TOR Browser - Everything you need to know before using TOR.

We live in an era of free-flowing data, where any person with an Internet connection has seemingly all the information in the world at their fingertips. Yet, while the Internet has greatly expanded the ability to share knowledge, it has also made issues of privacy more complicated, with many worrying their own personal information, including their activity on the Internet, may be observed without their permission. Not only are government agencies able to track an individual’s online movements, but so too are corporations, who have only become bolder in using that information to target users with ads. Unseen eyes are everywhere.

TorProject.org

Not too many computer users have heard of the terms "proxy" or "proxy server," or understand what they mean or do. A proxy server is a website/server that acts as a middleman for you to get on the Internet. When you use a proxy server, you're not contacting a website directly—your information runs through a special computer that passes along your request for you.

But more than that, a proxy packages your request with a different "identifier." In other words, your IP address is no longer visible; instead, your request borrows the IP address of the proxy.

 

Have you ever wanted to browse the Internet anonymously? The truth is that browser settings such as "incognito mode" or "private window" don't quite cut it. If you want real anonymity, you're going to want to use Tor, formerly known as The Onion Router that has become the subject of discussion and notoriety. Like many underground phenomena on the Internet, it is poorly understood, shrouded in the sort of technological mysticism that people often ascribe to things like hacking or bitcoins.

Tor is software that allows users to browse the Web anonymously. Developed by the Tor Project, a non-profit organization that advocates for anonymity on the internet, Tor was originally called The Onion Router because it uses a technique called onion routing to conceal information about user activity. Perhaps ironically, the organization receives the bulk of its funding from the United States government, which views Tor as a tool for fostering democracy in authoritarian states. 

What is TOR?

Tor is short for The Onion Router (thus the logo) and was initially a worldwide network of servers developed with the U.S. Navy that enabled people to browse the internet anonymously. Tor is a free software program that you load onto your computer (like a browser) that hides your IP address every time you send or request data on the Internet. The process is layered with heavy-duty encryption, which means your data is layered with privacy protection.

The Tor network disguises your identity by moving your traffic across different Tor servers, and encrypting that traffic so it isn't traced back to you. Anyone who tries would see traffic coming from random nodes on the Tor network, rather than your computer.

To access this network, you just need to download the Tor browser. Everything you do in the browser goes through the Tor network and doesn't need any setup or configuration from you. That said, since your data goes through a lot of relays, it's slow, so you'll experience a much more sluggish internet than usual when you're using Tor.

How TOR works?

The Tor network runs through the computer servers of thousands of volunteers (over 4,500 at time of publishing) spread throughout the world. Your data is bundled into an encrypted packet when it enters the Tor network. Then, unlike the case with normal Internet connections, Tor strips away part of the packet's header, which is a part of the addressing information that could be used to learn things about the sender such as the operating system from which the message was sent.

Finally, Tor encrypts the rest of the addressing information, called the packet wrapper. Regular Internet connections don't do this. 

The modified and encrypted data packet is then routed through many of these servers, called relays, on the way to its final destination.The roundabout way packets travel through the Tor network is akin to a person taking a roundabout path through a city to shake a pursuer.

Each relay decrypts only enough of the data packet wrapper to know which relay the data came from, and which relay to send it to next. The relay then re-wraps the package in a new wrapper and sends it on.

The layers of encrypted address information used to anonymize data packets sent through Tor are reminiscent of an onion, hence the name. That way, a data packet's path through the Tor network cannot be fully traced.

Some regular Internet data packets are encrypted using a protocol called Secure Socket Layer (SSL) or its newer, stronger cousin Transport Layer Security (TLS). For example, if you submit your credit card information to an online store, that information travels across the network in an encrypted state to prevent theft.

However, even when you use SSL or TLS, it's still possible for others to intercept those packets and see the information's metadata — who sent that encrypted information and who received it — because the addressing wrappers in SSL or TLS are not encrypted. In Tor, they are, which hides the sender and receiver of a given transmission.

Further, if you use the Tor Browser to visit a website that does not use encryption to secure users' connections, then your data packet will not be encrypted when it makes the final hop from the last Tor relay to the website's server. That's because the data packet's destination lies outside the Tor network. So it's best to be sure that a website offers some kind of SSL or TLS encryption, usually denoted by an "https" instead of simply "http" in the Web address, before trying to access it anonymously.

Is Tor secure?

Good question! Security and anonymity go hand in hand on the Internet. As an online anonymizer, Tor was designed to be secure.

However, documents leaked by former National Security Agency (NSA) contractor Edward Snowden show that the NSA has tried to crack, infiltrate or weaken any encryption that the agency does not itself control.

In light of this news, nearly all independent encryption and online communication services have become suspect, including Tor.

"The online anonymity network Tor is a high-priority target for the National Security Agency," cryptography expert Bruce Schneier, who is helping British newspaper The Guardian analyze its archive of leaked Snowden documents, wrote in a piece for the newspaper.

But despite this warning, another Snowden document published by The Guardian suggests that the NSA can't crack Tor after all, although the agency has developed some workarounds.

"We will never be able to de-anonymize all Tor users all the time," reads the document, a PowerPoint presentation used internally at the NSA and its British equivalent GCHQ.

Instead, the NSA exploited a vulnerability in Firefox browsers (on which the Tor Browser is based) to monitor individual users' Tor activity. That vulnerability has since been patched in Firefox and recent Tor Browser Bundle updates.

"The good news is that they went for a browser exploit, meaning there's no indication they can break the Tor protocol or do traffic analysis on the Tor network," wrote The Tor Project on its blog in response to The Guardian's article.

"Tor still helps here: you can target individuals with browser exploits, but if you attack too many users, somebody's going to notice. So even if the NSA aims to surveil everyone, everywhere, they have to be a lot more selective about which Tor users they spy on."