Nikhil Vanjani

Senior Researcher

Babylon Labs

About

I am a Senior Researcher at Babylon Labs, where my work lies at the intersection of cryptography and blockchains, with a particular focus on garbled circuits, digital signatures, and zk-SNARKs. I aim to design expressive, efficient, and privacy-preserving systems that bridge the gap between provable security and real-world deployment.

I recently finished my PhD in December 2025 at Carnegie Mellon University, where I was fortunate to have Elaine Shi as my advisor. Previously, I received MS in Information Security in 2021 from Carnegie Mellon University where I was also advised by Elaine. Even before, I received B.Tech. in Computer Science and Engineering in 2018 from IIT Kanpur. I have done research internships in industry at NTT Research, 0xPARC Foundation, and Algorand. Even before, I worked on distributed systems as a software developer at Cohesity.

You can find my CV here.

Recent News

August 2026: Our work on the first large-universe ABE constructions from LWE got accepted to CCS'26
January 2026: Joined Babylon Labs as a Senior Researcher!
September 2025: Our work on broadening functionality and improving efficiency of Functional Adaptor Signatures got accepted to S&P (Oakland)‘26
August 2025: Our work on showing fully adaptive security of the classic Lewko-Waters MA-ABE got accepted to Asiacrypt'25
June 2025: Attended Cryptography 10 Years Later program at Simons Institute
June 2025: Research Internship at NTT Research
March 2025: Research Internship at 0xPARC Foundation
August 2024: Our work on enabling functional fair exchange via Functional Adaptor Signatures got accepted to CCS'24
June 2024: Research Internship at NTT Research

Publications

*: denotes first author

[6] Large-Universe (Multi-Authority) ABE from LWE.
Pratish Datta, Yannis Rouselakis, Junichi Tomida, Nikhil Vanjani.
(To Appear) In ACM SIGSAC Conference on Computer and Communications Security (CCS), 2026.

[5] New Constructions of Functional Adaptor Signatures: Broader Functions and Improved Efficiency.
Nikhil Vanjani*, Garrett Greiner*, Sri Aravinda Krishnan Thyagarajan, Pratik Soni.
In IEEE Symposium on Security and Privacy, 2026.

[4] Fully Adaptive Decentralized MA-ABE: Simplified, Optimized, ASP Supported.
Pratish Datta, Junichi Tomida, Nikhil Vanjani.
In Asiacrypt, 2025.

[3] Functional Adaptor Signatures: Beyond All-or-Nothing Blockchain-based Payments.
Nikhil Vanjani*, Pratik Soni, Sri Aravinda Krishnan Thyagarajan.
In ACM SIGSAC Conference on Computer and Communications Security (CCS), 2024.
Contributed talk at Theory and Practice of Multi-Party Computation (TPMPC) Workshop, 2025.

[2] Non-Interactive Anonymous Router with Quasi-Linear Router Computation.
Rex Fernando, Elaine Shi, Pratik Soni, Nikhil Vanjani, Brent Waters.
In Theory of Cryptography Conference (TCC), 2023.

[1] Multi-Client Inner Product Encryption: Function-Hiding Instantiations Without Random Oracles.
Elaine Shi, Nikhil Vanjani (randomized author order).
In International Conference on Practice and Theory of Public-Key Cryptography (PKC), 2023.

Manuscripts

[2] Non-Interactive Translation of Winternitz Signatures to Lamport Signatures via Secret Sharing.
Mikhail Sergeevitch, Konrad Staniec, David Tse, Nikhil Vanjani, Robin Linus Woll.
In Submission, 2026.

[1] Unbounded Large-Universe Decentralized MA-ABE from Static Assumptions.
Pratish Datta, Junichi Tomida, Nikhil Vanjani.
In Submission, 2026.

Theses

Functional Encryption and its Applications to Decentralized Systems.
Nikhil Vanjani.
PhD thesis.

Multi-Input Inner Product Encryption: Function-Hiding Instantiations without Random Oracles.
Nikhil Vanjani.
Masters thesis.

Software

Large-Universe (Multi-Authority) ABE from LWE.
In Submission, 2025

Homomorphic Encryption-based Functional Fair Exchange for arbitrary functions.
IEEE S&P (Oakland), 2026

Performance Benchmarking of Plonky2 and Plonky3 zkSNARK libraries.
0xPARC Foundation, 2025

ZK circuits in Circom.
2025

Yao's Garbled Circuits.
2025

Functional Encryption-based Functional Fair Exchange for linear functions.
ACM CCS, 2024

EIP-2537 compliant precompile for BLS12-381 curve ops and BLS signatures.
Algorand, 2021

Talks

New Constructions of Functional Adaptor Signatures: Broader Functions and Improved Efficiency.
IEEE S&P: May 2026

Functional Fair Exchange: Beyond All-or-Nothing Data Exchange.
BU Security Seminar: February 2026
Yale Applied Cryptography Seminar: January 2026

Fully Adaptive Decentralized MA-ABE: Simplified, Optimized, ASP Supported.
UC Berkeley Crypto Seminar: November 2025
Stanford Security Seminar: October 2025
NTT Research CIS Seminar: October 2025
CMU Crypto Seminar: September 2025

Fair Exchange on Blockchains.
Invited Lecture at University of Utah: October 2024

Functional Adaptor Signatures: Beyond All-or-Nothing Blockchain-based Payments.
ACM CCS: October 2024

Non-Interactive Anonymous Router with Quasi-Linear Router Computation.
IACR TCC: December 2023
Ph.D. Qualifying Exam, CMU : November 2022

Multi-Client Inner Product Encryption: Function-Hiding Instantiations Without Random Oracles.
IACR PKC: May 2023
CMU Theory Lunch: April 2023

Multi-Input Inner Product Encryption: Function-Hiding Instantiations without Random Oracles.
Masters thesis defense, CMU : November 2021

Attribute-based Signatures for Unbounded Circuits in the Random Oracle Model.
Cryptography Reading Group, IITM : July 2020

Obfuscation of Probabilistic Circuits and Applications.
Course Project for Computing on Encrypted Data, IITM : November 2019

Two case studies on advances in Blockchains: Algorand, Zcash.
Seminar Talk for National Blockchain Project, IITK : April 2018

Fully Homomorphic Encryption.
Course Project for Linear Algebra Tools for Theoretical CS, IITK : April 2018

On Lattices, Learning With Errors, Random Linear Codes, and Cryptography.
Course Project for Quantum Computing, IITK : October 2017

Research Experience

Research Intern

NTT Research

Jun 2025 – Aug 2025 Sunnyvale

Pioneered new attribute-based encryption schemes that expanded functionality and significantly improved efficiency, advancing the practicality of lattice-based cryptography

Research Intern

0xPARC Foundation

Mar 2025 – May 2025 Pittsburgh

Benchmarked modern zero-knowledge proof systems (Plonky2/Plonky3), providing performance insights to guide practical adoption of advanced cryptographic protocols

Research Intern

NTT Research

Jun 2024 – Aug 2024 Sunnyvale

Developed foundational advances in multi-authority attribute-based encryption by proving full adaptive security for the classic Lewko–Waters scheme and designing the first scheme for Arithmetic Span Programs

Intern - Smart Contracts Researcher

Theory Group, Algorand

May 2021 – Aug 2021 Pittsburgh

Investigated cryptographic tools needed to enable building complex and powerful Layer 2 Smart Contracts in AlgoClarity (Algorand’s version of the Clarity Smart Contract Language).

Research Assistant

Cryptography Group, IIT Madras

Aug 2019 – Jun 2020 Chennai

Designed a blockchain-based voting system with support for vote verification to enable voters to vote from anywhere with the goal of increasing voter turnout.