Today, we observe an increasing prevalence of satellite Internet solutions, powered by the launch of LEO (low Earth orbit) satellite constellations such as Starlink and OneWeb. These solutions have largely facilitated the provisioning of Internet access to users residing in remote regions, and continue to be enhanced through the launch of more capable satellites and upgrades to routing algorithms within the constellations themselves. While promising connectivity speeds similar to fiber networks, LEO satellite Internet makes use of wireless mediums which are known to be prone to several sources of interference. It remains unclear, however, what implications these recent satellite networking environments may have on the privacy of users, especially when considering adversaries with the ability to eavesdrop and analyze the metadata of Internet connections that are partly or entirely established via satellite links.
We aim to shed light on whether LEO satellite Internet users are more vulnerable to website fingerprinting attacks than users using traditional fiber. To this end, we set up an experimental testbed including both a fiber and Starlink connection, and use them to collect a dataset of synchronized website accesses over Tor. We leverage state-of-the-art website fingerprinting attacks over our collected traces to understand whether network adversaries able to inspect the ground links between users and the first hop of both kinds of connections (like a snooping satellite ISP) can identify which websites are being accessed by users. Lastly, we evaluate the security benefits and performance trade-offs of website fingerprinting defenses when applied to fiber and satellite Internet links.
Our findings suggest that Tor traffic exchanged over Starlink Internet links is equally vulnerable to website fingerprinting attacks as Tor traffic exchanged over traditional fiber links. We hypothesize that, despite the different connectivity characteristics of the ground satellite link that connects our measurement node to the Tor network, most of the interference experienced in this link is absorbed by the network effects (e.g., added latency, jitter, etc.) inherent to Tor circuits.
Our paper, tools, and datasets can be found below.
(SpaceSec 2024) Connecting the Dots in the Sky: Website Fingerprinting in Low Earth Orbit Satellite Internet. Prabhjot Singh, Diogo Barradas, Tariq Elahi, Noura Limam.
We deliver the following main contributions:
Our Starlink node at the University of Waterloo is setup as part of LEOScope.