Traffic flow analysis of tor pluggable transports

Tor provides the users the ability to use the Internet anonymously. On the Tor network, the users connect to three relays run by volunteers. The addresses of these relays are publicly available. Some organizations prevent access to Tor by blocking the addresses of these relays. To mitigate this, Tor has introduced the concept of bridges and pluggable transports. Bridges are relays that do not have publicly available addresses so that they can evade the blocking. Pluggable transports are used to obfuscate the connection to these bridges. In this paper, we investigate the robustness of these pluggable transports in evading the flow based traffic analysis and blocking systems.