PCP: Preemptive Circuit Padding against Tor circuit fingerprinting

by   George Kadianakis, et al.

Online anonymity and privacy has been based on confusing the adversary by creating indistinguishable network elements. Tor is the largest and most-used deployed anonymity system, designed against realistic modern adversaries. Recently, researchers have managed to fingerprint Tor's circuits - and hence the type of underlying traffic - simply by capturing and analyzing traffic traces. In this work, we study the circuit fingerprinting problem, isolating it from website fingerprinting, and revisit previous findings in this model, showing that accurate attacks are possible even when the application-layer traffic is identical. We then proceed to incrementally create defenses against circuit fingerprinting, using a generic adaptive padding framework for Tor based on WTF-PAD. We present a simple but high-latency defense, as well as a more advanced low-latency one which can effectively hide onion service circuits with no additional delays. We thoroughly evaluate both defenses, both analytically and experimentally, discovering new subtle fingerprints, but also showing the effectiveness of our defenses.


page 1

page 2

page 3

page 4


This is not the padding you are looking for! On the ineffectiveness of QUIC PADDING against website fingerprinting

Website fingerprinting (WF) is a well-know threat to users' web privacy....

Towards Effective and Efficient Padding Machines for Tor

Tor recently integrated a circuit padding framework for creating padding...

RegulaTOR: A Powerful Website Fingerprinting Defense

Website Fingerprinting (WF) attacks are used by passive, local attackers...

WFDefProxy: Modularly Implementing and Empirically Evaluating Website Fingerprinting Defenses

Tor, an onion-routing anonymity network, has been shown to be vulnerable...

SurfCuit: Surface Mounted Circuits on 3D Prints

We present, SurfCuit, a novel approach to design and construction of ele...

TARANET: Traffic-Analysis Resistant Anonymity at the NETwork layer

Modern low-latency anonymity systems, no matter whether constructed as a...

Low-Latency Asynchronous Logic Design for Inference at the Edge

Modern internet of things (IoT) devices leverage machine learning infere...