Mahimna Kelkar
mahimna [at] cs {dot} cornell (dot) edu
mahimna [at] purdue (dot) edu
I am a CS postdoc at Columbia University affiliated with
The Columbia-Ethereum Research Center.
I recently graduated with a PhD from Cornell where I was advised by
Ari Juels
.
My research focuses broadly on applied cryptography, security, and blockchains.
I am also a research scientist at
Offchain Labs
.
In Fall 2026, I will start as an Assistant Professor of Computer Science at
Purdue
.
I plan to hire multiple PhD students in the 2025-26 application cycle. If you're interested, drop me an email and
apply
by Dec 1.
[CV]
[Scholar]
[Short Research Statement]
All Publications
PROF: Protected Order Flow in a Profit-Seeking World
Kushal Babel, Nerla Jean-Louis, Yan Ji, Ujval Misra,
Mahimna Kelkar
, Kosala Yapa Mudiyanselage, Andrew Miller, Ari Juels
IEEE EuroS&P 2026
Breaking Omertà: On Threshold Cryptography, Smart Collusion, and Whistleblowing
Mahimna Kelkar*
, Aadityan Ganesh*, Aditi Partap, Joseph Bonneau, S. Matthew Weinberg (*equal contribution)
ACM CCS 2025
Liquefaction: Privately Liquefying Blockchain Assets
James Austgen, Andrés Fábrega,
Mahimna Kelkar
, Dani Vilardell, Sarah Allen, Kushal Babel, Jay Yu, Ari Juels
IEEE S&P (Oakland) 2025
Voting-Bloc Entropy: A New Metric for DAO Decentralization
Andrés Fábrega, Amy Zhao, Jay Yu, James Austgen, Sarah Allen, Kushal Babel,
Mahimna Kelkar
, Ari Juels
USENIX Security 2025
Secure Sorting and Selection via Function Secret Sharing
(alphabetical ordering)
Amit Agarwal, Elette Boyle, Nishanth Chandran, Niv Gilboa, Divya Gupta, Yuval Ishai,
Mahimna Kelkar
, Yiping Ma
ACM CCS 2024
Atomic and Fair Data Exchange via Blockchain
Ertem Nusret Tas, István András Seres, Yinuo Zhang, Márk Melczer,
Mahimna Kelkar
, Joseph Bonneau, Valeria Nikolaenko
ACM CCS 2024
Distinguished Paper Award
Complete Knowledge: Preventing Encumbrance of Cryptographic Secrets
Mahimna Kelkar*
, Kushal Babel*, Philip Daian*, James Austgen, Vitalik Buterin, Ari Juels (*equal contribution)
ACM CCS 2024
Computationally Secure Aggregation and Private Information Retrieval in the Shuffle Model
(alphabetical ordering)
Adrià Gascón, Yuval Ishai,
Mahimna Kelkar
, Baiyu Li, Yiping Ma, Mariana Raykova
ACM CCS 2024
Interactive Authentication
Deepak Maram,
Mahimna Kelkar
, Ittay Eyal
ACM CCS 2024
BoLD: Fast and Cheap Dispute Resolution
(alphabetical ordering)
Mario M. Alvarez et al.
AFT 2024
Compressing Unit-Vector Correlations via Sparse Pseudorandom Generators
(alphabetical ordering)
Amit Agarwal, Elette Boyle, Niv Gilboa, Yuval Ishai,
Mahimna Kelkar
, Yiping Ma
CRYPTO 2024
Information-Theoretic Single-Server PIR in the Shuffle Model
(alphabetical ordering)
Yuval Ishai,
Mahimna Kelkar
, Daniel Lee, Yiping Ma
ITC 2024
GoAT: File Geolocation via Anchor Timestamping
Deepak Maram,
Mahimna Kelkar
, Iddo Bentov, Ari Juels
FC 2024
Truncator: Time-space Tradeoff of Cryptographic Primitives
(alphabetical ordering)
Foteini Baldimtsi, Konstantinos Chalkias, Panagiotis Chatzigiannis,
Mahimna Kelkar
FC 2024
Lanturn: Measuring Economic Security of Smart Contracts Through Adaptive Learning
Kushal Babel*, Mojan Javaheripi*, Yan Ji,
Mahimna Kelkar
, Farinaz Koushanfar, Ari Juels
ACM CCS 2023
Themis: Fast, Strong Order-Fairness in Byzantine Consensus
Mahimna Kelkar
, Soubhik Deb, Sishan Long, Ari Juels, Sreeram Kannan
ACM CCS 2023
Prototyped by Chainlink
Zef: Low-latency, Scalable, Private Payments
Mathieu Baudet, Alberto Sonnino,
Mahimna Kelkar
, George Danezis
WPES 2023
Commercialized by Linera
Buying Time: Latency Racing vs. Bidding for Transaction Ordering
Akaki Mamageishvili,
Mahimna Kelkar
, Jan Christoph Schlegel, Edward Felten
AFT 2023
STROBE: Streaming Threshold Random Beacons
(alphabetical ordering)
Donald Beaver, Konstantinos Chalkias,
Mahimna Kelkar
, Lefteris Kokoris Kogias, Kevin Lewi, Ladi de Naurois, Valeria Nikolaenko, Arnab Roy, Alberto Sonnino
AFT 2023
One-Message Secure Reductions: On the Cost of Converting Correlations
(alphabetical ordering)
Yuval Ishai,
Mahimna Kelkar
, Varun Narayanan, Liav Zafar
CRYPTO 2023
Clockwork Finance: Automated Analysis of Economic Security in Smart Contracts
Kushal Babel*, Philip Daian*,
Mahimna Kelkar*
, Ari Juels (*equal contribution)
IEEE S&P (Oakland) 2023
SCRF Research Impact Award
Best 2023 DeFi Paper (awarded by the DeFi Workshop at CCS 2024)
Order-Fair Consensus in the Permissionless Setting
Mahimna Kelkar
, Soubhik Deb, Sreeram Kannan
Short version in APKC 2022
Best Paper Award
Secure Poisson Regression
Mahimna Kelkar
, Phi Hung Le, Mariana Raykova, Karn Seth
USENIX Security 2022
MPC-Friendly Symmetric Cryptography from Alternating Moduli: Candidates, Protocols, and Applications
(alphabetical ordering)
Itai Dinur, Steven Goldfeder, Tzipora Halevi, Yuval Ishai,
Mahimna Kelkar
, Vivek Sharma, Greg Zaverucha
CRYPTO 2021
Order-Fairness for Byzantine Consensus
Mahimna Kelkar
, Fan Zhang, Steven Goldfeder, Ari Juels
CRYPTO 2020
Flexible Signatures: Towards Making Authentication Suitable for Real-Time Environments
Duc V. Le,
Mahimna Kelkar
, Aniket Kate
ESORICS 2019
Other Manuscripts
The Sting Framework: Proving the Existence of Superclass Adversaries
Mahimna Kelkar
, Yunqi Li, Nerla Jean-Louis, Carolina Ortega Pérez, Kushal Babel, Andrew Miller, Ari Juels
eprint 2024
DAO Decentralization: Voting-Bloc Entropy, Bribery, and Dark DAOs
James Austgen*, Andrés Fábrega*, Sarah Allen, Kushal Babel,
Mahimna Kelkar
, Ari Juels
2023.
Superseded by Voting-Bloc Entropy [FZY+25] and Liquefaction [AFK+25]
Dissertation
Rethinking Security for Emerging Decentralized Systems
Mahimna Kelkar
2025.
Cornell University PhD Dissertation
Selected Talks
Omertà Collusion
IC3, a16z crypto, MEV@SBC'25, Columbia, Yale, CCS'25, Offchain Labs, Duke, Amazon, Princeton, University of Sydney.
Complete Knowledge
CMU, Stanford, UPenn, a16z crypto, IC3 Bootcamp, SBC'24, NYC Crypto Day, CCS'24, Boston University, MIT
PIR in the Shuffle Model
ITC'24
Timeboost
[M
K
SF23]
AFT'23
Clockwork Finance
Technion, SEC Finhub, DeFi@CCS'24
Zef
WPES'23
Secure Poisson Regression
Google, PPML'21, USENIX Security'22
MPC-friendly Symmetric Cryptography
CRYPTO'21, TCC'21
Order-Fair Consensus
(based on [
K
ZGJ20], [
K
DK22], and [
K
DLJK23])
Industry:
Google, Facebook, Visa, a16z, Algorand, Chainlink, Flashbots, Offchain Labs, Protocol Labs, SEC Finhub
Universities:
Cornell, Duke, Purdue, Technion, UIUC
Conferences and Workshops:
CRYPTO'20, TCC'21, TPBC'21, Consensus Day '21, APKC'22, SBC'22, CCS'23
Internships and Visits
(Summer 2023)
a16z crypto research
-
Hosted by Joseph Bonneau, Valeria Nikolaenko, and Tim Roughgarden
(Spring 2022)
Technion
-
Hosted by Yuval Ishai
(Summer 2021)
Facebook Research
-
Novi Blockchain Cryptography Team
(Summer 2020)
Google Research
-
Private Computing Team hosted by Karn Seth and Mariana Raykova
(Summer 2018)
Sandia National Laboratories
(Summer 2017)
Amazon
-
Software Engineering Intern at AWS Lambda
Service
Program committees
: FC {2024, 2025, 2026}, DeFi Workshop {2023, 2024}, CCS 2026
External reviewer
: FC 2020, CRYPTO {2020, 2021, 2024, 2026}, Eurocrypt 2022, DISC 2022, CCS 2022, USENIX Security 2020, DES Journal, AFT 2023, PODC {2024,2026}, ITCS 2025