2025-zohaib-quic-sni
Exposing and Circumventing SNI-based QUIC Censorship of the Great Firewall of Chinacore
Abstract
We expose the GFW's mechanism for SNI-based censorship of QUIC and
HTTP/3 traffic. We characterize the inspection and blocking strategy,
identify implementation flaws that the GFW's QUIC censorship inherits,
and propose practical circumvention techniques exploiting those flaws.
Best Paper Award Honorable Mentions, USENIX Security 2025.
Team notes
Recent and load-bearing for any QUIC-based defense Lantern ships into
China. Documents specific implementation flaws in the GFW's QUIC
ClientHello inspection that translate directly into circumvention
hooks. If we ship Hysteria2 / a future QUIC-based outbound for CN,
the design has to reckon with this paper's threat model.