David Freeman

Anti-Abuse Research Scientist/Engineer
Meta Platforms, Inc.

Email: dfreeman [at] cs [dot] stanford [dot] edu

Mailing Address:
1 Hacker Way
Menlo Park, CA 94025
USA

LinkedIn Profile    CV    Publications    Presentations    Teaching    Travel Schedule    Other activities

Current Position

I am a research scientist/engineer at Meta (formerly Facebook), focusing on abuse problems. I'm currently a Tech Lead on the External Data Misuse team. I previously led various anti-abuse engineering and data science teams at LinkedIn.

Topics I care about from both a practical and research standpoint include:

• Social network abuse (fake and compromised accounts; fake engagement; spam)
• Scraping and bot detection
• Adversarial Machine Learning
• Measurement and experimentation for abuse problems

My book on Machine Learning and Security contains everything I know about the topic (as of late 2017).

If you want to learn more, you can look at some of my overview talks:

• My Enigma 2020 talk describes good and bad approaches to measuring abuse on the internet.
• My ScAINet 2018 talk presents some of the challenges in using machine learning for security in the real world.
• My Enigma 2016 talk shows some approaches to protecting accounts from being taken over.
• My Strata 2015 talk gives an overview of the kinds of anti-abuse systems I work on.

Research publications coming out of my work at Meta:

• Real Attackers Don't Compute Gradients: Bridging the Gap Between Adversarial ML Research and Practice, to appear at SaTML 2023.
• Deep Entity Classification: Abusive Account Detection for Online Social Networks, appeared at Usenix Security 2021.
• Towards a User-Level Understanding of IPv6 Behavior, appeared at IMC 2020.
• Evaluating Changes to Fake Account Verification Systems, appeared at RAID 2020.
• Shim Shimmeny: Evaluating the Security and Privacy Contributions of Link Shimming in the Modern Web, appeared at Usenix Security 2020.
• DELF: Safeguarding deletion correctness in Online Social Networks, appeared at Usenix Security 2020.

Research publications coming out of my work at LinkedIn:

• Protecting Social Network Users from Impersonation, accepted to WWW 2018.
• Can you spot the fakes? On the limitations of user feedback in online social networks, appeared at WWW 2017.
• Who are you? A statistical approach to measuring user authenticity, appeared at NDSS 2016.
• Detecting Clusters of Fake Accounts in Online Social Networks, appeared at AISec 2015.
• Using Naive Bayes to Detect Spammy Names in Social Networks, appeared at AISec 2013.

Other works in progress (v1.0 released December 26, 2010; v2.0 released April 10, 2014).

Academic Work

I was previously a postdoctoral scholar in the Applied Cryptography Group at Stanford University, under the supervision of Dan Boneh.

My thesis and postdoctoral research focused on cryptographic applications of number theory and arithmetic geometry. Projects included elliptic and hyperelliptic curve cryptography, pairing-based systems, and lattice-based cryptography.

Amongst my research interests were:

• Functional encryption from LWE (latest paper).
• Homomorphic signatures:
  Most recent work.
  Full version of the Eurocrypt 2011 paper.
  Slides from a recent talk.
• Lattice-based cryptography.
• Public-key cryptosystems based on pairings.
• Constructing pairing-friendly abelian varieties.
• "Alternative" pairings in cryptography.

I received my Ph.D. in Mathematics from the University of California, Berkeley. My Ph.D. advisors were Ken Ribet (UC Berkeley) and Ed Schaefer (Santa Clara University).

In 2009 I was an NSF postdoctoral fellow at CWI, Amsterdam and Universiteit Leiden under the supervision of Ronald Cramer.

Conferences

I have been involved with the following conferences and workshops:

• Program Committee: CCS 2022 (Los Angeles, USA), November 2022.
• Program Committee: Usenix Security 2022 (Boston, USA), August 2022.
• Program Committee: Usenix Security 2021 (virtual), August 2021.
• Program Committee: Usenix Security 2020 (virtual), August 2020.
• Steering Committee/Program Committee: AISec 2019 (London, UK), November 2019.
• Organizer: Fighting Abuse @Scale (Menlo Park, USA), November 2019.
• Steering Committee/Program Committee: ScAINet 2019 (Santa Clara, USA), August 2019.
• Program Committee: Usenix Security 2019 (Santa Clara, USA), August 2019.
• Program Committee: Deep Learning and Security 2019 (San Francisco, USA), May 2019.
• Program Committee: Enigma 2019 (Burlingame, USA), Janurary 2019.
• Program Co-Chair: AISec 2018 (Toronto, Canada), October 2018.
• Organizer: Fighting Abuse @Scale (San Francisco, USA), April 2018.
• Program Co-Chair: AISec 2017 (Dallas, USA), November 2017.
• Program Co-Chair: AISec 2016 (Vienna, Austria), October 2016.
• Program Committee: eCrime 2016 (Toronto, Canada), June 2016.
• Program Committee: Enigma 2016 (San Francisco, USA), January 2016.
• Program Committee: AISec 2015 (Denver, USA), October 2015.
• Program Committee: Pairing 2012 (Cologne, Germany), May 2012.
• Program Committee: Financial Cryptography and Data Security 2012 (Bonaire, Netherlands Antilles), February-March 2012.
• Scientific Committee: ECC 2011 (Nancy, France), September 2011.
• Program Committee: Pairing 2010 (Yamanaka Hot Spring, Japan), December 2010.
• Organizer: Public Key Cryptography and the Geometry of Numbers (Amsterdam, Netherlands), May 2010.
• Program Committee: Pairing 2009 (Stanford, USA), August 2009.

Publications

Papers Published or Submitted

1. Real Attackers Don't Compute Gradients: Bridging the Gap Between Adversarial ML Research and Practice
   Giovanni Apruzzese, Hyrum S. Anderson, Savino Dambra, David Freeman, Fabio Pierazzi, and Kevin Roundy
   To appear in IEEE Conference on Secure and Trustworthy Machine Learning --- SaTML 2023 (Raleigh, USA, February 2023).
   Published version (.pdf), Supplementary material (website).

2. Deep Entity Classification: Abusive Account Detection for Online Social Networks
   Teng Xu, Gerard Goossen, Huseyin Kerem Cevahir, Sara Khodeir, Yingyezhe Jin, Frank Li, Shawn Shan, Sagar Patel, David Freeman, and Paul Pearce
   In Usenix Security 2021 (virtual, August 2021).
   Published version (.pdf)

3. Towards A User-Level Understanding of IPv6 Behavior
   Frank Li and David Freeman
   In IMC 2020 (virtual, October 2020).
   Published version (.pdf)

4. Evaluating Changes to Fake Account Verification Systems
   Fedor Kozlov, Isabella Yuen, Jakub Kowalczyk, Daniel Bernhardt, David Freeman, Paul Pearce, and Ivan Ivanov
   In RAID 2020 (virtual, October 2020).
   Published version (.pdf)

5. Can You Spot the Fakes? On the Limitations of User Feedback in Online Social Networks
   David Mandell Freeman
   In WWW 2017 (Perth, Australia, April 2017).
   Published version (.pdf)

6. Who are you? A statistical approach to measuring user authenticity
   David Mandell Freeman, Sakshi Jain, Markus Dürmuth, Battista Biggio, and Giorgio Giacinto
   In NDSS 2016 (San Diego, USA, February 2016).
   Published version (.pdf)

7. Detecting Clusters of Fake Accounts in Online Social Networks
   Cao Xiao, David Mandell Freeman, and Theodore Hwa
   In AISec 2015 (Denver, USA, October 2015), ACM (2015).
   Published version (.pdf)

8. Using Naive Bayes to Detect Spammy Names in Social Networks
   David Mandell Freeman
   In AISec 2013 (Berlin, Germany, November 2013), ACM (2013) 3-12.
   Published version (.pdf)

9. Improved security for linearly homomorphic signatures: A generic framework
   David Mandell Freeman
   In Public Key Cryptography -- PKC 2012 (Darmstadt, Germany, May 2012), Springer LNCS 7293 (2012), 697-714.
   Download full version (.pdf)

10. Functional encryption for inner product predicates from learning with errors
    Shweta Agrawal, David Mandell Freeman, and Vinod Vaikuntanathan
    In Advances in Cryptology -- Asiacrypt 2011 (Seoul, Korea, December 2011), Springer LNCS 7073 (2011), 21-40.
    Download full version (.pdf)

11. Homomorphic signatures for polynomial functions
    Dan Boneh and David Mandell Freeman
    In Advances in Cryptology -- Eurocrypt 2011 (Tallinn, Estonia, May 2011), Springer LNCS 6632 (2011), 149-168.
    Download full version (.pdf)

12. Deniable encryption with negligible detection probability: An interactive construction
    Markus Dürmuth and David Mandell Freeman
    In Advances in Cryptology -- Eurocrypt 2011 (Tallinn, Estonia, May 2011), Springer LNCS 6632 (2011), 610-626.
    Download full version (.pdf)

    Subsequent to the publication of the above work in Eurocrypt 2011, it was shown that the main theorem in the paper is incorrect. A description of the problem appears in the Foreword to the full version.

13. Constructing pairing-friendly hyperelliptic curves using Weil restriction
    David Mandell Freeman and Takakazu Satoh
    Journal of Number Theory 131:5 (May 2011), 959-983.
    Download (.pdf)

14. Homomorphic signatures over binary fields and new tools for lattice-based signatures
    Dan Boneh and David Mandell Freeman
    In Public Key Cryptography -- PKC 2011 (Taormina, Italy, March 2011), Springer LNCS 6571 (2011), 1-16.
    Download full version (.pdf)

15. Limitations on transformations from composite-order to prime-order groups: The case of round-optimal blind signatures
    Sarah Meiklejohn, Hovav Shacham, and David Mandell Freeman
    In Advances in Cryptology -- Asiacrypt 2010 (Singapore, December 2010), Springer LNCS 6477 (2010), 519-538.
    Download full version (.pdf)

16. Converting pairing-based cryptosystems from composite-order groups to prime-order groups
    David Mandell Freeman
    In Advances in Cryptology -- Eurocrypt 2010 (French Riviera, May 2010), Springer LNCS 6110 (2010), 44-61.
    Download full version (.pdf)

17. Preventing pollution attacks in multi-source network coding
    Shweta Agrawal, Dan Boneh, Xavier Boyen, and David Mandell Freeman
    In Public Key Cryptography -- PKC 2010 (Paris, France, May 2010), Springer LNCS 6056 (2010), 161-176.
    Download (.pdf)

18. More constructions of lossy and correlation-secure trapdoor functions
    David Mandell Freeman, Oded Goldreich, Eike Kiltz, Alon Rosen, and Gil Segev
    In Public Key Cryptography -- PKC 2010 (Paris, France, May 2010), Springer LNCS 6056 (2010), 279-295.
    Download full version (.pdf)

19. A taxonomy of pairing-friendly elliptic curves
    David Freeman, Michael Scott, and Edlyn Teske
    Journal of Cryptology 23 (2010), 224-280.
    Download published version (.pdf)

20. On the security of pairing-friendly abelian varieties over non-prime fields
    Naomi Benger, Manuel Charlemagne, and David Mandell Freeman
    In Pairing-Based Cryptography -- Pairing 2009 (Palo Alto, California, August 2009), Springer LNCS 5671 (2009), 52-65
    Download (.pdf)

21. Signing a subspace: Signatures for network coding
    Dan Boneh, David Freeman, Jonathan Katz, and Brent Waters
    In Public-Key Cryptography -- PKC 2009 (Irvine, California, March 2009), Springer LNCS 5443 (2009), 68-87
    Download full version (.pdf)

22. A generalized Brezing-Weng method for constructing pairing-friendly ordinary abelian varieties
    David Freeman
    In Pairing-Based Cryptography -- Pairing 2008 (Egham, United Kingdom, September 2008), Springer LNCS 5209 (2008), 146-163
    Download (.pdf); Download additional examples (.pdf)

23. Abelian varieties with prescribed embedding degree
    David Freeman, Peter Stevenhagen and Marco Streng
    In Algorithmic Number Theory Symposium -- ANTS-VIII (Banff, Canada, May 2008), Springer LNCS 5011 (2008), 60-73.
    Download (.pdf)

24. Constructing pairing-friendly genus 2 curves with ordinary Jacobians
    David Freeman
    In Pairing-Based Cryptography -- Pairing 2007 (Tokyo, Japan, July 2007), Springer LNCS 4575, (2007), 152-176
    Download full version (.pdf)

25. Computing endomorphism rings of Jacobians of genus 2 curves over finite fields
    David Freeman and Kristin Lauter
    In Symposium on Algebraic Geometry and its Applications (Papeete, Tahiti, May 2007), World Scientific, 2008, 29-66
    Download (.pdf)

26. Constructing pairing-friendly elliptic curves with embedding degree 10
    David Freeman
    In Algorithmic Number Theory Symposium -- ANTS-VII (Berlin, Germany, July 2006), Springer LNCS 4076 (2006), 452-465
    Download (.pdf)

27. The isoperimetric problem on singular surfaces
    Andrew Cotton, David Freeman, Andrei Gnepp, Ting Ng, John Spivack, and Cara Yoder
    Journal of the Australian Mathematical Society 78:2 (April 2005) 167-199
    Download (.pdf)

28. The double bubble problem in spherical and hyperbolic space
    Andrew Cotton and David Freeman
    International Journal of Mathematics and Mathematical Sciences 32:11 (15 Dec 2002), 641-699
    Download (.pdf)

Other Papers

• Constructing abelian varieties for pairing-based cryptography
  David Freeman
  Ph.D. Dissertation, University of California, Berkeley, May 2008
  Download (.pdf)

• Pairing-based identification schemes
  David Freeman
  Hewlett-Packard Laboratories technical report HPL-2005-154, August 2005
  Download (.pdf)

• Fast arithmetic and pairing evaluation on genus 2 curves
  David Freeman
  Preprint, March 2005
  Download (.pdf)

• Applications of modular forms
  David Freeman
  Cambridge University Part III Essay, May 2003
  Download (.pdf)

Presentations

• The Abuse Uncertainty Principle, and Other Lessons Learned from Measuring Abuse on the Internet
  Contributed talk at Enigma 2020, San Francisco, California, January 2020.
  Slides (.pdf); Presentation Video

• Adversarial ML in Real Life: Examples, Lessons, and Challenges
  Invited talk at King's College London workshop on "AI for Security and the Security of AI," London, United Kingdom, January 2020
  Slides (.pdf)

• "You can't just turn the crank": Machine learning for fighting abuse on the consumer web
  Invited talk at ScAINet 2018, Atlanta, Georgia, May 2018.
  Slides (SlideShare)

• Can you spot the fakes? On the limitations of user feedback in online social networks
  Contributed talk at WWW 2017, Perth, Australia, April 2017.
  Slides (.pdf)

• Server-Side Second Factors: Approaches to Measuring User Authenticity
  Contributed talk at Enigma 2016, San Francisco, California, January 2016.
  Slides (SlideShare) Video

• Data Science vs. the Bad Guys: Using Data to Defend Linkedin From Fraud and Abuse
  Contributed talk at Strata 2015, San Jose, California, February 2015.
  Slides (SlideShare)

• Using Naive Bayes to Detect Spammy Names in Social Networks
  Contributed paper at AISec 2013, Berlin, Germany, November 2013.
  Slides (.pdf)

• Improved security for linearly homomorphic signatures: A generic framework
  Contributed paper at PKC 2012, Darmstadt, Germany, May 2012.
  Slides (.pdf)

• Functional encryption for inner product predicates from learning with errors
  Contributed paper at Asiacrypt 2011, Seoul, Korea, December 2011.
  Slides (.pdf)

• Homomorphic signatures: Message integrity for network coding and beyond
  Invited talk at Workshop on Beyond Worst-Case Analysis, Stanford, California, September 2011.
  Slides (.keynote)

• Homomorphic signatures for polynomial functions
  Cryptography Seminar at IBM Research, Hawthorne, NY, November 2010.
  Theory Seminar at UC San Diego, San Diego, CA, November 2010.
  Theory Seminar at Microsoft Research Silicon Valley, December 2010.
  Séminaire de Crypto de l'ENS, Paris, France, March 2011.
  Eurocrypt 2011, Tallinn, Estonia, May 2011.
  Information Security Group Research Seminar, Royal Holloway University of London, July 2011.
  Slides: long version, short version (.pdf)

• Homomorphic signatures over binary fields and new tools for lattice-based signatures
  Contributed paper at PKC 2011, Taormina, Italy, March 2011.
  Slides (.pdf)

• Converting pairing-based cryptosystems from composite-order groups to prime-order groups
  Contributed paper at Eurocrypt 2010, Monaco, May 2010.
  Slides (.pdf)

• More constructions of lossy and correlation-secure trapdoor functions
  Contributed paper at PKC 2010, Paris, France, May 2010.
  Slides (.pdf)

• Pairing-friendly hyperelliptic curves and Weil restriction
  Contributed talk at Workshop on Discovery and Experimentation in Number Theory, Toronto, Canada, September 2009.
  Poster at ANTS-IX, Nancy, France, July 2010.
  Slides: full version, short version; Poster (.pdf)

• Signing a linear subspace: Signatures for Network Coding
  Contributed talk at IPAM Securing Cyberspace Reunion Conference, Lake Arrowhead, CA, June 2009
  Slides: .pdf, .keynote

• Constructing abelian varieties for pairing-based cryptography
  Invited talk at Workshop on Pairings in Arithmetic Geometry and Cryptography, Essen, Germany, May 2009.
  Slides (.pdf)

• A generalized Brezing-Weng method for constructing pairing-friendly ordinary abelian varieties
  Contributed paper at Pairing 2008, Egham, United Kingdom, September 2008.
  Slides (.pdf)

• Constructing abelian varieties for pairing-based cryptography.
  Invited talk at Computational Number Theory Workshop, Foundations of Computational Mathematics 2008, Hong Kong, June 2008
  Slides (.pdf)

• Implementing the genus 2 CM method
  Invited talk at AMS Special Session on Low Genus Curves and Applications, AMS-MAA Joint Mathematics Meetings, San Diego, CA, January 2008.
  Slides (.pdf)

• Constructing pairing-friendly genus 2 curves with ordinary Jacobians
  Contributed paper at Pairing 2007, Tokyo, Japan, July 2007
  Slides (.pdf)

• Constructing Pairing-Friendly Elliptic Curves for Cryptography
  Invited talk at the 2nd KIAS-KMS Summer Workshop on Cryptography, Seoul, Korea, June 2007.
  Slides Part 1, Part 2 (.pdf)

• Methods for constructing pairing-friendly elliptic curves.
  Invited talk at the 10th Workshop on Elliptic Curves in Cryptography (ECC 2006), Toronto, Canada, September 2006.
  Slides (.pdf)

• Constructing pairing-friendly elliptic curves with embedding degree 10.
  Contributed paper at ANTS-VII, Berlin, Germany, July 2006.
  Slides (.pdf)

• Qualifying exam
  Taken to advance to doctoral candidacy at UC Berkeley, May 2005
  Syllabus (.pdf)

In Fall 2011 I taught Elliptic Curves in Cryptography (CS 259C/Math 250) at Stanford.
Course web page.

In Fall 2007 I was a Graduate Student Instructor for Math 16a at Berkeley, taught by Jack Wagoner.
Section web page.

In Fall 2005 I was a Graduate Student Instructor for Math 1a at Berkeley, taught by Vaughan Jones.
Section web page.

• Studentenkoor Amsterdam
• UC Berkeley University Chorus.
• University of California Alumni Chorus.
• Cal Cycling.
• Harvard Radio Broadcasting (WHRB).
• Ask Torrey
• See what I used to do in my spare time, back when I had some.
• See what I now do all the time.
• Fact Tree Enterprises web sites:
  • ClassicalCDGuide.com: This site recommends classical music CDs, with lists of the Top 10 CDs and Top 20 CDs, and recommendations by composer, era, and genre. The site is very extensive, and the reviews are extremely detailed. Great for a beginner or someone looking to expand his or her collection!
  • SailingCourseGuide.com: This guide provides general advice for anyone in the U.S. who wants to sign up for a sailing course, including tips on how to choose between schools and warning signs of problematic programs.

Last updated 28 Dec 2022.