Mahimna Kelkar

mahimna [at] cs {dot} cornell (dot) edu



I am a final year PhD student in Computer Science at Cornell University advised by Ari Juels.
My research interests are in applied cryptography and security with a special emphasis on blockchains.

I completed my undergrad at Purdue, where I majored in Computer Science, Mathematics, and Statistics.

I am on the academic job market for the 2024-25 cycle!

[CV] [Scholar]

Publications and Preprints

  1. 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
    2024
    [eprint]

  2. 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
    2024
    [arxiv]

  3. DAO Decentralization: Voting-Bloc Entropy, Bribery, and Dark DAOs
    James Austgen*, Andrés Fábrega*, Sarah Allen, Kushal Babel, Mahimna Kelkar, Ari Juels
    2023
    [arxiv]

  4. 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 (to appear)

  5. 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 (to appear)
    Distinguished Paper Award
    [eprint]

  6. Complete Knowledge: Preventing Encumbrance of Cryptographic Secrets
    Mahimna Kelkar*, Kushal Babel*, Philip Daian*, James Austgen, Vitalik Buterin, Ari Juels (*equal contribution)
    ACM CCS 2024 (to appear)
    [eprint]

  7. 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 (to appear)
    [eprint]

  8. Interactive Authentication
    Deepak Maram, Mahimna Kelkar, Ittay Eyal
    ACM CCS 2024 (to appear)
    [eprint]

  9. BoLD: Fast and Cheap Dispute Resolution
    (alphabetical ordering) Mario M. Alvarez et al.
    AFT 2024 (to appear)
    [proc] [arxiv]

  10. Compressing Unit-Vector Correlations via Sparse Pseudorandom Generators
    (alphabetical ordering) Amit Agarwal, Elette Boyle, Niv Gilboa, Yuval Ishai, Mahimna Kelkar, Yiping Ma
    CRYPTO 2024
    [proc]

  11. Information-Theoretic Single-Server PIR in the Shuffle Model
    (alphabetical ordering) Yuval Ishai, Mahimna Kelkar, Daniel Lee, Yiping Ma
    ITC 2024
    [proc] [eprint]

  12. GoAT: File Geolocation via Anchor Timestamping
    Deepak Maram, Mahimna Kelkar, Iddo Bentov, Ari Juels
    FC 2024
    [proc] [eprint]

  13. Truncator: Time-space Tradeoff of Cryptographic Primitives
    (alphabetical ordering) Foteini Baldimtsi, Konstantinos Chalkias, Panagiotis Chatzigiannis, Mahimna Kelkar
    FC 2024
    [proc] [eprint]

  14. 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
    [proc] [eprint]

  15. Themis: Fast, Strong Order-Fairness in Byzantine Consensus
    Mahimna Kelkar, Soubhik Deb, Sishan Long, Ari Juels, Sreeram Kannan
    ACM CCS 2023
    [proc] [eprint]

  16. Zef: Low-latency, Scalable, Private Payments
    Mathieu Baudet, Alberto Sonnino, Mahimna Kelkar, George Danezis
    WPES 2023
    Commercialized by Linera
    [proc] [eprint]

  17. Buying Time: Latency Racing vs. Bidding for Transaction Ordering
    Akaki Mamageishvili, Mahimna Kelkar, Jan Christoph Schlegel, Edward Felten
    AFT 2023
    [proc] [arxiv]
    [AFT Talk (25 min)]

  18. 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
    [proc] [eprint]

  19. One-Message Secure Reductions: On the Cost of Converting Correlations
    (alphabetical ordering) Yuval Ishai, Mahimna Kelkar, Varun Narayanan, Liav Zafar
    CRYPTO 2023
    [proc] [eprint]

  20. 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)
    [proc] [eprint]

  21. Order-Fair Consensus in the Permissionless Setting
    Mahimna Kelkar, Soubhik Deb, Sreeram Kannan
    Short version in APKC 2022
    Best Paper Award
    [proc] [eprint]

  22. Secure Poisson Regression
    Mahimna Kelkar, Phi Hung Le, Mariana Raykova, Karn Seth
    USENIX Security 2022
    [proc] [eprint]
    [Usenix Talk (15 min)]

  23. 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
    [proc] [eprint]
    [CRYPTO Talk (25 min)]

  24. Order-Fairness for Byzantine Consensus
    Mahimna Kelkar, Fan Zhang, Steven Goldfeder, Ari Juels
    CRYPTO 2020
    [proc] [eprint]
    [IC3 Talk (15 min)] [CRYPTO Talk (25 min)] [Chainlink Talk (45 min)]

  25. Flexible Signatures: Towards Making Authentication Suitable for Real-Time Environments
    Duc V. Le, Mahimna Kelkar, Aniket Kate
    ESORICS 2019
    [proc] [eprint] [poster]

Teaching

Internships and Visits

Academic Service