Pratyush Ranjan Tiwari

Pratyush Ranjan Tiwari


I am a third year PhD student at Johns Hopkins University under the wonderful supervision of both Matthew Green and Abhishek Jain. I am in general interested in cryptography and its applications, more specifically, most of my research interests are at the intersection of cryptography with privacy, and verifiable computation. I am particularly interested in designing protocols with minimal trust requirements. Over the last two summers, I have collaborated with the Ethereum Research team to build, attack and study practical verifiable delay functions (VDFs) and with the PSE team as a grantee where I fell down the zero-knowledge proofs rabbithole, working on verifiable machine learning.


  • Privacy-preserving computation
  • Zero-knowledge proof applications
  • Verifiable computation


  • PhD in Computer Science, 2025 (expected)

    Johns Hopkins University

  • Ashoka Scholar's Program (1 year Postgrad by research), 2020

    Ashoka University

  • BSc in Mathematics & Computer Science, 2019

    Ashoka University



VDF research


May 2021 – Present
Collaborating with the Ethereum Research team to build, attack and study practical verifiable delay functions (VDFs).

PhD student

Johns Hopkins University

Sep 2020 – Present Maryland, USA
My advisors are Abhishek Jain and Matt Green. Work on Verifiable computation, Post-Quantum cryptography.

Research Assistant

New York University, Abu Dhabi

Jun 2020 – Aug 2020 Virtual
Working on privacy-preserving techniques under Prof. Christina Pöpper at the Cyber Security & Privacy Lab (CSP-lab).

Teaching Assistant

Ashoka University

Aug 2019 – May 2020 India
TA for Prof. Debayan Gupta: (1) Spring 2020: Computer Security & Privacy (2) Fall 2019: A New Geography in the Information Age

Cryptography Engineering Intern


May 2019 – Aug 2019 Germany
Worked on Celo’s Ultralight Client Sync which enables users to download very small number of block headers to verify correctness of current validator set. On the implementation team for Pedersen Hashes, different elliptic curves and bls-zexe in Rust and Sage similar to the ZCash Protocol

Summer Research Intern

IIT Madras

Jul 2018 – Jun 2019 India
Cryptanalysis of Stream Ciphers like Grain 128 and Trivium under Prof. Santanu Sarkar. Worked alongside PhD students to implement 855-round key recovery attack on Trivium. Implementations in C and Sage.


Undergraduate Research Excellence Award

Awarded to the graduating student with the best track record in academic research, evaluated on the basis of publications and thesis quality.

Engineering Fellow: Privacy Preserving Eigenvalue Computation

Celo’s algorithmically volume regulated stablecoin protocol requires each user to calculate their own Eigentrust score. Developing an efficient Zero Knowledge protocol to enable this. Youngest fellow among all the Celo fellows. Usually fellows are advanced Graduate students. Received a $10,000 grant.

Recent Publications

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(2022). Time-Deniable Signatures. in IACR eprint.


(2022). Not So Slowth: Invertible VDF for Ethereum 2.0. in Stanford’s Science of Blockchain Conference (SBC ‘22).


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