Bio

I'm a Research Professor in BU computer science focusing on privacy. I also am a Civic Tech Fellow at the Faculty of Computing and Data Sciences at BU and have an affiliation with BU's 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.

MPC FAQ

I have compiled an FAQ about secure multiparty computation (MPC) aimed at non-experts. The FAQ can be found here. If you notice some way in which it can be improved, please send me an email!

Teaching

Publications

(Authors alphabetical by default. Publications ordered by contribution marked with *)
  • Efficient Proofs of Software Exploitability for Real-world Processors
      Matthew Green, Mathias Hall-Andersen, Eric Hennenfent, Gabriel Kaptchuk, Benjamin Perez, and Gijs Van Laer. PoPETS 2023. [eprint PDF]
  • Stacking Sigmas: A Framework to Compose Σ-Protocols for Disjunctions.
      Aarushi Goel, Matthew Green, Mathias Hall-Andersen, and Gabriel Kaptchuk. EUROCRYPT 2022. [eprint PDF]
  • Efficient Set Membership using MPC-in-the-Head.
      Aarushi Goel, Matthew Green, Mathias Hall-Andersen, and Gabriel Kaptchuk. PoPETS 2022. [eprint PDF] [Conference 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. ACM Digital Threats: Research and Practice Special Issue on COVID-19. [Journal Version] [arXiv]
  • Fluid MPC: Secure Multiparty Computation with Dynamic Participants.
      Arka Rai Choudhuri, Aarushi Goel, Matthew Green, Abhishek Jain, and Gabriel Kaptchuk. CRYPTO 2021 [eprint PDF]
  • Meteor: Cryptographically Secure Steganography for Realistic Distributions.*
     Gabriel Kaptchuk, Tushar Jois, Matthew Green, and Aviel D. Rubin. ACM CCS 2021. [PDF] [eprint PDF] [Website & Demo with Code]
  • "I need a better description": An Investigation Into User Expectations For Differential Privacy (Best Paper Runner-up)
     Rachel Cummings, Gabriel Kaptchuk, and Elissa Redmiles. ACM CCS 2021. [PDF] [arXiv] [TPDP Poster]
  • Abuse Resistant Law Enforcement Access Systems
     Matthew Green, Gabriel Kaptchuk, and Gijs Van Laer. EUROCRYPT 2021. [eprint PDF]
  • Order-C Secure Multiparty Computation for Highly Repetitive Circuits
     Gabrielle Beck, Aarushi Goel, Abhishek Jain, and Gabriel Kaptchuk. EUROCRYPT 2021 [eprint PDF]
  • Improving Signal's Sealed Sender.*
     Ian Martiny, Gabriel Kaptchuk, Adam Aviv, Daniel Roche, and Eric Wustrow. NDSS 2021. [PDF] [Code]
  • 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]

Publicly Recorded Talks

  • Efficient Set Membership using MPC-in-the-Head. (PETs 22) [Video] [PDF Slides]
  • Commit Acts of Steganography—Before it's too late. (RWC 2022) [Video] [PDF Slides]
  • Weaving Social Accountability Into Cryptographic Protocols (Charles River Area Crypto Day 2022) [PPTX Slides]
  • Meteor: Cryptographically Secure Steganography for Realistic Distributions. (ACM CCS 2021) [Video] [PDF Slides]
  • "I need a better description": An Investigation Into User Expectations For Differential Privacy. (ACM CCS 2021) [Video] [PDF Slides]
  • Abuse Resistant Law Enforcement Access Systems. (EUROCRYPT 2021) [Video] [PDF Slides]
  • Order-C Secure Multiparty Computation for Highly Restitive Circuits. (EUROCRYPT 2021) [Video] [PDF Slides]
  • Giving State to the Stateless: Augmenting Trustworthy Computation with Ledgers (NDSS 2019) [Video] [PDF Slides]
  • The Hill We Must Die On: Cryptographers and Congress (RWC 2019) [Video] [PDF Slides]
  • Presentation for Fairness in an Unfair World (CCS 2017) [Video] [PPTX Slides]

Press / Blogs