I am a third-year computer science PhD student at Columbia University, where I am a member of the Theory Group and the Crypto Lab. I am fortunate to be co-advised by Tal Malkin and Mihalis Yannakakis. I'm interested in practically motivated theoretical problems, especially in the areas of cryptography, privacy, and complexity.
This spring (2023), I am a visiting student at the Simons Institute, participating in the Meta-Complexity program.
In summer and fall 2022, I was a research intern at the a16z crypto research group, led by Tim Roughgarden. There, I've (co)-written blog posts on Leader Election from Randomness Beacons and Other Strategies (with Valeria Nikolaenko and Joseph Bonneau) and TCC '22 Field Notes.
I co-organize the Columbia Theory Student Seminar; please reach out if you'd like to give a talk.
Limits on Revocable Proof Systems, with Applications to Stateless Blockchains. M. Christ, J. Bonneau, Financial Cryptography 2023. [ePrint]
The Smoothed Complexity of Policy Iteration for Markov Decision Processes. M. Christ, M. Yannakakis, STOC 2023. [arxiv]
Differential Privacy and Swapping: Examining De-Identification's Impact on Minority Representation and Privacy Preservation in the U.S. Census. M. Christ, S. Radway, S.M. Bellovin, IEEE S&P 2022. [pdf, IEEE, Columbia Engineering article]
Poly Onions: Achieving Anonymity in the Presence of Churn. M. Ando, M. Christ, A. Lysyanskaya, T. Malkin, TCC 2022. [ePrint, TCC talk]
Email: mchrist at cs dot columbia dot edu