What Tor Is Good For
If you want to be anonymous—say, if you live under a dictatorship, you're a journalist in an oppressive country, or a hacker looking to stay hidden from the government—Tor is one of the easiest ways to anonymize your traffic, and it's free. It's far from perfect, though (we'll get to that in a moment).
On a more general level, Tor is useful for anyone who wants to keep their internet activities out of the hands of advertisers, ISPs, and web sites. That includes people getting around censorship restrictions in their country, police officers looking to hide their IP address, or anyone else who doesn't want their browsing habits linked to them.
Tor's technology isn't just about browsing anonymously. It can also host web sites through its hidden services that are only accessible by other Tor users. It's on one of these hidden service sites that something like The Silk Road exists to traffic drugs. Tor's hosting capabilities tend to pop up in police reports for things like child pornography and arms trading, too.
How does Tor work?
Now that you know what Tor is, let’s look at how it works — and how to use it.
Using Tor is relatively easy. You simply download and install the Tor Browser, which would replace Chrome, Firefox, or whatever browser you normally use. Anything you do on the Tor browser is then private and secure.
Tor bundles your data into encrypted packets before it enters the network. Tor then removes the part of the packet that contains information like the source, size, destination, and timing, all of which can be used to learn about the sender (that’d be you.) Next, it encrypts the rest of the bundled information before finally sending the encrypted data through many different servers, or relays, at random so that it can’t be tracked.
Each relay decrypts and then re-encrypts just enough data to know where it came from and where it’s going next, but can’t track the information beyond that. The many layers of encryption Tor uses to ensure anonymity are similar to an onion, hence the name. The illustration below is a good (albeit very simplified) explanation of how Tor works.
