Research

A general theme of my research is designing protocols to provide good, provable tradeoffs between privacy and utility. Specifically, I am working on private data publishing and anonymous communication protocols.

In private data publishing I am interested in exploring and applying formal notions of privacy. In particular, I am interested in applying differential privacy to concrete problems in data publishing.

The goal of my work on anonymous communication protocols is to formally specify them and rigorously analyze their properties. In particular, I am interested in provably good tradeoffs between anonymity, latency, and message complexity.

My other interests involve other areas of computer science theory, including computational finance, algorithmic game theory, privacy protocols, and probabilistic analysis of algorithms and protocols.

Publications

  1. PeerFlow: Secure Load Balancing in Tor [pdf] [BibTeX]
    Aaron Johnson, Rob Jansen, Nicholas Hopper, Aaron Segal, and Paul Syverson
    In Proceedings on Privacy Enhancing Technologies (PoPETS 2017), Vol. 2017, Number 2, April 2017.
    Show abstract
  2. Avoiding The Man on the Wire: Improving Tor's Security with Trust-Aware Path Selection [pdf] [BibTeX]
    • Technical Report (Full Version) [pdf] [BibTeX]
    Aaron Johnson, Rob Jansen, Aaron D. Jaggard, Joan Feigenbaum, and Paul Syverson
    In Proceedings of the 24th Network and Distributed System Security Symposium (NDSS 2017).
    Show abstract
  3. Safely Measuring Tor [pdf] [BibTeX]
    Rob Jansen and Aaron Johnson
    In Proceedings of the 23rd ACM Conference on Computer and Communications Security (CCS 2016).
    Show abstract
  4. Defending Tor from Network Adversaries: A Case Study of Network Path Prediction [pdf] [BibTeX]
    Joshua Juen, Aaron Johnson, Anupam Das, Nikita Borisov, and Matthew Caesar
    In Proceedings on Privacy Enhancing Technologies (PoPETS 2015), Vol. 2015, Number 2, June 2015.
    Show abstract
  5. Hidden-service statistics reported by relays [pdf] [BibTeX]
    David Goulet, Aaron Johnson, George Kadianakis, and Karsten Loesing
    Tor Technical Report 2015-04-001, April 2015.
    Media coverage of resulting statistics: BBC News, Ars Technica
    Show abstract
  6. 20,000 In League Under the Sea: Anonymous Communication, Trust, MLATs, and Undersea Cables [pdf] [BibTeX]
    Aaron D. Jaggard, Aaron Johnson, Sarah Cortes, Paul Syverson, and Joan Feigenbaum
    In Proceedings on Privacy Enhancing Technologies (PoPETS 2015), Vol. 2015, Number 1, April 2015.
    Show abstract
  7. Security Analysis of Accountable Anonymity in Dissent [pdf] [BibTeX]
    • Technical Report (Full Version) [pdf] [BibTeX]
    Ewa Syta, Aaron Johnson, Henry Corrigan-Gibbs, Shu-Chun Weng, David Wolinsky, and Bryan Ford
    In ACM Transactions on Information and System Security (TISSEC), Volume 17, Issue 1, Article No. 4, August 2014.
    Show abstract
  8. The Sniper Attack: Anonymously Deanonymizing and Disabling the Tor Network [pdf] [BibTeX]
    Rob Jansen, Florian Tschorsch, Aaron Johnson, and Björn Scheuermann
    In Proceedings of the 21st Network and Distributed System Security Symposium (NDSS 2014).
    Show abstract
  9. Users Get Routed: Traffic Correlation on Tor by Realistic Adversaries [pdf] [BibTeX]
    Aaron Johnson, Chris Wacek, Rob Jansen, Micah Sherr, and Paul Syverson
    In Proceedings of the 20th ACM Conference on Computer and Communications Security (CCS 2013).
    Media coverage: The Register, Vice, The Irish Times, Ars Technica, Finnish Broadcasting Company (YLE), NewScientist, MIT Technology Review
    Show abstract
  10. Privacy-Preserving Data Exploration in Genome-Wide Association Studies
    Aaron Johnson and Vitaly Shmatikov
    In Proceedings of the 19th ACM SIGKDD Conference on Knowledge Discovery and Data Mining (KDD 2013).
    Show abstract
  11. Poster: Onions for Sale: Putting Privacy on the Market [pdf] [ppt]
    Aaron Johnson, Rob G. Jansen, and Paul Syverson
    In Proceedings of the 17th International Conference on Financial Cryptography and Data Security (FC 2013).
    Show abstract
  12. LIRA: Lightweight Incentivized Routing for Anonymity [pdf] [BibTeX]
    Rob G. Jansen, Aaron Johnson, and Paul Syverson
    In Proceedings of the 20th Network and Distributed System Security Symposium (NDSS 2013).
    Show abstract
  13. Dissent in Numbers: Making Strong Anonymity Scale [pdf] [BibTeX]
    David Isaac Wolinsky, Henry Corrigan-Gibbs, Bryan Ford, and Aaron Johnson
    In Proceedings of the Tenth USENIX Symposium on Operating Systems Design and Implementation (OSDI '12).
    Show abstract
  14. Probabilistic Analysis of Onion Routing in a Black-box Model [pdf] [BibTeX]
    Joan Feigenbaum, Aaron Johnson, and Paul Syverson
    In ACM Transactions on Information and System Security (TISSEC), Volume 15 Issue 3, November 2012.
    Show abstract
  15. Scalable Anonymous Group Communication in the Anytrust Model [pdf] [BibTeX]
    David Isaac Wolinsky, Henry Corrigan-Gibbs, Bryan Ford, and Aaron Johnson
    In Proceedings of the Fifth European Workshop on System Security (EuroSec 2012).
    Show abstract
  16. Trust-based Anonymous Communication: Adversary Models and Routing Algorithms [pdf] [BibTeX]
    Aaron Johnson, Paul Syverson, Roger Dingledine, and Nick Mathewson
    In Proceedings of the 18th ACM Conference on Computer and Communications Security (CCS 2011).
    Show abstract
  17. Preventing Active Timing Attacks in Low-Latency Anonymous Communication (Extended Abstract) [pdf] [BibTeX]
    Joan Feigenbaum, Aaron Johnson, and Paul Syverson
    In Proceedings of the 10th Privacy Enhancing Technologies Symposium (PETS 2010).
    Show abstract
  18. More Anonymous Onion Routing Through Trust [pdf] [BibTeX]
    Aaron Johnson and Paul Syverson
    In Proceedings of the 22nd IEEE Computer Security Foundations Symposium (CSF 2009).
    Show abstract
  19. Online and Offline Selling in Limit Order Markets [pdf] [BibTeX]
    Kevin L. Chang and Aaron Johnson
    In Proceedings of the 4th International Workshop on Internet and Network Economics (WINE 2008).
    Show abstract
  20. Probabilistic Analysis of Onion Routing in a Black-box Model (Extended abstract) [pdf] [BibTeX]
    Joan Feigenbaum, Aaron Johnson, and Paul Syverson
    In Proceedings of the 2007 ACM Workshop on Privacy in Electronic Society (WPES 2007).
    Show abstract
  21. Private Web Search [pdf] [BibTeX] [software]
    Felipe Saint-Jean, Aaron Johnson, Dan Boneh, and Joan Feigenbaum
    In Proceedings of the 2007 ACM Workshop on Privacy in Electronic Society (WPES 2007).
    Show abstract
  22. A Model of Onion Routing with Provable Anonymity [pdf] [BibTeX]
    Joan Feigenbaum, Aaron Johnson, and Paul Syverson
    In Proceedings of Financial Cryptography and Data Security '07 (FC 2007).
    Show abstract

Talks

  1. PeerFlow: Secure Load Balancing in Tor [ppt]
    At the 17th Privacy Enhancing Technologies Symposium (PETS 2017).
    July 18, 2017. Minneapolis, MN.
  2. Privacy-Preserving Measurement of the Tor Network [ppt]
    Invited talk at the Center for Disclosure Avoidance Research, U.S. Census.
    May 30, 2017. U.S. Census, Washington, DC.
  3. Avoiding The Man on the Wire: Improving Tor's Security with Trust-Aware Path Selection [ppt]
    At the 24th Network and Distributed System Security Symposium.
    February 28, 2017. San Diego, CA.
  4. Improving Tor's Security with Trust-Aware Path Selection [ppt]
    Invited talk at the Tulane University Computer Science Colloquium.
    January 30, 2017. Tulane University, New Orleans, LA.
  5. Private Measurement of Tor
    Invited talk at the Workshop: Theory and Practice of Secure Multiparty Computation 2016.
    June 2, 2016. Aarhus University, Aarhus, Denmark.
  6. Location-Aware Onion Routing [ppt] [pdf]
    Short talk at the 36th IEEE Symposium on Security and Privacy.
    May 19, 2015. San Jose, CA.
  7. Users Get Routed: Traffic Correlation on Tor by Realistic Adversaries [ppt]
    Invited talk at the Max Planck Institute for Software Systems.
    July 29, 2013. MPI-SWS, Saarbrücken, Germany.
  8. LIRA: Lightweight Incentivized Routing for Anonymity [ppt]
    At the 20th Network and Distributed System Security Symposium.
    February 27, 2013. San Diego, CA.
  9. Onion Routing Security Analysis [ppt]
    At the DC-Area Anonymity, Privacy, and Security Seminar.
    January 18, 2012. University of Maryland, College Park, MD.
  10. Proving Security in Dissent [ppt]
    At the DC-Area Anonymity, Privacy, and Security Seminar.
    October 26, 2012. Georgetown University, Washington, DC.
  11. Anonymity Analysis of Onion Routing in the Universally Composable Framework [ppt]
    At the Provable Privacy Workshop.
    July 9, 2012. Vigo, Spain.
  12. Trust-based Anonymous Communication: Adversary Models and Routing Algorithms [ppt]
    At the 18th ACM Conference on Computer and Communications Security (CCS 2011).
    October 19, 2011. Chicago, IL.
  13. Preventing Active Timing Attacks in Low-Latency Anonymous Communication [ppt]
    At the 10th Privacy Enhancing Technologies Symposium (PETS 2010).
    July 22, 2010. Berlin, Germany.
  14. More Anonymous Onion Routing Through Trust [ppt]
    At the 22nd IEEE Computer Security Foundations Symposium (CSF 2009).
    July 8, 2009. Port Jefferson, New York.
  15. Online and Offline Selling in Limit Order Markets [ppt]
    At the 4th International Workshop on Internet and Network Economics (WINE 2008).
    December 17, 2008. Shanghai, China.
  16. Towards a Theory of Onion Routing [ppt]
    Invited talk, Department of Electrical and Computer Engineering, Iowa State University.
    May 27, 2008. Iowa State University, Ames, Iowa.
  17. A Probabilistic Analysis of Onion Routing in a Black-box Model [ppt]
    At the 2007 ACM Workshop on Privacy in the Electronic Society (WPES 2007).
    October 29, 2007. Alexandria, VA.
  18. A Formal Analysis of Onion Routing [ppt]
    At the Protocol Exchange Seminar.
    October 26, 2007. University of Maryland, Baltimore County, MD.
  19. A Model of Onion Routing with Provable Anonymity [ppt]
    At the 11th Financial Cryptography and Data Security Conference (FC 2007).
    February 12, 2007. Lowlands, Scarborough, Trinidad/Tobago.

Education

Yale University, New Haven, CT U.S.A.
  • Ph.D., Computer Science, December 2009
    Dissertation advisor: Professor Joan Feigenbaum
    Dissertation: Design and Analysis of Efficient Anonymous-Communication Protocols
  • M.S., Computer Science, May 2005
Northwestern University, Evanston, IL U.S.A.
  • B.S. cum laude with honors, Computer Science, June 2004
    Honors thesis advisor: Professor Ming-Yang Kao
    Honors thesis: Routing Network Flow Among Selfish Agents

Employment

September, 2011 - present Computer scientist / Security theorist
Formal Methods Section
Center for High Assurance Computer Systems
United States Naval Research Laboratory
Washington, DC
September, 2009 - August, 2011 Postdoctoral fellow
Department of Computer Science
The University of Texas at Austin
Austin, TX
Advisor: Prof. Vitaly Shmatikov

Service

Organizer

Editorial Board

Program Committee Member

External Reviewer

  • Conferences: CRYPTO 2016, IEEE S&P 2015, USENIX Security 2014, PETS 2014, CSF 2013, IEEE S&P 2013, NDSS 2013, CCS 2012, NDSS 2012, CSF 2011, ESA 2011, ICALP 2010, IFIP SEC 2010, IEEE S&P 2010, ESORICS 2009, PODC 2009, WWW 2009, PETS 2008
  • Journals: ACM Transactions on Networking (TON), ACM Transactions on Internet Technology (TOIT), IEEE Transactions on Information Theory, Proceedings on Privacy Enhancing Technologies (PoPETs), ACM Transactions on Information and System Security (TISSEC), IEEE Transactions on Dependable and Secure Computing (TDSC), Journal of Computer Security (JCS), Cambridge Journals: Mathematical Structures in Computer Science (MSCS)

Awards

  • 47th Annual Alan Berman Research Publication Award
    To be awarded April 17th, 2015, by the U.S. Naval Research Laboratory
    For best paper in the Information Technology Division:
    The Sniper Attack: Anonymously Deanonymizing and Disabling the Tor Network
    In Proceedings of the 21st Annual Network & Distributed System Security Symposium (NDSS '14).
  • 44th Annual Alan Berman Research Publication Award
    Awarded March 16th, 2012, by the U.S. Naval Research Laboratory
    For best paper in the Information Technology Division:
    Trust-based Anonymous Communication: Adversary Models and Routing Algorithms
    In Proceedings of the 18th ACM Conference on Computer and Communications Security (CCS 2011).