07-12, 16:00–16:50 (US/Eastern), Marillac Auditorium
TLS is not as universal as we might think! To this day, extremely popular Chinese applications use home-rolled network cryptography. Mona, Jeff, and Zoë have been reverse-engineering various home-rolled cryptography that protects hundreds of millions of users' sensitive data. They'll present various case studies from the past several years, including but not limited to: MMTLS, the custom cryptographic protocol that governs all WeChat traffic; various network encryption schemes used by popular Chinese keyboard apps; and flawed cryptography found in popular Chinese browsers. Their research found that faulty cryptography in multiple browsers and keyboard apps - each with hundreds of millions of users - effectively exposed every site visited and every keystroke made to any network eavesdropper. After studying and reporting the (often severe) flaws in these schemes, the companies mostly switched to standard cryptography like TLS.
The presentation will end with a call to action for hackers to help study the network encryption ecosystem in China, which continues to be overlooked by the modern security community.
Jeffrey Knockel is a senior research associate at the Citizen Lab. In his research, he seeks to bring transparency to censorship, surveillance, and other harmful software behavior.
Mona Wang is a PhD candidate in the Center for IT Policy at Princeton University and a former EFF technologist. She studies network security with a focus on the Chinese mobile application ecosystem.
Zoë Reichert is an undergraduate research assistant at the Citizen Lab at the University of Toronto's Munk School of Global Affairs and Public Policy. Her interests include security research and tech policy.
