Sandra Siby (EPFL), Marc Juarez (University of Southern California), Claudia Diaz (imec-COSIC KU Leuven), Narseo Vallina-Rodriguez (IMDEA Networks Institute), Carmela Troncoso (EPFL)

Virtually every connection to an Internet service is preceded by a DNS lookup which is performed without any traffic-level protection, thus enabling manipulation, redirection, surveillance, and censorship. To address these issues, large organizations such as Google and Cloudflare are deploying recently standardized protocols that encrypt DNS traffic between end users and recursive resolvers such as DNS-over-TLS (DoT) and DNS-over-HTTPS (DoH). In this paper, we examine whether encrypting DNS traffic can protect users from traffic analysis-based monitoring and censoring. We propose a novel feature set to perform the attacks, as those used to attack HTTPS or Tor traffic are not suitable for DNS’ characteristics. We show that traffic analysis enables the identification of domains with high accuracy in closed and open world settings, using 124 times less data than attacks on HTTPS flows. We find that factors such as location, resolver, platform, or client do mitigate the attacks performance but they are far from completely stopping them. Our results indicate that DNS-based censorship is still possible on encrypted DNS traffic. In fact, we demonstrate that the standardized padding schemes are not effective. Yet, Tor — which does not effectively mitigate traffic analysis attacks on web traffic— is a good defense against DoH traffic analysis.

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DISCO: Sidestepping RPKI's Deployment Barriers

Tomas Hlavacek (Fraunhofer SIT), Italo Cunha (Universidade Federal de Minas Gerais), Yossi Gilad (Hebrew University of Jerusalem), Amir Herzberg (University of Connecticut), Ethan Katz-Bassett (Columbia University), Michael Schapira (Hebrew University of Jerusalem), Haya Shulman (Fraunhofer SIT)

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Practical Traffic Analysis Attacks on Secure Messaging Applications

Alireza Bahramali (University of Massachusetts Amherst), Amir Houmansadr (University of Massachusetts Amherst), Ramin Soltani (University of Massachusetts Amherst), Dennis Goeckel (University of Massachusetts Amherst), Don Towsley (University of Massachusetts Amherst)

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MassBrowser: Unblocking the Censored Web for the Masses, by...

Milad Nasr (University of Massachusetts Amherst), Hadi Zolfaghari (University of Massachusetts Amherst), Amir Houmansadr (University of Massachusetts Amherst), Amirhossein Ghafari (University of Massachusetts Amherst)

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Automated Cross-Platform Reverse Engineering of CAN Bus Commands From...

Haohuang Wen (The Ohio State University), Qingchuan Zhao (The Ohio State University), Qi Alfred Chen (University of California, Irvine), Zhiqiang Lin (The Ohio State University)

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