DEF CON 30 - Roger Dingledine - How Russia is trying to block Tor

In December 2021, some ISPs in Russia started blocking Tor's website, along with protocol-level (DPI) and network-level (IP address) blocking to try to make it harder for people in Russia to reach the Tor network. Some months later, we're now at a steady-state where they are trying to find new IP addresses to block and we're rotating IP addresses to keep up. In this talk I'll walk through what steps the Russian censors have taken, and how we reverse engineered their attempts and changed our strategies and our software. Then we'll discuss where the arms race goes from here, what new techniques the anti-censorship world needs if we're going to stay ahead of future attacks, and what it means for the world that more and more countries are turning to network-level blocking as the solution to their political problems.