Measuring Information Leakage in Website Fingerprinting Attacks and Defenses

TL;DR

This paper develops a methodology and tools to measure the amount of information leaked by website fingerprinting attacks and defenses in the Tor network, enabling detailed analysis of vulnerabilities and protection mechanisms.

Contribution

It introduces a novel measurement approach and tools for quantifying information leakage in website fingerprinting, applied across various features and defenses.

Findings

Quantifies information leakage in WF attacks

Analyzes effectiveness of different defenses

Provides detailed insights into leakage mechanisms

Abstract

Tor provides low-latency anonymous and uncensored network access against a local or network adversary. Due to the design choice to minimize traffic overhead (and increase the pool of potential users) Tor allows some information about the client's connections to leak. Attacks using (features extracted from) this information to infer the website a user visits are called Website Fingerprinting (WF) attacks. We develop a methodology and tools to measure the amount of leaked information about a website. We apply this tool to a comprehensive set of features extracted from a large set of websites and WF defense mechanisms, allowing us to make more fine-grained observations about WF attacks and defenses.