." is a bit overblown. In general, the chances of a Windows box being infected with malware are higher than a Linux box. Mainly because Windows is a very popular target. Since Windows is closed source, as opposed to Linux which is open source, you (the user/consumer) can not tell what key-logging, screen-...


11

Your question is quite hard to answer, because as far as I know the special capabilities of the agencies in this field are yet unknown. However you can first look into Tor's design document. Section 3.1 states: A global passive adversary is the most commonly assumed threat when analyzing theoretical anonymity designs. But like all practical low-latency ...


10

Yes, that is a distinct possibility. To prevent this the Tor project recommends a range of actions to make it clear you're running an exit relay; for instance informing your ISP. You can read a blog post regarding this here.


9

To add to the other reasons of why this is a bad idea, there are also legal issues with monitoring or modifying traffic going through your exit node. From the Tor legal FAQ: Should I snoop on the plaintext traffic that exits through my Tor relay? No. You may be technically capable of modifying the Tor source code or installing additional software to ...


9

Tor can handle all TCP-based connections. This is browsing, email, chats and others. The wiki has a howto for torifying applications. This explains how you set up software so that it works with Tor. In general you should not use BitTorrent with Tor. Because on the one side it puts a high load on the Tor relays and the network will slow down for all users. ...


9

It's prudent to use open-source software, given the greater risk of backdoors in closed-source products. You want to thoroughly lock down remote access to the server. In my experience, servers are constantly hammered by login attempts. It's crucial to disable password-based ssh logins, allowing only key-based logins. I've also seen thttpd recommended for ...


9

Using the HTML Canvas a malicious website can perform various tests to learn a large array of information, in relation to graphics, which can be used to fingerprint users. Tor Project design docs (under 4.6, section 2. HTML5 Canvas Image Extraction) After plugins and plugin-provided information, we believe that the HTML5 Canvas is the single largest ...


9

There's one important fact that makes such an attack extremely difficult. A connection between a Tor client and a Tor hidden service is actually composed of two entirely separate circuits that both connect to a rendezvous point. One circuit is set up by the client, the other by the server. Therefore, the client doesn't know which relays the data uses on ...


9

Normally the Tor service should be started/stopped with either sudo systemctl start/stop tor.service or sudo service tor start/stop. Personally I've always used the service command because it is simpler. I'm guessing things get a little more complicated when you run multiple Tor instances, but I have no experience with that. Running Tor in a terminal runs ...


8

This isn't Firefox option per se, but consider clicking Use new identity after every task you do using Tor. This will ensure it looks like you are connecting to Tor for first time, and no one will be able to match your new connections to older ones.


8

The short answer is: You shouldn't do it! Do not mess with user data. A large portion of Tor users use it to stay anonymous and they would be very upset when someone messes with their traffic. It is quite hard to decide what spam, malware etc. from the perspective of each user is. So a general filter doesn't fit all your users. If you want to let your ...


8

TAP is the original Tor Authentication Protocol, the one described in the original Tor paper (html). A security proof was later done by Goldberg at PET2006 and I think this is where the name of the scheme and the TAP acronym comes from. NTor is a new protocol that aims to use faster and stronger cryptographic primitives. It is specified in proposal 216 ...


7

From what I can see Tor mainly handles your web browser's traffic, but is there a way to do all of your connections through it? Like email, Dropbox, Carbonite backup, Skype etc? Transparent Proxies such as Whonix and QubesOS TorVM can route all traffic through Tor. Routing all traffic through Tor is nowadays not the only thing. You also have to consider the ...


7

In addition to Jens' answer, from the front page of Tor project website: For most uses, Tor provides the best available protection against a well-resourced observer. It's an open question how much protection Tor (or any other existing anonymous communications tool) provides against the NSA's large-scale Internet surveillance. On its own, Tor can't ...


7

All the downloads are "signed". This means that someone (in this case Erinn, a Tor Project Developer) vouches that the software is good and hasn't been tampered with. You can verify the download by also downloading the signature file, and using GPG to check that the signature is valid for the downloaded file, and that they were signed by Erinn. More ...


7

Tor does not have a concept of exit nodes that only you can use. The routing protocol allows for it, but there is no support in Tor or its directory layer for what you ask.


6

The simplest (relative term) method of breaking onion routing is a correlation attack performed by a global adversary that controls a majority of nodes in the network. What that means is that somebody watching your entry and exit node can correlate requests coming in from your computer to their entry node at time n and leaving their exit node at time n1 for ...


6

Another idea is to prevent the computer you run Tor on from knowing your external IP address by connecting it to the Internet via a NAT router. This helps mainly in combination with something like Tails which prevents Internet access except via Tor. Even if your Firefox gets compromised it won't be able to send out requests directly to the Internet (due to ...


6

You can use any application that supports the SOCKS 4 or 5 protocol directly with Tor. Or you can use a wrapper utility on those who do not. You can find some configuration tips over at the official and Arch wikis. As mentioned in the other answers already, you can use the Tails Live Distribution to ease the setup. That said, you should be aware that some ...


6

Yes, in a sense they are less secure since it's probably trivial, given sufficient access, to copy the system. Real hardware requires physical access and is, perhaps, easier to detect: an extended and/or unexplained downtime would probably be noticed. However, diversity is very important for the Tor network. Therefore, if the choice is between a bridge or ...


6

"Does Tor still present a threat to the NSA?" I believe that Tor was never threat to the NSA. There are several layers of 'protection' about Tor, thus several ways to attack users. The first layer is: software code. NSA software developers can misuse open code to find holes and bugs in the code. We can surely make the presumption that the NSA doesn't have ...


6

Email information is publicly available so you'd better use a special email address for your relay. Either set up a fresh one (optionally via Tor) or check if your email provider gives the opportunity to set up email aliases. This way you can handle better spam bots. Email contact is useful in case someone wants to reach you and in general is the kindest ...


6

As highlighted on the Tor Project's homepage, Tor's objective is: Anonymity Online. Protect your privacy. Defend yourself against network surveillance and traffic analysis. To that end there are many developers, journalists, hackers, cryptographers, activists, government agents and more constantly evaluating Tor's effectiveness from both theoretical and ...


6

I would say advantages of ECC are: Performance—see Curve25519 performance on linked page More analysis—this is debatable, but I would say ECC is better understood in the crypto community than lattices. Spotty history of NTRU, which had to be revised several times, IIRC, based on cryptanalytic attacks. I think there might also be patent issues around NTRU, ...


Only top voted, non community-wiki answers of a minimum length are eligible