Great Firewall Report

What We Do

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GFW Report is a long-term censorship monitoring platform, aiming at advancing the understanding and spreading the awareness of Internet censorship. Our platform has a primary focus on the Internet censorship in China as it is one of the most repressive censoring regimes that has been developing and deploying notoriously sophisticated censorship techniques.

News

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September 2025:

• Geedge & MESA Leak: Analyzing the Great Firewall’s Largest Document Leak

August 2025:

• USENIX Security'25: Exposing and Circumventing SNI-based QUIC Censorship of the Great Firewall of China
• Analysis of the GFW's Unconditional Port 443 Block on August 20, 2025

May 2025:

• S&P'25: A Wall Behind A Wall: Emerging Regional Censorship in China

February 2025:

• NDSS'25: Wallbleed: A Memory Disclosure Vulnerability in the Great Firewall of China

November 2023:

• Many Popular Censorship Circumvention Tools Deleted or Archived since November 2, 2023

October 2023:

• The blocking of 1.1.1.1 in China, starting from 2023-10-01

April 2023:

• USENIX SECURITY'23: How the Great Firewall of China Detects and Blocks Fully Encrypted Traffic

October 2022:

• Sharing a modified Shadowsocks
• Sharing our thoughts on the cat-and-mouse game
• Sharing a Trojan-go with updated uTLS fingerprints
• Large scale blocking of TLS-based censorship circumvention tools in China
• The Great Firewall of China has blocked google.com and all its subdomains

September 2021:

• Evaluating the censorship resistance of Apple's iCloud Private Relay
• Reflections on Apple's iCloud Private Relay: Does it Really Improve Privacy?

January 2021:

• How to Deploy a Censorship Resistant Shadowsocks-libev Server
• A practical guide to defend against the GFW's latest active probing

October 2020:

• IMC'20 Paper: How China Detects and Blocks Shadowsocks
• IMC'20 Talk: How China Detects and Blocks Shadowsocks

August 2020:

• FOCI'20: Triplet Censors: Demystifying Great Firewall’s DNS Censorship Behavior

August 2020:

• Exposing and Circumventing China's Censorship of ESNI

June 2020:

• Summary on Recently Discovered V2Ray Weaknesses

March 2020:

• GFW Archaeology: gfw-looking-glass.sh

December 2019:

• Report: How China Detects and Blocks Shadowsocks