TOR | Achieving Internet Anonymity

I don't remember how I first heard about TOR. But then I was forced to use it. No! not because I wanted to send a threat mail to the govt, but because I wanted to download stuff off a web drive that refused me downloads due to my IP. Since TOR masks your IP (among other neat things it does), I guessed I could fool the download servers into thinking that I was someone else. IT WORKED!!!

That's when TOR really got me interested. been using it since 2005 and am continually amazed at how the system works (thanks EFF!!). So here I share TOR with you today. While its a great system, I would discourage you from testing it on a Govt agency. I will not take responsibility if you get yourself implicated ;)

So hHere's how TOR does its stuff

Though it looks pretty simple, its not! The system is so secure that even a person running a rogue TOR node will not be able to track the origin of the request no matter how sophisticated packet analysis he is capable of. For a low-down on how this beautiful system works, you can listen to Steve's Podcast (Security Now - Episode 70). I have pasted part of the show notes below.


[EXTRACTED FROM STEVE GIBSON'S SESSION WITH LEO LAPORTE]

TOR is something that interests a lot of people. We talked about the vulnerability of using a single proxy as an anonymizer because in fact traffic analysis, while complicated, like in cryptographic terms it’s trivial. If you take the case of one user using a proxy, it’s obvious who they are and what sites they’re visiting because anything they do is being done on their behalf by the proxy. Okay, so now that’s easy. Now two users are using the proxy. Well, it’s a little more difficult. But by looking at the timing of the arrival and departure of packets and the relative sizes of the packets, you could still probably disambiguate the actions of two users across a single proxy.

So knowing that, this notion of a network of proxies was created. And that’s what TOR is. TOR stands for The Onion Router.

So we start with a massive network of onion router nodes. Somebody wants to create a connection through this network to a remote server. They want to use it for web surfing, they want to use it for sending messages, for email or whatever. The TOR system, which is in its second generation now, is a general purpose TCP conduit. So instead of being protocol-specific, for example like a proxy might be an HTTP web proxy and proxying web requests, the onion router system is a general purpose TCP transmission system, so you’re able to potentially run any protocols through it that you want to. The originator of a connection chooses at random some number of onion routers that are in the network. And these things, since there’s nearly a thousand of them, they’re scattered far and wide all over the globe.

[Read more at http://www.grc.com/sn/SN-070.htm]