10 March 2025 - Rob Jansen

Speaker:

Rob Jansen

Title:

Repositioning Real-World Website Fingerprinting on Tor with a Measurement of Genuine Tor Traces

Abstract:

Website fingerprinting (WF) is a potentially devastating attack against Tor because it can break anonymity by linking a Tor user to their purportedly unlinkable internet destinations. In this talk, we will explore WF by an adversary whose classifiers are tested against real-world entry traces that are naturally created by real Tor users. With this task in mind, we will explore a novel pre-training method that an adversary can employ that will allow it to utilize real-world in-distribution data measured by Tor exit relays in order to train classifiers that are more effective in the real world. To produce more accurate WF estimates, we measure and construct the first WF dataset of genuine Tor traces, called GTT23, and use it to train and test more than 3,500 WF classifiers. Our results suggest that real-world WF is more challenging than previously understood and that WF studies that exclusively use synthetic datasets may broadly overestimate WF performance.

Bio:

Dr. Rob Jansen is a Computer Scientist and a Jerome and Isabella Karle Distinguished Scholar at the U.S. Naval Research Laboratory. He developed the Shadow network simulator and is an expert in Tor network modeling and simulation. He currently studies methods for traffic analysis and traffic obfuscation, and has extensively studied Tor performance problems, scalability improvements, incentives for growing the network, and resource and routing attacks. Rob focuses on transitioning research to practice: Shadow has become the standard tool for simulating Tor networks and is used by the Tor Project and at dozens of universities worldwide; his KIST traffic scheduler is the default method for transferring Tor’s traffic; and his programmable Proteus system enables the rapid development censorship evasion protocols. Rob currently serves as a program co-chair for the Proceedings on Privacy Enhancing Technologies (PoPETs), and generally serves on numerous security and privacy focused academic committees, including for USENIX Security, ACM CCS, PoPETs, and FOCI, and has served on the Tor Research Safety Board since its inception in 2016.