2025-wu-regional-censorship
A Wall Behind A Wall: Emerging Regional Censorship in Chinacore
Abstract
We characterize a previously-unknown class of GFW deployment: regional
censorship that operates inside China and applies different blocklists
to different provinces. We focus on Henan province, where additional
censorship is layered on top of the national GFW. The findings
challenge the longstanding "national GFW" mental model of CN
censorship and have implications for measurement methodology.
Team notes
Important mental-model update: CN censorship is not monolithic. Lantern
measurement methodology that bins all CN traffic together loses signal;
the bandit's per-ASN dimensioning already partially addresses this but
province-level effects suggest we need finer geo dimensioning for CN
in particular. If we see anomalous CN bandit signals concentrated in
one province, this paper is the first place to look.