Tor over QUIC

Tor is the most popular tool for anonymous online communication. However, the performance of Tor's volunteer-run network is suboptimal when network congestion occurs. Within Tor, many connections are multiplexed over a single TCP connection between relays, which causes a head-of-line blocking problem, degrading relay performance. In this thesis, Tor's TCP transport layer protocol is replaced by QUIC, a UDP-based protocol that natively supports multiplexing streams asynchronously, effectively solving head-of-line blocking. Its performance is evaluated within various network environments through Containernet, a flexible Docker-based network test bed that allows for simple reproduction of results. Along with testing multiple congestion control algorithms, the impact of using Hystart++ within Tor over QUIC is evaluated. It is found that QUIC over Tor can perform up to 50% better in time to last byte performance than vanilla Tor in a realistic network environment, while featuring more consistent time to first byte performance. Additionally, the evaluations shows that throughput consistency and fairness amongst downloaders are improved as well, Besides offering improved performance, Tor over QUIC is designed with deployability and security in mind. This makes QUIC an attractive replacement as Tor's transport layer protol.Computer Scienc