I'm a researcher at BU computer science focusing on privacy, with an affiliation in the Hariri Institute. I got my PhD from Johns Hopkins University in 2020, under the supervision of my advisors Avi Rubin and Matt Green.

I am also an observant Jew and play Ultimate.

A copy of my CV is available here. A copy of my dissertation is available here.

If you came to this website expecting stuff about the placebo effect or alternative medicine, you may be looking for my father's website.


My group at JHU recently set up a website to help keep track of all the exciting new publications in applied crypto researching. While EPrint is great and all, its hard to read 1500 publications a year, especially when very few of them are applied. We call it Applied Cryptography Research: A Board aka ACRAB. Check it out! Make an account and help out!



  • Fluid MPC: Secure Multiparty Computation with Dynamic Participants.
      Arka Rai Choudhuri, Aarushi Goel, Matthew Green, Abhishek Jain, and Gabriel Kaptchuk. (Preprint Only). [eprint PDF]
  • How good is good enough for COVID19 apps? The influence of benefits, accuracy, and privacy on willingness to adopt.
      Gabriel Kaptchuk, Daniel G. Goldstein, Eszter Hargittai, Jake Hofman, and Elissa M. Redmiles (Preprint Only). [arXiv]
  • Giving State to the Stateless: Augmenting Trustworthy Computation with Ledgers.
     Gabriel Kaptchuk, Ian Miers, Matthew Green. NDSS 2019. [eprint PDF][Conference PDF][Code]
  • Fairness in an Unfair World: Fair Multiparty Computation from Public Bulletin Boards.
      Arka Rai Choudhuri, Matthew Green, Abhishek Jain, Gabriel Kaptchuk, Ian Miers. ACM CCS 2017. [eprint PDF] [Conference PDF]
  • Outsourcing Medical Dataset Analysis: A Possible Solution.
      Gabriel Kaptchuk, Matthew Green, Aviel D. Rubin. Financial Cryptography Conference 2017. [PDF]
  • Dancing on the Lip of the Volcano: Chosen Ciphertext Attacks on Apple iMessage.
      Christina Garman, Matthew Green, Gabriel Kaptchuk, Ian Miers, Michael Rushanan. USENIX Security 2016. [PDF]
  • A Practical Implementation of a Multi-Device Split Application for Protecting Online Poker.
      Gabriel Kaptchuk, Aviel D. Rubin. Annual Security Conference 2016. [PDF]

Recorded Talks

Press / Blogs