Mahimna Kelkar

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



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

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

[CV] [Scholar]

Publications and Preprints

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

  2. 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)
    [eprint]

  3. 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]

  4. 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]

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

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

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

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

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

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

  11. 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]

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

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

  14. Buying Time: Latency Racing vs. Bidding for Transaction Ordering
    Akaki Mamageishvili, Mahimna Kelkar, Jan Christoph Schlegel, Edward Felten
    AFT 2023
    [proc] [arxiv]

  15. 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]

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

  17. 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
    [proc] [eprint]

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

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

  20. 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)]

  21. 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)]

  22. 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