Questions tagged [circuit]

A Tor circuit is a private network pathway built incrementally as a series of encrypted connections through relays on the network.

Filter by
Sorted by
Tagged with
24
votes
3answers
9k views

How does a Tor client pick Tor nodes for circuit creation?

A Tor client initially contacts Directory Authorities to fetch the consensus (i.e. a file containing all relays of the Tor network at that time with details such as IP address, exit policy, public key ...
16
votes
3answers
9k views

For how long does a circuit stay alive?

How long does it take for Tor to expire a circuit and pick a new one? Is there a way to control this expiration time?
15
votes
2answers
1k views

Does Tor insert random delays or perform packet re-ordering to make the discovery of the communication path harder?

If an attacker can observe the Tor user, and the website being visited, it is possible to correlate the traffic by looking at time and size distributions of the communication. Techniques such as ...
13
votes
2answers
2k views

When I click “New Identity”, why do I sometimes end up with the same exit relay?

Three variants on the same question: If I click "new identity" in Tor Browser to get a new circuit, why does my new circuit sometimes have the same exit relay as the last circuit? Doesn't that hurt ...
11
votes
2answers
816 views

How many distinct Tor circuits are possible?

Given the current relay census, and assuming a standard Tor Browser Bundle installation, approximately how many distinct Tor circuits are possible? Once entry guards have been chosen, approximately ...
11
votes
3answers
5k views

How can a new circuit happen without closing all tabs?

Using the current version (3.5) of the Tor Browser Bundle, how can we switch to a new circuit without losing all tabs and activity? I understand the reason of "New Identity" means everything is ...
11
votes
1answer
538 views

Why does the number of open circuits fluctuate that much in my heartbeat logs?, new d

I have a new exit relay running on DSL. It's version 0.2.3.25 running on Windows. Most of the time, there's only a few connections, but every so often there's a lot more. They all appear and disappear ...
10
votes
1answer
518 views

Do all relays in a circuit encrypt data response from a server?

I know that when sending data from the Tor client to a server it is encrypted and gradually get decrypted on the way there. This question is about when the server responds. The data must be encrypted ...
9
votes
1answer
141 views

Does Tor take node age into consideration when building a circuit?

I've seen this for a while, but in my experience Tor seems to select well stablished nodes (whose uptime is >60 days) but in the specifications this is not shown. It's just that the current list of ...
9
votes
1answer
78 views

Can intermediary nodes learn the length of a circuit?

This should be impossible because of the layered encryption, but some documentation suggests that this can somehow be done. From Section 5.6 [1] of tor's specification When speaking v2 of the link ...
8
votes
4answers
20k views

How to change the entry node?

When Tor changes circuit it only changes middle node and exit node, the entry node stays the same since the Tor started, so I guess the entry node is limiting the traffic if you make too much traffic,...
8
votes
1answer
801 views

Suddenly my Tor hidden service isn't available

I created a Tor hidden service (a server binded to localhost port and torrc config'd to use the 127.0.0.1 xxxx) for clients to connect to. It was working great for a month or so, and now no one can ...
7
votes
1answer
2k views

How to force Tor to use just one circuit?

We use Stem's launch_tor_with_config with the following config and then close all circuits opened by it (with close_circuit). MaxCircuitDirtiness and NewCircuitPeriod: tens of hours ...
6
votes
1answer
271 views

How much does it cost to change Tor identity?

Assume we are refreshing a web page very quickly and fresh identity is needed for each request. My question is how often we can change IP on Tor network? More briefly how much computation and how ...
6
votes
2answers
156 views

How does Tor client build circuits when using a bridge?

When using a bridge, if my own Tor client builds the circuit, how does it know relays IP addresses (middle and exit IP addresses and their public keys) ? Does it take them from the bridge?
6
votes
1answer
402 views

How to interpret the Circuit handshake stats?

What do the numbers in Circuit handshake stats since last time: 1833867/1833868 TAP, 159257/159257 NTor. mean? Is it how many of them were completed?
6
votes
1answer
276 views

Is it possible to team multiple circuits in the current Tor network?

The client-selected paths that carry traffic through the Tor relay network are called circuits. Tor clients switch circuits at ten minute intervals for better anonymity. However, latency and bandwidth ...
6
votes
2answers
349 views

Can somebody force my Tor circuits to always start from his “guard node”, to access my traffic?

The first node after "my browser" is always the same. I am worried to see that even when asking for "new identity" or "new circuit", it restarts always by the same IP address in France. I have no ...
6
votes
1answer
528 views

Circuit Build Times in Tor

Why does Tor save the circuit build times and what does it want to learn out of them? Tor loads the circuit build times from a file at the beginning. I do not know why it needs them.
5
votes
3answers
403 views

Can Tor's IP sharing be dangerous?

I am novice to Tor, but before using it I have gone through lot of websites. An article explained that Tor is dangerous the following reason: Consider an IP 1.2.2.2 which was assigned by Tor to user ...
5
votes
1answer
98 views

How feasible is that Directories grant you only compromised nodes to build the circuit from?

I asked this question about Tor and how secure are the first steps before the circuit is made (the guy who answered me, lead me to this site which i didn't know). Please correct me if I'm wrong (or ...
5
votes
2answers
414 views

Does Tor use compression?

Just curious if out of the box does Tor use a Gzip or any other kind of compression? I have done some searches but find only discussions about the Hidden Service directory.
4
votes
2answers
3k views

What happens with TCP connections on SIGNAL NEWNYM?

When I send the NEWNYM command tor will build new circuits. I'm wondering what happens with open TCP connections. Will tor wait a certain timeout to give them a chance to close, or do I break those ...
4
votes
2answers
1k views

Accessing Tor hidden services over a single hop circuit

I will presage the expected warnings before posting my question: I fully understand the security risks involved using single hops, however, with regards to my goals I have zero need for anonymity. I ...
4
votes
1answer
1k views

What does Tor do with streams?

I am a bit confused about handling streams in Tor. When we visit a website like Youtube the browser sends more than 100 requests to more than 20 different hosts. If we consider each request is for a ...
4
votes
2answers
649 views

Tor circuit selection

Quick question - is it possible to 'exclude' or 'bypass' certain Tor Circuits? Example: At this moment it shows the circuit as France - Netherlands - France. What I am wondering is, can I tell Tor to ...
4
votes
1answer
236 views

What are cannibalized circuits and how Tor make use of them?

Bug report #5231 mentions cannibalized circuits: This can happen when we cannibalize a circuit which has already been cannibalized. What are cannibalized circuits and how they're used in Tor? And ...
4
votes
2answers
438 views

How many streams does Tor attach to the same circuit?

How many streams does Tor attach to the same circuit, i.e. when Tor think that it is a time to build a new circuit? I know that the lifetime of a circuit is 10 minutes (for new connections). But ...
4
votes
1answer
169 views

How many preemptively built circuits?

I want to know how many preemptively circuits Tor can builds. I got confused about it when I read "Tor Path Specification". According to this article, at the startup Tor builds 3 clean circuits, but ...
4
votes
1answer
308 views

Does traffic exit Tor at the same node for all ports?

Exit Relays can be set to allow traffic to exit the Tor network only over certain ports. Vidalia even makes this super-simple by giving options like "Normal, unencrypted Web browsing" or "IRC clients ...
4
votes
2answers
225 views

How does Tor protect against flooding with artificially long circuits

Since the path and the length of a circuit can be chosen by a modified client an attacker could make it arbitrarily long and thus multiply the the impact of his traffic on the network by the amount of ...
4
votes
1answer
224 views

Where along the path is encryption used?

This question is born out of two questions that I saw coming up. Is the connection between my computer and the Tor network encrypted? How does Tor encrypt my traffic before it sends it to the server?...
4
votes
1answer
566 views

How does TOR extend circuit to a third node?

I am reading the Tor: The Second-Generation Onion Router article and my question is that how TOR extends circuit to a third node? On page 7 of the article,left column, it says: To extend the ...
4
votes
2answers
924 views

Tor is only assigning circuits from a very limited subset of exit nodes

I am researching Tor, and as part of my research I was curious how many distinct exit relays a real-world client would include in building circuits. For my purposes, I am only interested in US exit ...
4
votes
1answer
382 views

Finding the IP address of a hostname on a given circuit

I want the Tor to just find the address of a hostname (just give me the IP) on a given circuit without be connected to that hostname. I find that the RELAY_CONNECTED cell includes the IP address of ...
4
votes
0answers
525 views

Why does Torbutton circuit view not consistently show the correct exit node?

Making an arbitrary number of new identities will eventually cause the circuit view in Torbutton to show the wrong exit node. This is a screenshot I took to show the problem. Notice Torbutton thinks ...
4
votes
0answers
79 views

How to know the number of circuits through my Tor relay(OR)? [duplicate]

Can anyone tell me how to know how many circuits are being build through my Tor relay(OR)? I am using vidalia.
3
votes
2answers
1k views

Stem: How to get current in-use circuit?

I am able to list the circuits, but for some reason I'm never able to quite get a circuit alone consistently, there always appears to be many of them with state BUILT. This is especially true after I ...
3
votes
1answer
200 views

Which protocol has the better perfomance TAP or NTor

Just wondering, which protocol, TAP or NTor is less computationally intensive for a relay to process and why ? Thanks Rich
3
votes
2answers
1k views

Can Tor change circuit while accessing a webpage?

In that case, it should download the page from the beginning because the TCP connection was closed, right? If it's not the case, how does Tor know when the site has finished loading?
3
votes
1answer
739 views

How to assign a stream to a circuit?

I have a Python script that is configured to connect to 4 different onion services (call them a, b, c, d), and return a value on a page. I'd like to ensure that I create separate circuits to connect ...
3
votes
2answers
2k views

How to prevent a circuit from changing between browser tabs?

In the current versions of Tor (4.5.1) every time a new tab is opened a new circuit is made - causing the ip to change. Consider the following scenarion: User logs into firstsite.com - session/...
3
votes
1answer
386 views

Changing in the relay selection in Tor source code

I want to change the Tor relay selection in the SOURCE CODE, I want to tell Tor to select my selected relays in each time it needs to build a circuit instead of randomly selected relays. I know that ...
3
votes
1answer
8k views

Tor Browser Bundle (TBB) new circuit versus new identity

I have experimented in the Tor Browser Bundle with the Tor Button's choices of "new circuit for this site" and "new identity". "New circuit" appears to affects only the open tab and creates a new ...
3
votes
3answers
202 views

Login to site.com, request “New Tor circuit for this site”, site.com still recognizes original login

Using TorBrowser, login with username and password on site.com (e.g., google, amazon, etc.), then ask TorBrowser for "New Tor circuit for this site." Why does site.com (sometimes) recognize this "new ...
3
votes
1answer
6k views

Is the Tor browser always using at Tor ciruit?

I'm using the Tor browser (4.5.3) and when I press the green onion I can see the current Tor circuit that's in use at the moment. Now, is the browser always using a Tor circuit? Because sometimes when ...
3
votes
1answer
2k views

What is the relationship between guard nodes and bridges?

What is the relationship between guard nodes and bridges when building Tor circuits? If I connect to the Tor network through a bridge, is the bridge acting as my guard node (such that there are still ...
3
votes
1answer
39 views

Why is the HS not using the RP as the Endpoint of its rendezvous circuit?

Im asking myself, why the rendezvous circuit has a minimum length of 6 hops, which are: Client -> (a1) -> (a2) -> (RP) <- (b3) <- (b2) <- (b1) <- HS The Client is using RP ...
3
votes
1answer
130 views

How a client maintains a list of guard nodes, from among hundreds of guard nodes, for creating a circuit?

It is said that a client maintains a list of guard nodes for certain time for making a circuit. I want to know how many number of guard nodes they make in a list? How often they change these guard ...
3
votes
1answer
487 views

How to implement the modified source code of Tor?

I want to log how many circuits have been made through my Tor onion router (OR). So if I do some changes in the original source code, how can I make my Tor use that changed source code. I am now using ...