The Tor Project unveiled its latest anti-censorship tool called WebTunnel, a Tor bridge that operates as a concealed server that remains unlisted in Tor's public directory. These bridges, being discreet, are commonly utilized in repressive regions to enable users to access the Tor network.
Over the past twenty years, Tor bridges have relied on protocols like obfs3 and obfs4 to encrypt and disguise traffic, evading firewall and censorship measures.
The WebTunnel censorship-resistant pluggable transport method emulates encrypted web traffic, inspired by HTTPT. The tool achieves its goal by wrapping the connection payload within a WebSocket-like HTTPS connection. This process makes it indistinguishable from standard HTTPS (WebSocket) connections to network observers. This means that to an outside observer unaware of its existence, WebTunnel traffic appears as regular HTTP traffic to a webpage server, creating the illusion of typical web browsing activity.
For most Tor Browser users, WebTunnel can serve as a viable alternative to obfs4. While obfs4 and similar fully encrypted traffic aim for complete anonymity, WebTunnel's strategy of mimicking familiar web traffic renders it more effective in environments featuring a protocol allow list and a deny-by-default network setup.
The team said that while WebTunnel works in regions like China and Russia, it does not currently work in some regions in Iran.
The instructions on how to download and use a WebTunnel Bridge can be found in The Tor Project’s blog post.
