Linux Hardening in Hostile Networks: Server Security from TLS to Tor

Appendix A. Tor

Chapter 4, “Network,” discusses how to use Tor to protect your anonymity on a network, but it focuses more on how to use Tor and less about how Tor works. Here, I dive a bit deeper into how Tor works and how it can protect your anonymity. I also discuss some of the security risks around Tor and how you can mitigate them.

What Is Tor?

When you use the Internet, you normally use it without any promise of anonymity. You and the computers you talk to on the Internet are assigned IP addresses and every packet that goes between you and a remote server has the source and destination IP in its headers, like the address and return address on a postcard. Even if you use a protocol like TLS to encrypt your network traffic, those headers ...