THE article discusses a significant leak of over 100,000 internal files from Geedge Networks, revealing parts of the Tiangou Secure Gateway (TSG), a commercial censorship platform developed to detect and block VPNs. Researchers reconstructed TSG from the leaked source code, establishing links to China's Great Firewall through its traffic filtering mechanisms and handling of DNS queries. The leak is noted as the first source code disclosure of a deep packet inspection censorship system.
Internal documents indicate TSG's deployments in Myanmar, Pakistan, and Ethiopia. The platform's functionalities include traffic throttling, connection severing, and tracking capabilities, with development influenced by customer requests, particularly to manage specific applications like Signal. Ethical concerns have restricted access to the leaked code, only available to vetted researchers.