Tao Wang (Hong Kong University of Science and Technology)

Tor is an anonymity network that allows clients to browse web pages privately, but loading web pages with Tor is slow. To analyze how the browser loads web pages, we examine their resource trees using our new browser logging and simulation tool, BLAST. We find that the time it takes to load a web page with Tor is almost entirely determined by the number of round trips incurred, not its bandwidth, and Tor Browser incurs unnecessary round trips. Resources sit in the browser queue excessively waiting for the TCP, TLS or ALPN handshakes, each of which takes a separate round trip. We show that increasing resource loading capacity with larger pipelines and even HTTP/2 do not decrease load time because they do not save round trips.

We set out to minimize round trips with a number of protocol and browser improvements, including TCP Fast Open, optimistic data, zero-RTT TLS. We also recommend the use of databases to assist the client with redirection, identifying HTTP/2 servers, and prefetching. All of these features are designed to cut down on the number of round trips incurred in loading web pages. To evaluate these proposed improvements, we create a simulation tool and validate that it is highly accurate in predicting mean page load times. We use the simulator to analyze these features and it predicts that they will decrease the mean page load time by 61% in total over HTTP/2. Our large improvement to user experience comes at trivial cost to the Tor network.

View More Papers

A View from the Cockpit: Exploring Pilot Reactions to...

Matthew Smith (University of Oxford), Martin Strohmeier (University of Oxford), Jonathan Harman (Vrije Universiteit Amsterdam), Vincent Lenders (armasuisse Science and Technology), Ivan Martinovic (University of Oxford)

Read More

Unicorn: Runtime Provenance-Based Detector for Advanced Persistent Threats

Xueyuan Han (Harvard University), Thomas Pasquier (University of Bristol), Adam Bates (University of Illinois at Urbana-Champaign), James Mickens (Harvard University), Margo Seltzer (University of British Columbia)

Read More

Poseidon: Mitigating Volumetric DDoS Attacks with Programmable Switches

Menghao Zhang (Tsinghua University), Guanyu Li (Tsinghua University), Shicheng Wang (Tsinghua University), Chang Liu (Tsinghua University), Ang Chen (Rice University), Hongxin Hu (Clemson University), Guofei Gu (Texas A&M University), Qi Li (Tsinghua University), Mingwei Xu (Tsinghua University), Jianping Wu (Tsinghua University)

Read More

Carnus: Exploring the Privacy Threats of Browser Extension Fingerprinting

Soroush Karami (University of Illinois at Chicago), Panagiotis Ilia (University of Illinois at Chicago), Konstantinos Solomos (University of Illinois at Chicago), Jason Polakis (University of Illinois at Chicago)

Read More