Roya Ensafi

Email:  rensafi[@] [pgp]

Here is my CV and bio.

My research focuses on security and privacy, with an emphasis on designing techniques and systems to protect users from hostile networks. Much of my work has focused on detecting and defending against adversaries who manipulate Internet traffic in order to block, monitor, or otherwise tamper with users' online activities.

I am a postdoc at Princeton University in the Computer Science Department and the Center for Information Technology Policy (CITP). My frequent collaborators include Nick Feamster, Vern Paxson, Jennifer Rexford, Jed Crandall, and the Tor Project.

Selected Projects

I have worked on several networking-related research projects, mainly in:

1. Network Interference:

  • Studying national firewalls, especially the Great Firewall of China (GFW). In a collaborative effort, we detected and documented the Great Cannon that shows China’s capabilities for active man-in-the-middle attacks. More recently, we investigated how the GFW’s active probing system is designed, which is used to discover and block hidden circumvention proxies.
  • Capturing a global view on Internet censorship, with Censored Planet, an ongoing project and platform to measure both IP and DNS censorship, without controlling any vantage points. Censored Planet allows us to regularly collect “censorship snapshots” of 143 countries, a scale that has never been achieved before. For more, take a look at our project page.
  • Developing effective side channels (a.k.a. idle scans) for measuring how information flows between two remote hosts around the world, without requiring any kind of distributed measurement platform or access to any of the machines from which connectivity is tested. Spooky Scan— a.k.a hybrid idle scan—is among three side channels that I designed and developed over years. We used the Spooky Scan and a side channel in the Linux kernel’s SYN backlog to measure the reachability of the Tor network (which is known to be blocked in China) over space and time. For more, please have a look at our project page. Currently, we are using this technique to capture the global state of Internet reachability. For more, read my USENIX paper or listen to my talk.

2. Privacy Preserving Technologies:

  • Characterizing and avoiding routing detours through surveillance states. We are investigating how the use of overlay networks and the DNS open resolver infrastructure can prevent traffic from traversing certain jurisdictions. In collaboration with A. Edmundson, N. Feamster, and J. Rexford. For more, take a look at our project page.
  • Understanding the security and privacy risks of the Internet of Things. We are developing a testbed to reveal vulnerabilities and privacy leaks based on automated analysis of traffic from smart-home devices. Our findings have led to patches and informed FTC policy. In collaboration with S. Grover and N. Feamster. For more, read our blog post.

Selected Publications

The full list of my publications is available here.


  • I will serve as a program committee member for USENIX-Security'17 , IMC'17.
  • I attended the 2016 Rising Stars Workshop at CMU!
  • I gave a lecture about surveillance and circumvention at MIT in October :)
  • I finished my reviews for NSF, IMC'16, PETS’16, PAM’16, CoNEXT’16, and FOCI'16.
  • I gave a talk at the Berkman Center at Harvard University (May 2016).
  • I finished a lecture on privacy & surveillance for a networking class & a Netseminar talk about the GFW at Stanford University (April 2016).
  • Our team was among the winners in the CAIDA BGP Hackathon 2016.
  • I won the Applied Networking Research Prize, IRTF 2016.
  • We are organizing a Conference on Internet Censorship, Interference, and Control at CITP.
  • I served as a panelist for FOCI’15 (August 2015).
  • I attended the NSF NeTS Early Career Workshop (July 2015).
  • I presented our PETS’15 paper in Philadelphia, PA (April 2016).


  • Applied Networking Research Prize, Internet Research Task Force, 2016
  • 2016 Rising Stars Invitee, CMU/MIT
  • Granted an NSF NeTS Early Career Workshop award, 2015
  • Passed with Distinction Award for PhD dissertation, CS, UNM, December 2014
  • Excellence in Graduate Research, Sigma Xi, UNM, 2014
  • Graduate Student Mentor Award, UNM, 2011–2012
  • Graduate Student Highlight, CS, UNM, January 2011
  • MEP Fellowship, School of Engineering Scholarship, UNM, Fall 2009