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I downloaded the Tor Browser a decade ago, maybe even longer, in an effort to be privacy conscious. I used it here and there but I never made the switch to usin

I downloaded the Tor Browser a decade ago, maybe even longer, in an effort to be privacy conscious. I used it here and there but I never made the switch to using Tor by default. Some time later I remember reading the US government was tracking people, or had a list of everyone, who had simply downloaded Tor. I also vaguely remember reading about how using Tor could potentially expose you to legal risks because of the way the information hops between user computers. I don't really know much about networking or the nitty gritty of how Tor works so I uninstalled it. I don't know if any of that was true and even if it was I'm sure a lot has changed with how Tor handles privacy and directs traffic. Are there any good resources for average Joe internet users to read about how the browser works so I can better understand the risks/rewards?

crdrost 6y ago
I mean there are a lot of resources but they are at a very high level. I don't think much has changed. The basic idea is that with Tor, you make HTTPS connections to the "tor relay", a network of volunteers who route your traffic around the world to make it hard to track. You can use Tor in two ways: you can join the relay network and route traffic for others, or you can just use the browser and make queries. If you do decide to join the relay network you have an additional decision about whether you will be an "exit node", one that does the final request to the destination website and thus appears to be the initiator of the request. This is an option because it can be difficult on home internet setups: if someone uses your exit node to post a lot of stupid crap to Reddit and Reddit tries to IP-ban them, then you are suddenly IP-banned from Reddit at home, because you ran the exit node. If you are just a user then the only thing you need to know is that there is a price for your privacy, which is that routing your traffic all the way around the world takes a little more time than sending it straight to you, and this has two effects -- a latency jump which exists basically no matter how big the network gets, and a slowdown in your bandwidth which depends on how big the network is relative to the number of people trying to browse with it.
- zodiakzz 6y ago
  How is malicious interference by exit nodes prevented for plaint-text HTTP requests?
  - mrlala 6y ago
    I would have to say "it's not".. anything non-encrypted you risk being manipulated by a node of the TOR network. I bet there are people who act as relays just to try to sniff out any good non-HTTPS traffic.. although, I suppose generally anyone using TOR is mostly aware of this so there's probably not that much to gain. Complete side note.. but this just reminds me of back when I was in college in the late 90s, and our entire apartment buildings traffic was a hub (not a switch).. so I had a packet sniffer running for fun on linux and could see everything from everyones internet since every single packet was rounting to every machine on the network, and lots of stuff had no encryption... nuts to think how open stuff was back in the day.
    - justinclift 6y ago
      Pretty sure some switches (to this day) can be tricked into doing similar. eg send them a few specially crafted packets, and they fall back into broadcasting ~everything like a hub for some period of time. Not from the point of view of "legal intercept" stuff, more like "switch gets confused and doesn't know how to route, so broadcasts as a workaround".
  - freemint 6y ago
    It can't be prevented on a technological level. However there are attempts to detect bad nodes and ban them. Since the exit node doesn't know "who" is accessing the website it can't just temper with your content. So it would be detected asymptomatically.
  - alkyl 6y ago
    A subset of relay operators & other volunteers monitor the network for bad actors and report them to Tor Project who will then direct directory authority operators to blacklist those relays. One of those volunteers is nusenu: https://medium.com/@nusenu/the-growing-problem-of-malicious-relays-on-the-tor-network-2f14198af548 https://medium.com/@nusenu/the-growing-problem-of-malicious-...
- implements 6y ago
  > if someone uses your exit node to post a lot of stupid crap to Reddit ... I think there’s a lot more to worry about than reddit shitposts eg straight up criminal activity apparently coming from your router, and in way you’d have difficulty proving was tor and not you or your family.
seisvelas 6y ago
I highly recommend Computerphile's explanation of Onion Routing: https://www.youtube.com/watch?v=QRYzre4bf7I https://www.youtube.com/watch?v=QRYzre4bf7I After that, check out the video explaining how hidden services work. If you want to see a simple implementation of an onion router, I built one in TypeScript: https://github.com/seisvelas/onion-router-ts https://github.com/seisvelas/onion-router-ts (be warned, I also did that as an exercise to learn more TypeScript. So it's not good TS. But improvements and issues are more than welcome from any TS gurus out there!)
- vsareto 6y ago
  I think your repo is private, I get a 404
  - seisvelas 6y ago
    Indeed it was! I just made it public, thanks for saying something :)
- ralston3 6y ago
  Computerphile is truly a gift to us all
  - GEBBL 6y ago
    It’s such an unfortunate name to use though!
    - ta8347 6y ago
      Why is that?
      - tempestn 6y ago
        I assume that GEBBL is either only familiar with the -phile suffix in the context of 'pedophile', or is implying that that could be the case for others.
staycoolboy 6y ago
The Tor Browser is scrutinized heavily. I know that is kind of a fallacious argument, but they have a routine presence at DefCon and they are really committed to protecting people around the world. At DefCon last year, the Tor project talked about the biggest security concern as countries who monitor the entry points to the network, and the challenges with getting those IPs distributed confidentially and keeping them hidden. (If you don't already know, Tor does require an entry IP address list before the anonymization occurs: countries can arrest people who visit these URLs, so this is the big challenge right now.) Someone who knows more can probably elaborate, but after hearing them present year after year, and how much global advocacy they engage in, and their transparency, I find it unlikely they have NSA spooks embedded. I use it when I need to read something objectionable through a VPN. (Still not perfect, because I run a VPN on EC2 and the exit zone is in the US...) Not trying to be flame-baity here, but with Trump's ranting about making ANTIFA a terror org, and with the recent legislation that allows warrant-less IP tracking, I am legitimately concerned I might end up on a watch list because I visit a website this admin finds objectionable.
- elliekelly 6y ago
  > If you don't already know, Tor does require an entry IP address list before the anonymization occurs: countries can arrest people who visit these URLs, so this is the big challenge right now. Sorry, can you explain what this means? Would my home IP address be the "entry IP address" you're referring to?
  - rakoo 6y ago
    No, it's the IP of the first relay. Tor works pretty much like this: You -> Relay 1 -> Relay 2 -> Relay 3 -> The website Each arrow is an encrypted connection. The content of the exchange on a single arrow is the address of the next hop and the query of the next hop. Thanks to this: - Relay 1 only knows you're going through Relay 2 - Relay 2 doesn't know who's asking (you) but knows it passed through Relay 1 and is going through Relay 3 - Relay 3 doesn't know who's asking (you) and where you entered, but knows it's going to the website The nodes in the middle know everything that goes through them, but don't have the big picture. The entry IP address is the IP address of Relay 1. Your computer must know an address to connect to, and that address is distributed in listings by the Tor Project. Since this listing is public, it also makes it easier for censors to censor, or at least detect who's interested in connecting through Tor
wdrw 6y ago
If you're thinking about risks, it's important not to conflate 3 scenarios: (1) running a Tor exit node (potentially very risky), (2) running a Tor relay node, and (3) just using the Tor browser as a user (should probably be fine for most users - depends on what you use it for of course, and Tor by itself is of course not sufficient to solve all privacy issues - you can still be deanonymized if you're not careful).
- FillardMillmore 6y ago
  Do you have any more information on how one could be deanonymized using Tor? I am aware of the browser fingerprinting and Tor themselves has a decent article about it but are there other methods that malicious parties could use? https://blog.torproject.org/browser-fingerprinting-introduction-and-challenges-ahead https://blog.torproject.org/browser-fingerprinting-introduct...
  - calvinmorrison 6y ago
    Well a big one would be putting personally identifiable information on websites inside or outside the tor network.
  - michaelt 6y ago
    To use an obvious example, if you log into an account you've previously logged into directly from your home computer. More broadly, any privacy tech can be undone by poor 'operational security'. For example Ross Ulbricht - 'Dread Pirate Roberts' of Silk road - posted on StackOverflow under his own name to ask "How can I connect to a Tor hidden service using curl in php?" [1] [1] https://arstechnica.com/information-technology/2013/10/silk-road-mastermind-unmasked-by-rookie-goofs-complaint-alleges/ https://arstechnica.com/information-technology/2013/10/silk-...
badrabbit 6y ago
It's true. Same applies with Tails. If your employer is one of the few with intelligence community shadow relationships,they will likely be alerted as well. You will also be targeted for browser exploitation without a warrant. Tails in an isolated environment is probably the best way of using Tor.
kristianp 6y ago
You could use Brave browser, it includes a Tor client which is accessed through the "new private window with Tor" menu item. I assume downloads of Brave might not be tracked by the US government, but then again, everything is tracked, it's just a matter of what behavior is likely to be flagged by an agency's algorithms.

crdrost 6y ago

I mean there are a lot of resources but they are at a very high level. I don't think much has changed. The basic idea is that with Tor, you make HTTPS connections to the "tor relay", a network of volunteers who route your traffic around the world to make it hard to track. You can use Tor in two ways: you can join the relay network and route traffic for others, or you can just use the browser and make queries. If you do decide to join the relay network you have an additional decision about whether you will be an "exit node", one that does the final request to the destination website and thus appears to be the initiator of the request. This is an option because it can be difficult on home internet setups: if someone uses your exit node to post a lot of stupid crap to Reddit and Reddit tries to IP-ban them, then you are suddenly IP-banned from Reddit at home, because you ran the exit node. If you are just a user then the only thing you need to know is that there is a price for your privacy, which is that routing your traffic all the way around the world takes a little more time than sending it straight to you, and this has two effects -- a latency jump which exists basically no matter how big the network gets, and a slowdown in your bandwidth which depends on how big the network is relative to the number of people trying to browse with it.

zodiakzz 6y ago
How is malicious interference by exit nodes prevented for plaint-text HTTP requests?
- mrlala 6y ago
  I would have to say "it's not".. anything non-encrypted you risk being manipulated by a node of the TOR network. I bet there are people who act as relays just to try to sniff out any good non-HTTPS traffic.. although, I suppose generally anyone using TOR is mostly aware of this so there's probably not that much to gain. Complete side note.. but this just reminds me of back when I was in college in the late 90s, and our entire apartment buildings traffic was a hub (not a switch).. so I had a packet sniffer running for fun on linux and could see everything from everyones internet since every single packet was rounting to every machine on the network, and lots of stuff had no encryption... nuts to think how open stuff was back in the day.
  - justinclift 6y ago
    Pretty sure some switches (to this day) can be tricked into doing similar. eg send them a few specially crafted packets, and they fall back into broadcasting ~everything like a hub for some period of time. Not from the point of view of "legal intercept" stuff, more like "switch gets confused and doesn't know how to route, so broadcasts as a workaround".
- freemint 6y ago
  It can't be prevented on a technological level. However there are attempts to detect bad nodes and ban them. Since the exit node doesn't know "who" is accessing the website it can't just temper with your content. So it would be detected asymptomatically.
- alkyl 6y ago
  A subset of relay operators & other volunteers monitor the network for bad actors and report them to Tor Project who will then direct directory authority operators to blacklist those relays. One of those volunteers is nusenu: https://medium.com/@nusenu/the-growing-problem-of-malicious-relays-on-the-tor-network-2f14198af548 https://medium.com/@nusenu/the-growing-problem-of-malicious-...
implements 6y ago
> if someone uses your exit node to post a lot of stupid crap to Reddit ... I think there’s a lot more to worry about than reddit shitposts eg straight up criminal activity apparently coming from your router, and in way you’d have difficulty proving was tor and not you or your family.

seisvelas 6y ago

I highly recommend Computerphile's explanation of Onion Routing: https://www.youtube.com/watch?v=QRYzre4bf7I https://www.youtube.com/watch?v=QRYzre4bf7I After that, check out the video explaining how hidden services work. If you want to see a simple implementation of an onion router, I built one in TypeScript: https://github.com/seisvelas/onion-router-ts https://github.com/seisvelas/onion-router-ts (be warned, I also did that as an exercise to learn more TypeScript. So it's not good TS. But improvements and issues are more than welcome from any TS gurus out there!)

vsareto 6y ago
I think your repo is private, I get a 404
- seisvelas 6y ago
  Indeed it was! I just made it public, thanks for saying something :)
ralston3 6y ago
Computerphile is truly a gift to us all
- GEBBL 6y ago
  It’s such an unfortunate name to use though!
  - ta8347 6y ago
    Why is that?
    - tempestn 6y ago
      I assume that GEBBL is either only familiar with the -phile suffix in the context of 'pedophile', or is implying that that could be the case for others.

staycoolboy 6y ago

The Tor Browser is scrutinized heavily. I know that is kind of a fallacious argument, but they have a routine presence at DefCon and they are really committed to protecting people around the world. At DefCon last year, the Tor project talked about the biggest security concern as countries who monitor the entry points to the network, and the challenges with getting those IPs distributed confidentially and keeping them hidden. (If you don't already know, Tor does require an entry IP address list before the anonymization occurs: countries can arrest people who visit these URLs, so this is the big challenge right now.) Someone who knows more can probably elaborate, but after hearing them present year after year, and how much global advocacy they engage in, and their transparency, I find it unlikely they have NSA spooks embedded. I use it when I need to read something objectionable through a VPN. (Still not perfect, because I run a VPN on EC2 and the exit zone is in the US...) Not trying to be flame-baity here, but with Trump's ranting about making ANTIFA a terror org, and with the recent legislation that allows warrant-less IP tracking, I am legitimately concerned I might end up on a watch list because I visit a website this admin finds objectionable.

elliekelly 6y ago
> If you don't already know, Tor does require an entry IP address list before the anonymization occurs: countries can arrest people who visit these URLs, so this is the big challenge right now. Sorry, can you explain what this means? Would my home IP address be the "entry IP address" you're referring to?
- rakoo 6y ago
  No, it's the IP of the first relay. Tor works pretty much like this: You -> Relay 1 -> Relay 2 -> Relay 3 -> The website Each arrow is an encrypted connection. The content of the exchange on a single arrow is the address of the next hop and the query of the next hop. Thanks to this: - Relay 1 only knows you're going through Relay 2 - Relay 2 doesn't know who's asking (you) but knows it passed through Relay 1 and is going through Relay 3 - Relay 3 doesn't know who's asking (you) and where you entered, but knows it's going to the website The nodes in the middle know everything that goes through them, but don't have the big picture. The entry IP address is the IP address of Relay 1. Your computer must know an address to connect to, and that address is distributed in listings by the Tor Project. Since this listing is public, it also makes it easier for censors to censor, or at least detect who's interested in connecting through Tor

wdrw 6y ago

If you're thinking about risks, it's important not to conflate 3 scenarios: (1) running a Tor exit node (potentially very risky), (2) running a Tor relay node, and (3) just using the Tor browser as a user (should probably be fine for most users - depends on what you use it for of course, and Tor by itself is of course not sufficient to solve all privacy issues - you can still be deanonymized if you're not careful).

FillardMillmore 6y ago
Do you have any more information on how one could be deanonymized using Tor? I am aware of the browser fingerprinting and Tor themselves has a decent article about it but are there other methods that malicious parties could use? https://blog.torproject.org/browser-fingerprinting-introduction-and-challenges-ahead https://blog.torproject.org/browser-fingerprinting-introduct...
- calvinmorrison 6y ago
  Well a big one would be putting personally identifiable information on websites inside or outside the tor network.
- michaelt 6y ago
  To use an obvious example, if you log into an account you've previously logged into directly from your home computer. More broadly, any privacy tech can be undone by poor 'operational security'. For example Ross Ulbricht - 'Dread Pirate Roberts' of Silk road - posted on StackOverflow under his own name to ask "How can I connect to a Tor hidden service using curl in php?" [1] [1] https://arstechnica.com/information-technology/2013/10/silk-road-mastermind-unmasked-by-rookie-goofs-complaint-alleges/ https://arstechnica.com/information-technology/2013/10/silk-...

badrabbit 6y ago

It's true. Same applies with Tails. If your employer is one of the few with intelligence community shadow relationships,they will likely be alerted as well. You will also be targeted for browser exploitation without a warrant. Tails in an isolated environment is probably the best way of using Tor.

kristianp 6y ago

You could use Brave browser, it includes a Tor client which is accessed through the "new private window with Tor" menu item. I assume downloads of Brave might not be tracked by the US government, but then again, everything is tracked, it's just a matter of what behavior is likely to be flagged by an agency's algorithms.