When Encryption Isn’t Enough: The TLS Obscurity Approach to Defeating Censorship

Exploring the award-winning 2025 IEEE S&P research “Transport Layer Obscurity: Circumventing SNI Censorship on the TLS Layer.” The talk explains how internet censors exploit the plaintext Server Name Indication (SNI) in TLS handshakes and introduces innovative techniques that manipulate TLS behaviors to hide or disguise this information. Viewers will learn why this problem matters, how the researchers’ approach works, how effective it is in real-world censorship environments, and what new insights it offers for the future of secure, censorship-resistant communication.