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5 votes
Accepted

Tor dying on Raspberry Pi (circuit creation storm, out of memory)

Linostar's answer is on the right track, but missed the Tor version you specified. You should update to at least the 0.2.5.x series for Tor to try and detect out of memory situations and handle them ...
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4 votes
Accepted

How does Tor defend against Sybil attacks?

Lizard Squad was a pretty noisy sybil. We have monitoring for events of that sort... https://gitweb.torproject.org/doctor.git/tree/sybil_checker.py Naturally that event has sparked interest in more ...
  • 691
4 votes

On Dec 26 2014 the number of relays have increased from 6700 range to 10000 range overnight. What is going on?

This is an ongoing attack on the Tor network. A group has established ~3000 relays (and growing), ~50% of network nodes (note, network nodes, not network capacity for which I don't have a decent ...
  • 3,730
4 votes

How to tell my Tor Browser to use a certain relay as entry point?

To manually set an entry node see the following FAQ entry: Can I control which nodes (or country) are used for entry/exit? Yes. You can set preferred entry and exit nodes as well as inform Tor ...
  • 3,730
4 votes
Accepted

How to tell my Tor Browser to use a certain relay as entry point?

While I don't have an expert answer, I can draft some thoughts on your first question. To estimate one's security level you have to define what your adversaries' capabilities are (technical skills, ...
3 votes

Relay streaming a large file

Exit relays will continue reading until circuit dies (in old versions) or buffer of a relay becomes too big (in new versions, intended to prevent DoS) . If you are a 'honest' client, the exit node ...
  • 725
3 votes
Accepted

What prevents directory server from being attacked?

What prevents a directory server from being dishonest and give malicious data to the user? The information served by the directories is generated by reaching a consensus between the authorities. You ...
  • 1,342
3 votes

Does facebook's hidden service url mean that collisions are feasible?

No, and yes. Facebook, hidden services, and https certs had talked on this. Facebook in fact brute forced only the first 40 bits and then made a backronym. Their hidden service name is "...
  • 725
2 votes

Are low bandwidth DoS attacks performed over the Tor network a problem to be considered?

Is there any other serious obstacle for such attacks over Tor? Many services will automatically block exit nodes, or will be more strict with detecting possible attacks from exit nodes. Even if they ...
  • 21
2 votes

Releasing a controversial movie torrent using Tor Network for security

I know this isn't exactly what you asked for, but because Bittorrent over Tor isn't considered the best thing to to there are other options. Depending on what you mean by "movie", another option ...
  • 1,182
2 votes

Releasing a controversial movie torrent using Tor Network for security

At Tor blog they say it is not good idea to seed via Tor network. I think best bet of yours would be using Tor browser to contact anonymously someone from non-standard country to seed the torrent for ...
  • 141
2 votes
Accepted

How to prevent a rogue Tor entry node?

You know that some rogue entry node isn't faking Tor circuits because your Tor client specifies the relays used in each circuit, and because the circuit-creation process requires that each relay ...
  • 2,989
2 votes

Is exit node able to modify / add packets to a stream?

Yes, the exit relay can do any of the behaviors you describe. It can modify the data that comes back from the website (or whatever the destination is), or it can simply pretend to be the destination ...
2 votes

Whonix Workstation Country Code

Packets won't carry your local time information, application data will though. You probably want to make your timezone UTC since this is the most "generic" timezone and the easiest to calculate your ...
  • 10.8k
2 votes
Accepted

List of attacks on Tor

I don't think anyone will do your research for you but here are some links with a lot of good information. Paul Syverson's home page Roger Dingledine's home page 2012 Tor Specification Selected ...
  • 2,191
2 votes
Accepted

Can Tor connection be intercepted/tampered by exit nodes?

Yes, the exit node can inspect and tamper with the TCP traffic as it leaves the network. It's impossible for Tor to provide integrity for this traffic. You should always use secure protocols like TLS/...
  • 2,898
2 votes

Tor safe when taking future in to account?

Quantum threat is a real thing, especially in context of Shor's algorithm for a possible attack vector, for example. But there're a lot of quantum-resistant things like LWE and some EC's, so - using a ...
  • 5,471
1 vote

Tor dying on Raspberry Pi (circuit creation storm, out of memory)

It may or may not be an attack, but my personal opinion is that Tor isn't guessing the right values for some parameters like MaxMemInQueues (like it was setting them too high, then too low later). Try ...
  • 1,195
1 vote
Accepted

Does a tor message keep track of number of nodes it's gone through?

The circuit path is decided in advance, before the message is created. During circuit creation, the number of nodes through which the circuit can pass is limited to 8. This limitation prevents ...
1 vote
Accepted

Security for relay on Home network

... am I somehow increasing my attack vector ... or is it just additional attention that makes security important? A little bit of both. As with any service you host, you let the internet connect to ...
  • 3,745
1 vote

TOR traffic correlation: how quickly can you be de-anonymized?

The best case as reported by the leaked documents, where the NSA was able to bust someone from Tor, involved exploiting the Tor browser bundle with 'Quantum insert' (Man-on-the-side-attack) and ...
  • 708
1 vote

List of attacks that try to trick browser to not use SOCKS/Tor

adding to the types you've mentioned there're two other kinds of them: Zero-Day exploits Tor browser is a Firefox by roots, so some Firefox zero-day exploits are affecting it too. It's OK for any ...
  • 5,471
1 vote
Accepted

How do bridges defend themselves against targeted scans?

Yes, the issue you're describing is a real issue and has been thought about a lot before. The suggestion to use port 443 has been removed due to your question, now the suggestion is to use a random ...
  • 2,209
1 vote

Is exit node able to modify / add packets to a stream?

An exit node can not initiate a stream to a client or on behalf of a client. Only clients can initiate streams. Once a client has established a stream, if the service is plaintext, the exit node can ...
  • 3,745
1 vote

Ready-made Tor relay on virtual machine

Do you mean relays or clients with browsers? Your mention of users and screens and browsers suggests the latter. The question you link to is also about Tor Browser, not relays. A ready-made Tor ...
  • 3,745
1 vote

What would happen if directory authorities were compromised or taken down?

If there are not enough directory authorities online for a consensus, the network will die out as the consensus expires. If no directory authorities are online, new clients are unable to download an ...
  • 3,745

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