I am a Professor at the Khoury College of Computer Sciences at Northeastern. My research area is computer security and cryptography. My work currently focuses on secure computation protocols, zero-knowledge protocols and verifiable computation. My email is abhi at neu.edu.
My current work has focused on developing the Longfellow ZK protocol and deploying it in the Google Wallet. The zero-knowledge protocol is used to allow a user to prove any property about their digital identity to a website (a relying party) in a way that leaks no other information. My current interests are to formally verify this protocol’s security proof, as well as its implementation.
Students
My former PhD students include Mona Sergi (2013, Google), Chih-hao Shen (2014, Google), Ben Kreuter (2018, Google), Yash Kondi (2022, postdoc at Aarhus, researcher at Silence labs), Jack Doerner (2022, postdoc at Technion and Brown, assistant professor at U. of Virginia), and Eysa Lee (2023, postdoc at Brown, assistant professor at Barnard), Schuyler Rosefield, and LaKyah Tyner (2026, postdoc at Aarhus). Former post-doc and then research scientist Ran Cohen is now an assistant professor at IDC Herzliya.
Recent talks
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“The modern anonymous credential”, Simons Institute at Berkeley, August 2025.
I had so much fun giving this talk!
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15m talk on anonymous credentials at Real World Crypto (RWC2025)
So rushed, and so much to say.
Research
My research is supported by the National Science Foundation and several generous grants from companies.
Anonymous Credentials from ECDSA
Matteo Frigo, abhi shelat Communicatins in Cryptology, v3,n1, 2026 and eprint/2024/2010Guaranteed Output Delivery in O(sqrt(n)) rounds for Round Robin Sampling Protocols
Ran Cohen, Jack Doerner, Yash Kondi, abhi shelat J. of Cryptology, 2025Secure Multiparty Computation with Identifiable Abort from Vindicating Release
Ran Cohen, Jack Doerner, Yash Kondi, abhi shelat CRYPTO'2024Threshold ECDSA in Three Rounds
Jack Doerner, Yash Kondi, Eysa Lee, abhi shelat Oakland S&P'2024Threshold BBS+ Signatures for Distributed Anonymous Credential Issuance
Jack Doerner, Yash Kondi, Eysa Lee, abhi shelat, LakYah Tyner Oakland'23Improved Straighline Extraction in the ROM with Applications to Signature Aggregation
Yash Kondi, abhi shelat Asiacrypt'22Guaranteed Output Delivery in O(sqrt(n)) rounds for Round Robin Sampling Protocols
Ran Cohen, Jack Doerner, Yash Kondi, abhi shelat Eurocrypt'22Diogenes: Lightweight Scalable RSA Modulus Generation with a Dishonest Majority
Carmit Hazay, Megan Chen, Yuval Ishai, Yuriy Kashnikov, Daniele Micciancio, Tarik Riviere, abhi shelat, Ruihan Wang, Muthu Venkitasubramaniam Oakland'2021 and eprint 2020/374Multiparty Generation of an RSA Modulus
Megan Chen, Ran Cohen, Jack Doerner, Yashvanth Kondi, Eysa Lee, Schuyler Rosefield, abhi shelat CRYPTO'2020 and eprint 2020/370Going Beyond Dual Execution: MPC for Functions with Efficient Verification
Carmit Hazay and abhi shelat and Muthu Venkitasubramaniam PKC'2020 and eprint 2020/139Securely Sampling Biased Coins with Applications to Differential Privacy
Jeffrey Champion and abhi shelat and Jonathan Ullman CCS'2019 and eprint 2019/823Adaptively Secure MPC with Sublinear Communication Complexity
Ran Cohen and abhi shelat and Daniel Wichs CRYPTO'2019 and eprint 2018/1161Minimizing Trust in Hardware Wallets with Two Factor Signatures
Antonio Marcedone and Rafael Pass and abhi shelat Financial Crypto'2019Threshold ECDSA from ECDSA Assumptions The Multiparty Case
Jack Doerner and Yashvanth Kondi and Eysa Lee and abhi shelat Oakland S&P'2019A better method to analyze blockchain consistency
Lucianna Kiffer, Rajmohan Rajaraman, abhi shelat ACM CCS 2018Blind Certificate Authorities
Liang Wang, Gilad Asharov, Rafael Pass, Thomas Ristenpart, abhi shelat Oakland S&P'2019Secure Multi-party Threshold ECDSA from ECDSA Assumptions
Jack Doerner and Yashvanth Kondi and Eysa Lee and abhi shelat Oakland S&P'2018Multi-Key Searchable Encryption, Revisited
Ariel Hamlin and abhi shelat and Mor Weiss and Daniel Wichs PKC'2018Doubly-efficient zkSNARKs without trusted setup
Riad S. Wahby and Ioanna Tzialla and abhi shelat and Justin Thaler and Michael Walfish Oakland S&P'2018 and eprint/2017/1132Socially Optimal Mining Pools
Ben A. Fisch and Rafael Pass and abhi shelat WINE 2017 and arXivScaling ORAM for Secure Computation
Jack Doerner and abhi shelat CCS'2017 *Best paper award*, eprint/2017/827Full accounting for verifiable outsourcing
Riad S. Wahby and Ye Ji and Andrew J. Blumberg and abhi shelat and Justin Thaler and Michael Walfish and Thomas Wies CCS'2017 and eprint 2017/242Analysis of the Blockchain Protocol in Asynchronous Networks
Rafael Pass and Lior Seeman and abhi shelat Eurocrypt 2017 and eprint.iacr.org/2016/454Secure Stable Matching at Scale
Jack Doerner and Dave Evans and abhi shelat CCS'16Bounded KDM Security from iO and OWF
Antonio Marcedone and Rafael Pass and abhi shelat SCN'16The Cut-and-Choose Game and its Application to Cryptographic Protocols
Ruiyu Zhu, Yan Huang, Jonathan Katz, abhi shelat USENIX Security 2016Verifiable ASICs
Riad S. Wahby and Max Howald and Siddharth Garg and abhi shelat and Michael Walfish Oakland S&P 2016 *Best student paper award*How to Use SNARKs in Universally Composable Protocols
Ahmed Kosba, Zhichao Zhao,rew Miller, Hubert Chan, Charalampos Papamanthou, Rafael Pass, abhi shelat and Elaine Shi eprint/2015/1093Lower Bounds on Assumptions behind Indistinguishability Obfuscation
Mohammad Mahmoody, Ameer Mohammed, Soheil Nematihaji, Rafael Pass and abhi shelat TCC 2016Impossibility of VBB Obfuscation with Ideal Constant-Degree Graded Encodings
Rafael Pass and abhi shelat TCC 2016Secure Computation from Millionaire
abhi shelat and Muthu Venkitasubramaniam Asiacrypt 2015Micropayments for Peer-to-peer currencies
Rafael Pass and abhi shelat ACM Conf on Computer Security (CCS) 2015An Overview of ANONIZE: A Large scale anonymous survey system
S. Hohenberger, S. Myers, R. Pass, and a. shelat IEEE Security & Privacy Journal, Vol 13, No 2, Mar 2015.Oblivious RAM for Secure Computation
Xiao Wang, Hubert Chen, Yan Huang, abhi shelat, Elaine Shi ACM Conf on Computer Security (CCS) 2014ANONIZE: A Large-Scale Anonymous Survey System
Susan Hohenberger, Steven Myers, Rafael Pass, abhi shelat IEEE Security & Privacy (Oakland) 2014GPU and CPU Parallelization of Secure Two-Party Computation
Nathaniel Husted, Steven Myers, and abhi shelat Annual Computer Security Applications Conf (ACSAC) 2013Fast Two-Party Secure Computation with Minimal Assumptions
Chih-hao Shen, abhi shelat ACM Conf on Computer Security (CCS) 2013Lessons learned with PCF Scaling Secure Computation
Ben Kreuter, abhi shelat Workshop on language support for Privacy Enhancing Technologies (PETSHOP) 2013PCF: A Portable Circuit Format For Scalable Two-Party Secure Computation
Benjamin Kreuter, a.shelat, Benjamin Mood, Kevin Butler USENIX Security, 2013Algorithms for Compressed Inputs
Nathan Brunelle, Gabe Robins, abhi shelat Data Compression Conference, 2013 (poster)Blackbox Construction of A More Than Non-Malleable CCA1 Encryption Scheme from Plaintext
Steve Myers, Mona Sergi, abhi shelat J. of Computer Security, Vol 21, No 5, pp 721–748Black-Box Proof of Knowledge of Plaintext and Multiparty Computation with Low Communication Overhead
Steve Myers, Mona Sergi, abhi shelat Theory of Cryptography Conference (TCC) 2013Billion-Gate Secure Computation with Malicious Adversaries
Ben Kreuter, Chih-hao Shen, abhi shelat USENIX Security 2012Matching by propensity score in cohort studies with three treatment groups
J. A. Rassen, a. shelat, J. Myers, R.J. Glynn, and S. Schneeweiss Epidemiology, in press 2012One-to-many propensity score matching in cohort studies,
J. A. Rassen, a. shelat, J. Myers, R. Glynn, K. Rothman, S. Schneeweiss J. of Pharmacoepidemiology and Drug Safety, v21.S2, 12 pages, May 2012Computing on Authenticated Data
J.Ahn, D.Boneh, J.Camenisch, S.Hohenberger, a.shelat, and B.Waters Theory of Cryptography Conference 2012Efficient Secure Computation with Garbled Circuits
Y. Huang, C.~Shen, D.~Evans, J.~Katz, and a.~shelat Information systems security 2011Blackbox Construction of A More Than Non-Malleable CCA1 Encryption Scheme from Plaintext Awareness
Steve Myers, Mona Sergi, abhi shelat Secure Computer Networks (SCN) 2011Two-output Secure Computation With Malicious Adversaries
Chih-hao Shen and a. shelat Eurocrypt 2011A Sub-0.5V Lattice-Based Public-Key Encryption Scheme for RFID Platforms in 130nm CMOS
Yu Yao, Sudhanshu Khanna, Ben Calhoun, Dave Evans, John Lach, and a. shelat RFIDSEC’11 AsiaRenegotiation-safe Protocols
Rafael Pass and a. shelat Innovations in Computer Science ’11 (ICS’11)Optimistic Concurrent Zero Knowledge
Alon Rosen and a. shelat Asiacrypt ’10Additive Combinatorics and Discrete Logarithm Based Range Protocols
R. Chaabouni, H. Lipmaa, a.shelat Australasian conf Inf Security & Privacy (ACISP’10) andBit Encryption is Complete
Steven Myers and abhi shelat. FOCS 2009. Proceedings versionCollusion-Free Multiparty Computation in the Mediated Model
J. Alwen, J. Katz, Y. Lindell, G. Persiano, a. shelat, and I. Visconti. CRYPTO 2009. Santa Barbara, CA.Purely Rational Secret Sharing
Silvio Micalli and abhi shelat. Theory of Cryptography Conference (TCC) 2009.Efficient Protocols for Set Membership and Range Proofs
Jan Camenisch, Rafik Chaabouni, and abhi shelat ASIACRYPT 2008Collusion-Free Protocols in the Mediated Model
Joel Alwen, abhi shelat, and Ivan Visconti CRYPTO 2008Bounded CCA2-Secure Encryption
Ronald Cramer, Goichiro Hanaoka, Dennis Hofheinz, Hideki Imai, Eike Kiltz, Rafael Pass, abhi shelat, and Vinod Vaikuntanathan. ASIACRYPT’07, December 2007, Kuching, Malaysia.Relations Among Notions of Non-Malleability for Encryption
Rafael Pass, abhi shelat, and Vinod Vaikuntanathan. ASIACRYPT’07, December 2007, Kuching, Malaysia.Cryptography from Sunspots: How to use an Imperfect Reference String
Ran Canetti, Rafael Pass, and abhi shelat Foundations of Computer Science (FOCS’07), Providence, Rhode Island, October 2007.Efficient Fork-Linearizable Access to Untrusted Shared Memory
Christian Cachin, abhi shelat, and Alex Shraer Principles of Distributed Computing (PODC’07), Portland, Oregan, Aug 2007.Simulatable Adaptive Oblivious Transfer
Jan Camenisch, Gregory Neven, and abhi shelat EUROCRYPT 2007, Barcelona, Spain, May 2007. p.573-590.Securely Obfuscating Re-encryption
Susan Hohenberger, Guy Rothblum, abhi shelat, and Vinod Vaikuntanathan Theory of Cryptography Conference (TCC’07), Amsterdam, The Netherlands, Feb 2007, p. 233-252.Construction of a Non-malleable Encryption Scheme from Any Semantically-Secure One
Rafael Pass, abhi shelat, and Vinod Vaikuntanathan CRYPTO’06, Santa Barbara, CA, Aug 2006, p.271-289.Unconditional Characterizations of Non-Interactive Zero-Knowledge
Rafael pass and abhi shelat CRYPTO’05, Santa Barbara, CA, Aug 2005, p.118-134.The Smallest Grammar Problem
Moses Charikar, Eric Lehman, Ding Liu, Rina Panigrahy, Manoj Prabhakaran, Amit Sahai, abhi shelat IEEE Transactions on Information Theory, Vol. 51, Issue 7, Jul 2005, p2554-2576.Collusion-free Protocols
Matt Lepinski and Silvio Micali and abhi shelat Symposium on the Theory of Computation (STOC’05), Baltimore, MD, May 2005, p.543-552.Fair Zero Knowledge
Matt Lepinski and Silvio Micali and abhi shelat Theory of Cryptography (TCC’05), Cambridge, MA, Feb 2005, p.245-263.Completely Fair SFE and Coalition-Safe Cheap Talk
Matt Lepinski and Silvio Micali and Chris Peikert and abhi shelat Principles of Distributed Computing (PODC’04), St. John’s Newfoundland, Jul 2004, p.1-10.Searching for Stable Mechanisms : Automated Design for Imperfect Players
Andrew Blumberg and abhi shelat AAAI 2004Remembrance of Data Passed: A Study of Disk Sanitization Practices
Simson Garfinkel and abhi shelat IEEE Security and Privacy, January/February 2003Lower Bounds for Collusion-Secure Fingerprinting
Chris Peikert, abhi shelat, and Adam Smith SODA 2003Approximating the Smallest Grammar: Kolmogorov Complexity in Natural Models
Moses Charikar, Eric Lehman, Ding Liu, Rina Panigrahy, Manoj Prabhakaran, April Rasala, Amit Sahai, abhi shelat STOC 2002Approximation Algorithms for Grammar-Based Compression
Eric Lehman and abhi shelat SODA 2002