Hardware Reference
In-Depth Information
Understanding Tor bridges
In 2006, in response to an increased Internet censorship, the Tor project added an anti-
censorship feature called a bridge relay or simply, a bridge (Dingledine, 2006). A bridge is
a special form of a relay—it's not listed in the public relay directory. Strong Internet cen-
sors were able to block access to Tor through several methods. One method that was effect-
ive was to look up all the public relays, which were only a thousand or so at the time, and
deny access to those IP addresses. Therefore, bridge relays were created and distributed by
less public means in order to allow users to access the Tor network. If a client could access
the bridge, which was already connected to Tor, then the client could access the Internet. In
this context, less public means a distribution mechanism that does not work via the public
relay list.
