DNS-sly: Avoiding Censorship through Network Complexity

Authors: 

Qurat-Ul-Ann Danyal Akbar, Marcel Flores, and Aleksandar Kuzmanovic, Northwestern University

Abstract: 

We design DNS-sly, a counter-censorship system which enables a covert channel between a DNS client and server. To achieve covertness and deniability in the upstream direction, DNS-sly applies user personalization, adapting to individual behaviors. In the downstream direction, it utilizes CDN-related DNS responses to embed data, while retaining statistical covertness. We show DNS-sly achieves downstream throughput of up to 600 Bytes of raw hidden data per click on a regular Web page, making it a practical system in the context of a covert Web proxy service. We implement DNS-sly and evaluate it in a known censorship environment, demonstrating its real-world usability.

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BibTeX
@inproceedings {198588,
author = {Qurat-Ul-Ann Danyal Akbar and Marcel Flores and Aleksandar Kuzmanovic},
title = {{DNS-sly}: Avoiding Censorship through Network Complexity},
booktitle = {6th USENIX Workshop on Free and Open Communications on the Internet (FOCI 16)},
year = {2016},
address = {Austin, TX},
url = {https://www.usenix.org/conference/foci16/workshop-program/presentation/akbar},
publisher = {USENIX Association},
month = aug
}
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