Tor is a free-software anonymizing network that helps people around the world use the Internet in safety. But who cares how good Tor’s privacy is, if your government prevents you from reaching the Tor network?
In the beginning, some countries filtered torproject.org by DNS (so we made website mirrors and an email autoresponder for downloading Tor), and then some countries blocked Tor relays by IP address (so we developed bridges, which are essentially unlisted relays), and then some countries blocked Tor traffic by Deep Packet Inspection (so we developed pluggable transports to transform Tor flows into benign-looking traffic).
Then things got weird, with China’s nationwide active probing infrastructure to enumerate bridges, with Amazon rolling over to Russia’s threats when Telegram used «domain fronting» to get around blocking, with Turkey blocking Tor traffic by DPI in more subtle ways, with Venezuela and Ethiopia and Iran trying new tricks, and more.
In this talk I’ll get you up to speed on all the ways governments have tried to block Tor, walk through our upcoming steps to stay ahead of the arms race, and give you some new—easier—ways that let you help censored users reach the internet safely.
Roger Dingledine is president and co-founder of the Tor Project, a nonprofit that develops free and open source software to protect people from tracking, censorship, and surveillance online.
Wearing one hat, Roger works with journalists and activists on many continents to help them understand and defend against the threats they face. Wearing another, he is a lead researcher in the online anonymity field, coordinating and mentoring academic researchers working on Tor-related topics. Since 2002 he has helped organize the yearly international Privacy Enhancing Technologies Symposium (PETS).
Among his achievements, Roger was chosen by the MIT Technology Review as one of its top 35 innovators under 35, he co-authored the Tor design paper that won the Usenix Security «Test of Time» award, and he has been recognized by Foreign Policy magazine as one of its top 100 global thinkers.