Dr Gareth Owen: TOR - Attacks and Countermeasures

Tor is an anonymisation network which allows users to browse the internet without their true IP address being identified. Tor also allows those in countries who censor the internet to bypass that censorship both by allowing users to access censored sites and to host websites which would otherwise land them in jail if it were possible to trace them. Initially, I will talk about how Tor works explaining the infrastructure and high-level protocol. I will also introduce Tor Hidden Services, untraceable websites, and how this service is provided within the network. Briefly, I then touch on the Silk Road and Freedom hosting hidden sites. Secondly, I will talk about I will explain how countries such as China and Iran have attempted to block Tor and what steps have been taken to minimise this. I will also explain attacks against the Tor users and network infrastructure that have been developed in academia (and the community) along with defences that can be deployed to minimise the risks. Finally, I will cover how the FBI took down Silk Road and delivered an exploit that was able to deanonymise visitors to Tor hidden services -- covering the Firefox exploit and shellcode.