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

Automated Discovery of Cross-Plane Event-Based Vulnerabilities in Software-Defined Networking

Benjamin E. Ujcich (University of Illinois at Urbana-Champaign), Samuel Jero (MIT Lincoln Laboratory), Richard Skowyra (MIT Lincoln Laboratory), Steven R. Gomez (MIT Lincoln Laboratory), Adam Bates (University of Illinois at Urbana-Champaign), William H. Sanders (University of Illinois at Urbana-Champaign), Hamed Okhravi (MIT Lincoln Laboratory)

Read More

Secure Sublinear Time Differentially Private Median Computation

Jonas Böhler (SAP Security Research), Florian Kerschbaum (University of Waterloo)

Read More

Snappy: Fast On-chain Payments with Practical Collaterals

Vasilios Mavroudis (University College London), Karl Wüst (ETH Zurich), Aritra Dhar (ETH Zurich), Kari Kostiainen (ETH Zurich), Srdjan Capkun (ETH Zurich)

Read More

µRAI: Securing Embedded Systems with Return Address Integrity

Naif Saleh Almakhdhub (Purdue University and King Saud University), Abraham A. Clements (Sandia National Laboratories), Saurabh Bagchi (Purdue University), Mathias Payer (EPFL)

Read More