RECENT PUBLICATIONS

1. Anna Harbluk Lorimer,  Rob Jansen, and Nick Feamster:

   Extended abstract: Traffic Splitting for Pluggable Transports. Workshop on Free and Open Communication on the Internet, 2024.

   pdf abs bib details

   As censors continue to develop more advanced technologies to police access to the Internet, new techniques are also needed to promote Internet freedom. Traffic splitting is one technique that has been shown to defend against various privacy attacks and to improve network performance, but it has not been evaluated in the context of censorship-resistant systems. In this extended abstract we outline a design for traffic splitting for pluggable transports that uses what we call a "shim" pluggable transport and modified Tor Bridges as proxies. We describe our hypotheses and how we plan to evaluate our implementation to determine the extent to which pluggable transports that employ traffic splitting can improve performance, protect against website fingerprinting attacks, and improve resistance to detection and blocking by a censor.

   @misc{ptsplit-foci2024,
     title = {Traffic Splitting for Pluggable Transports},
     author = {Lorimer, Anna Harbluk and Jansen, Rob and Feamster, Nick},
     howpublished = {Workshop on Free and Open Communication on the Internet},
     year = {2024},
     note = {Extended abstract},
   }

2. Ryan Wails, George Arnold Sullivan, Micah Sherr, and Rob Jansen:

   On Precisely Detecting Censorship Circumvention in Real-World Networks. Network and Distributed System Security Symposium, 2024.

   pdf abs bib details

   The understanding of realistic censorship threats enables the development of more resilient censorship circumvention systems, which are vitally important for advancing human rights and fundamental freedoms. We argue that current state-of-the-art methods for detecting circumventing flows in Tor are unrealistic: they are overwhelmed with false positives (> 94%), even when considering conservatively high base rates (10^-3). In this paper, we present a new methodology for detecting censorship circumvention in which a deep-learning flow-based classifier is combined with a host-based detection strategy that incorporates information from multiple flows over time. Using over 60,000,000 real-world network flows to over 600,000 destinations, we demonstrate how our detection methods become more precise as they temporally accumulate information, allowing us to detect circumvention servers with perfect recall and no false positives. Our evaluation considers a range of circumventing flow base rates spanning six orders of magnitude and real-world protocol distributions. Our findings suggest that future circumvention system designs need to more carefully consider host-based detection strategies, and we offer suggestions for designs that are more resistant to these attacks.

   @inproceedings{precisedetect-ndss2024,
     title = {On Precisely Detecting Censorship Circumvention in Real-World Networks},
     author = {Wails, Ryan and Sullivan, George Arnold and Sherr, Micah and Jansen, Rob},
     booktitle = {Network and Distributed System Security Symposium},
     year = {2024},
     doi = {10.14722/ndss.2024.23394},
   }

3. Ryan Wails,  Rob Jansen, Aaron Johnson, and Micah Sherr:

   Proteus: Programmable Protocols for Censorship Circumvention. Workshop on Free and Open Communication on the Internet, 2023.

   pdf abs bib details

   We present the Proteus system for censorship circumvention. Proteus provides a programmable protocol environment in which new communication protocols can be expressed as concise and comprehensible specification files. This design allows clients and proxies to quickly respond to new censorship strategies just by installing new specification files. Proteus improves on prior programmable designs by improving host safety from malicious specifications, providing a specification language that is complete and comprehensible to non-specialists, and supporting multiple simultaneous protocols at a proxy for versioning and localization. This paper represents work in progress and provides an overview of the Proteus design, as well as examples showing that it can express existing encrypted protocols.

   @inproceedings{proteus-foci2023,
     title = {Proteus: Programmable Protocols for Censorship Circumvention},
     author = {Wails, Ryan and Jansen, Rob and Johnson, Aaron and Sherr, Micah},
     booktitle = {Workshop on Free and Open Communication on the Internet},
     year = {2023},
   }