About

I am an M.S. student in Mathematics at the University of Minnesota, Twin Cities, co-advised by Professor Nick Hopper and Professor Andrew Odlyzko. Before that, I received my B.S. in Mathematics from the University of Washington, Seattle.

My research interests are in cryptography, applied cryptography, and techniques related to privacy and security.

I am also working on zero-knowledge proofs for LLMs at MARS V in Oxford, advised by James Petrie.

Publications and preprints

  1. Reliable Non-Leveled Homomorphic Encryption for Web Services

    Baigang Chen and Dongfang Zhao

    The ACM Web Conference (WWW), 2026, pp. 3171–3182.

    [Paper]

  2. Closing the Loop: Bidirectional Fully Encrypted Protocols

    Baigang Chen and Nicholas Hopper

    Preprint, 2026. arXiv:2609.17397.

    [Preprint] [Code]

  3. G-Lox: Group-Adaptive, Privacy-Preserving Bridge Distribution with Two-Party Computation

    Baigang Chen and Nicholas Hopper

    Preprint, 2026. arXiv:2606.19620.

    [Preprint] [Code]

Research experience

Zero-Knowledge Proofs for LLMs

James Petrie · MARS V, Oxford · July 2026–present

Designing protocols for proving claims about large language models without revealing the model architecture, drawing on work including Ligero and zkLLM.

Bidirectional Fully Encrypted Protocols

Nick Hopper · University of Minnesota · July 2026–present

Extending fully encrypted protocols to bidirectional communication with public emission and close schedules. Dummy transmissions preserve the prescribed traffic shape when application data are unavailable. [Code]

Order-Revealing Homomorphic Encryption

Dongfang Zhao and Nick Hopper · October 2025–April 2026

Investigated comparison over encrypted data using TFHE-style programmable bootstrapping and a proof-gated comparison pipeline. [Code]

Revisiting rBridge / G-Lox

Nick Hopper · University of Minnesota · September 2025–April 2026

Designed and analyzed a group-adaptive bridge distribution system using two servers and secure computation to hide group state and bridge assignment logic. Studied privacy and system tradeoffs under Sybil enumeration and censor-driven bridge discovery. [Code]

Toward Non-Leveled Approximating FHE

Dongfang Zhao · University of Washington, HPDIC · May–November 2025

Constructed a non-leveled CKKS prototype using a fixed module and error correction. Related work was presented as a poster at USENIX Security 2025 and published at WWW 2026.

Earlier projects

  • Managing Delays in Public Transit Systems. With Giovanni Inchiostro at the University of Washington, March–June 2025. Developed models and tested algorithms for transit delay management. [Code]
  • Fourier Analysis and Applications. With F. Alberto Grünbaum at UC Berkeley, May–July 2024. Studied Fourier analysis and mathematical physics, and investigated Fourier-based approaches to the AKS primality test.

Mentoring and academic activities

  • Directed Reading Project mentor, October 2025–January 2026. Guided reading of Boneh and Shoup’s A Graduate Course in Applied Cryptography, culminating in a presentation on the baby-step–giant-step algorithm.
  • Seminars: étale cohomology with Kai-Wen Lan; anonymous communications with Megumi Ando; the Burnside problem with Be’eri Greenfeld; and public-key cryptography with Michael Naehrig and Natalie Naehrig.
  • Annual Dean’s List, University of Washington, 2023–2024.