conference logo

Playlist "32C3: gated communities"

How the Great Firewall discovers hidden circumvention servers

Philipp Winter

Several years ago, the Great Firewall of China was silently upgraded to find and block circumvention servers that employ encryption to defeat deep packet inspection. The system is now used to block protocols such as Tor, SoftEther, and SSH. In this talk, we will give an overview of how this system works, and how it can be circumvented.