This was my website during grad school! It is no longer actively updated. My current website can be found here.

About Me

I am a final-year PhD student in the Computer Science department at Cornell University, advised by Tom Ristenpart. I'm located at the Cornell Tech campus in NYC.
I will be joining the University of Michigan as an Assistant Professor in Fall 2021!


My research is in security, cryptography, and systems. I study ways to use encryption to build systems that are both secure and functional. I am focusing on encrypted database systems and content moderation for end-to-end encrypted messaging.

I'm also broadly interested in making systems security failures less harmful, using encryption and other tools.
I like thinking about post-quantum cryptography, new primitives, and constructing protocols that solve interesting problems.

My non-technical interests include censorship, privacy, legal and ethical issues related to information security, and the intersection of technology and society.

My research is supported in part by a 2017 NSF Graduate Research Fellowship.


In Spring 2018, I visited Royal Holloway, University of London, located in scenic Egham, UK.
While I was there, I worked with several lovely people including Marie-Sarah Lacharité, Brice Minaud, Kenny Paterson, and Joanne Woodage.


Pancake: Frequency Smoothing for Encrypted Data Stores USENIX Security 2020 (Distinguished Paper Award)
Paul Grubbs, Anurag Khandelwal, Marie-Sarah Lacharité, Lloyd Brown, Lucy Li, Rachit Agrawal, and Thomas Ristenpart
The first three authors contributed equally to this work.

Asymmetric Message Franking: Content Moderation for Metadata-Private End-to-End Encryption CRYPTO 2019
Nirvan Tyagi, Paul Grubbs, Julia Len, Ian Miers, and Thomas Ristenpart

Learning to Reconstruct: Statistical Learning Theory and Encrypted Database Attacks IEEE Symposium on Security and Privacy 2019
Paul Grubbs, Marie-Sarah Lacharité, Brice Minaud, and Kenny Paterson
Blogs about this work: Matt Green, Bruce Schneier

Pump Up The Volume: Practical Database Reconstruction from Volume Leakage on Range Queries CCS 2018
Paul Grubbs, Marie-Sarah Lacharité, Brice Minaud, and Kenny Paterson

Fast Message Franking: From Invisible Salamanders to Encryptment CRYPTO 2018
Yevgeniy Dodis, Paul Grubbs, Thomas Ristenpart, and Joanne Woodage
Here's a video of Joanne's RWC 2019 talk on this work.

The Tao of Inference in Privacy-Protected Databases PVLDB 2018
Vincent Bindschaedler, Paul Grubbs, David Cash, Thomas Ristenpart, and Vitaly Shmatikov

Message Franking via Committing Authenticated Encryption CRYPTO 2017
Paul Grubbs, Jiahui Lu, and Thomas Ristenpart
Zoom's current end-to-end encryption design (v2) uses the CtE1 scheme we introduced in this work.

Why Your Encrypted Database Is Not Secure HotOS 2017 (slides)
Paul Grubbs, Thomas Ristenpart, and Vitaly Shmatikov

Leakage-Abuse Attacks against Order-Revealing Encryption IEEE Symposium on Security and Privacy 2017
Paul Grubbs, Kevin Sekniqi, Vincent Bindschaedler, Muhammad Naveed, and Thomas Ristenpart

Side-Channel Attacks on Shared Search Indexes IEEE Symposium on Security and Privacy 2017
Liang Wang, Paul Grubbs, Jiahui Lu, Vincent Bindschaedler, David Cash, and Thomas Ristenpart

Modifying an Enciphering Scheme After Deployment Eurocrypt 2017
Paul Grubbs, Thomas Ristenpart, and Yuval Yarom

Breaking web applications built on top of encrypted data CCS 2016
Paul Grubbs, Richard McPherson, Muhammad Naveed, Thomas Ristenpart, and Vitaly Shmatikov
FAQ about this work

Leakage-Abuse Attacks Against Searchable Encryption CCS 2015
David Cash, Paul Grubbs, Jason Perry, and Thomas Ristenpart

GPU and CPU parallelization of honest-but-curious secure two-party computation ACSAC 2013
Nathaniel Husted, Steve Myers, abhi shelat, and Paul Grubbs


Hunting Invisible Salamanders: Cryptographic (in)Security with Attacker-Controlled Keys BlackHat, August 2020
   An article and video about my talk appeared on Dark Reading.
Learning to Reconstruct: Statistical Learning Theory and Encrypted Database Attacks ICERM Workshop on Encrypted Search, June 2019
Message Franking: Invisible Salamanders, Encryptment, and AMFs
   NYC Crypto Day (May 2019), Workshop on Secure Messaging (May 2019), Stanford Security Seminar (May 2019)
Why Your Encrypted Database is Not Secure Second ESSA workshop, 2018
Breaking web applications built on top of encrypted data Real World Cryptography 2017
New Inference Attacks on Order-Preserving Encryption DC Crypto Day, May 2016
On Deploying Property-Preserving Encryption Real World Cryptography 2016
Searchable the REAL world ESSA Workshop, 2015


Teaching Assistant for CS 5830: Cryptography, Spring 2017
Teaching Assistant for CS 5435: Security and Privacy Concepts in the Wild, Fall 2019


I was a program committee member for SAC 2019.


I did my undergrad at Indiana University, where I majored in Math and Computer Science.
After graduating, I worked for two and a half years at Skyhigh Networks as a cryptography engineer. I left in August of 2015 to start grad school at Cornell.


You can tweet at me @pag_crypto or find me on LinkedIn.
My email address is pag[220+5] AT cornell DOT edu. Compute the sum in the braces and append that to "pag" to get the local part of the email address.
Me recently
A recent picture of me