Zhenfei Zhang

Cryptographer, zhangzhenfei@gmail.com Rust developer, https://zhenfeizhang.github.io/ Advisor, https://www.linkedin.com/in/zhenfeizhang/ Angel
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Experience

Cryptography engineer, Scroll tech, 2022-now

Cryptography researcher, Ethereum Foundation, 2021-now

Staff cryptographer, Espresso System, 2021-2022

CTO and co-founder, Manta Network, 2021

Cryptography Engineer, Algorand, 2018-2020

Director of Cryptography Research, Security Innovation -> OnBoard Security, 2014-2018

Advisorship

Cysic, hardware accelerating ZKP. (Founding Advisor)

Modulus Labs, Putting Powerful ML Models On-Chain.

Nexus, Enabling Verifiable Computing.

Polyhedra, Infrastructure for Web3 Interoperability.

Highlights

Unique skill
full stack cryptographer:
Eureka -> academic paper -> spec -> poc -> standard -> code -> product
Competitions
Winner of Zprize 2023: Accelerating the Poseidon Hash Function
Falcon is a NIST post-quantum cryptography standard.
LAC won the first prize of Chinese post-quantum cryptography competition.
Standards
Internet draft: BLS-signature (“Ethereum 2.0 is not possible without BLS”)
Internet draft: Quantum safe hybrid for TLS 1.2 and TLS 1.3.
Publication
30+ peer reviewed paper at Eurocrypt 2023, Usenix 2023, ACM CCS 2023, 2022, 2020, Asiacrypt 2019, Crypto 2019, Asiacrypt 2018, PKC 2020, 2018, etc.;
See next pages for full list.
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Open sourced libraries

HyperPlonk
Plonk with Linear-Time Prover and High-Degree Custom Gates. Source code.
VeriZexe
achieving functional privacy for smart contracts. Source code.
Jellyfish
a rust implementation of plonk zero-knowledge proof system. Source code. Also comes with a solidity verifier.
Falcon.rs
Falcon written in R1CS and Plonkish circuits for ZKP applications. Source code.
Bandersnatch
a fast elliptic curve built over the BLS12-381 scalar field; build with Arkworks framework; improves group operations by 42%; reduces R1CS size by 20%; reduce Plonk circuit size by 10%. Source code.
Manta
A privacy preserving decentralized exchange protocol using zkSNARKs; also a parachain build on top of the polkadot ecosystem. Source code.
Zen
A privacy preserving machine learning framework for convolutional neural networks, build with zkSNARKs. Source code.
Pixel
A pairing based, forward-secure and aggregatable signature, written in python (PoC) and rust (product level). Improves existing (non-aggregatable) solution by 100x, open sourced and external audited. Source code.
Pointproofs:
A pairing based, aggregatable prove system over multiple vector commitments, written in rust (product level). Source code.
Raptor
A lattice based (linkable) ring signature, written in C as a PoC, aiming to protect user’s anonymity against quantum adversaries. Source code.
NTRUEncrypt
A C implementation of NTRUEncrypt, submitted to NIST PQC standardization process. Source code.
Ring multiplication
A C library for fast ring multiplication using AVX-2; improving prior codes by a factor of 2.23. Source code

Education

2010-2014
PhD, Computer Science, University of Wollongong, Australia;

Thesis title: Revisiting Fully Homomorphic Encryption Schemes and Their Cryptographic Primitives

2008-2009
Master of Engineering - Research, University of Wollongong, Australia;
2007
Master of Internet Technology, University of Wollongong, Australia;
2001-2005
Bachelor of Computer Science, BeiHang University, China.


















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See next pages for the full list of patents, standards and publications.
\pagebreak

Patents

  • Chameleon Hash technique and linkable ring signature technique
    • Zhenfei Zhang
    • Provisional patent, 2018.
  • Digital signature technique
    • Jeffrey Hoffstein, Jill Pipher, William J Whyte, Zhenfei Zhang
    • United States Patent Application, 2018.
  • Digital signature method and apparatus
    • Jeffrey Hoffstein, Jill Pipher, Joseph H Silverman, William J Whyte, Zhenfei Zhang
    • United States Patent 15530762, 2017.

Standards

  • BLS Signature Scheme
    • D. Boneh, S.Gorbunov, R. Wahby, H.Wee, Z.Zhang
    • Internet-Draft.
  • Quantum-Safe Hybrid (QSH) Ciphersuite for Transport Layer Security (TLS) version 1.2
    • J. M. Schanck, W. Whyte and Z. Zhang
    • Internet-Draft.
  • Criteria for selection of public-key cryptographic algorithms for quantum-safe hybrid cryptography
    • J. M. Schanck, W. Whyte and Z. Zhang
    • Internet-Draft.
  • Quantum-Safe Hybrid (QSH) Ciphersuite for Transport Layer Security (TLS) version 1.3
    • W. Whyte, Z. Zhang, S. Fluhrer and O. Garcia-Morchon
    • Internet-Draft.
  • Efficient Embedded Security Standards (EESS) #1: Implementation Aspects of NTRUEncrypt
    • W. Whyte and Z. Zhang
    • Consortium for Efficient Embedded Security
  • Quantum Safe Cryptography and Security; An introduction, benefits, enablers and challenges
    • One of 22 contributors
    • European Telecommunications Standards Institute(ETSI) white paper
\pagebreak

Publications

2023

  • Chipmunk: Better Synchronized Multi-Signatures from Lattices
    • Nils Fleischhacker, Gottfried Herold, Mark Simkin and Zhenfei Zhang
    • ACM CCS 2023.
  • HyperPlonk: Plonk with Linear-Time Prover and High-Degree Custom Gates
    • Binyi Chen, Benedikt Bünz, Dan Boneh and Zhenfei Zhang
    • Eurocrypt 2023. IACR eprint, github.
  • VERI-ZEXE: Decentralized Private Computation with Universal Setup
    • Alex Luoyuan Xiong, Binyi Chen, Zhenfei Zhang, Benedikt Bünz, Ben Fisch, Fernando Krell and Philippe Camacho
    • Usenix Security 2023. IACR eprint. Github.

2022

  • Squirrel: Efficient Synchronized Multi-Signatures from Lattices.
    • Nils Fleischhacker, Mark Simkin and Zhenfei Zhang
    • ACM CCS 2022. IACR eprint. Github.
  • Post-Quantum Verifiable Random Function from Symmetric Primitives in PoS Blockchain
    • Maxime Buser and Rafael Dowsley and Muhammed F. Esgin and Shabnam Kasra Kermanshahi and Veronika Kuchta and Joseph K. Liu and Raphael Phan and Zhenfei Zhang
    • ESORICS 2022. IACR eprint.

2021

  • Bandersnatch: a fast elliptic curve built over the BLS12-381 scalar field
  • Manta: a Plug and Play Private DeFi Stack
  • Practical Post-Quantum Few-Time Verifiable Random Function with Applications to Algorand
    • Muhammed F. Esgin and Veronika Kuchta and Amin Sakzad and Ron Steinfeld and Zhenfei Zhang and Shifeng Sun and Shumo Chu
    • Financial Cryptography 2021. IACR eprint. Source code.
  • TensorCrypto
  • Hybrid Dual Attack on LWE with Arbitrary Secrets
  • ZEN: Efficient Zero-Knowledge Proofs for Neural Networks

2020

  • Manta: Privacy Preserving Decentralized Exchange
  • Pointproofs: Aggregating Proofs for Multiple Vector Commitments
  • MPSign: A Signature from Small-Secret Middle-Product Learning with Errors
    • Shi Bai, Dipayan Das, Ryo Hiromasa, Miruna Rosca, Amin Sakzad, Damien Stehle, Ron Steinfeld, Zhenfei Zhang
    • PKC 2020. IACR eprint. Source code
  • Modular Lattice Signatures, revisited
    • Dipayan Das, Jeffrey Hoffstein, Jill Pipher, William Whyte, Zhenfei Zhang
    • Design, Codes and Cryptography. IACR eprint. Source code.
    • 1st round, NIST post-quantum cryptography standardization process.

2019

  • Middle-Product Learning with Rounding Problem and its Applications
    • Shi Bai, Katharina Boudgoust, Dipayan Das, Adeline Roux-Langlois, Weiqiang Wen, Zhenfei Zhang
    • Asiacrypt 2019. IACR eprint.
  • Efficient Lattice-Based Zero-Knowledge Arguments with Standard Soundness: Construction and Applications
    • Rupeng Yang, Man Ho Au, Zhenfei Zhang, Qiuliang Xu, Zuoxia Yu, William Whyte
    • Crypto 2019. IACR eprint.
  • (Linkable) Ring Signature from Hash-Then-One-Way Signature
    • Xingye Lu, Man Ho Au, Zhenfei Zhang
    • TrustCom 2019. IACR eprint.
  • Ring Signatures based on Middle-Product Learning with Errors Problems
    • Dipayan Das, Man Ho Au, Zhenfei Zhang
    • Africacrypt 2019.
  • Raptor: A Practical Lattice-Based (Linkable) Ring Signature
  • Round5: Compact and Fast Post-Quantum Public-Key Encryption
    • Hayo Baan, Sauvik Bhattacharya, Scott Fluhrer, Oscar Garcia-Morchon, Thijs Laarhoven, Ronald Rietman, Markku-Juhani O. Saarinen, Ludo Tolhuizen, Zhenfei Zhang
    • PQCrypto 2019. IACR eprint. Website.
    • 2nd round, NIST post-quantum cryptography standardization process.
  • Cryptanalysis of an NTRU-based Proxy Encryption Scheme from ASIACCS’15
    • Zhen Liu, Yanbin Pan, Zhenfei Zhang
    • PQCrypto 2019. IACR eprint.

2018

  • LAC: Practical Ring-LWE Based Public-Key Encryption with Byte-Level Modulus
  • Shorter Messages and Faster Post-Quantum Encryption with Round5 on Cortex M
    • Markku-Juhani O. Saarinen, Sauvik Bhattacharya, Oscar Garcia-Morchon, Ronald Rietman, Ludo Tolhuizen, Zhenfei Zhang
    • Cardis 2018. IACR eprint.
  • On the Hardness of the Computational Ring-LWR Problem and its Applications
    • Long Chen, Zhenfeng Zhang, Zhenfei Zhang
    • Asiacrypt 2018. IACR eprint.
  • A signature scheme from the finite field isomorphism problem.
  • Practical Signatures from the Partial Fourier Recovery Problem Revisited: A Provably-Secure and Gaussian-Distributed Construction.
    • Xingye Lu, Zhenfei Zhang, Man Ho Au
    • ACISP 2018.
  • Optimizing polynomial convolution for NTRUEncrypt.
  • Fully Homomorphic Encryption from the Finite Field Isomorphism Problem.
    • Yarkin Doröz, Jeffrey Hoffstein, Jill Pipher, Joseph H. Silverman, Berk Sunar, William Whyte, Zhenfei Zhang:
    • PKC 2018. IACR eprint.

2017

  • Choosing parameters for NTRUEncrypt
    • Jeffrey Hoffstein, Jill Pipher, John M. Schanck, Joseph H. Silverman, William Whyte, Zhenfei Zhang
    • CT-RSA 2017. IACR eprint.
  • Round2: KEM and PKE based on GLWR.
    • Hayo Baan, Sauvik Bhattacharya, Óscar García-Morchón, Ronald Rietman, Ludo Tolhuizen, Jose Luis Torre-Arce, Zhenfei Zhang
    • NIST PQC submission. IACR eprint.
  • A signature scheme from Learning with Truncation.
    • Jeffrey Hoffstein, Jill Pipher, William Whyte, Zhenfei Zhang
    • Pre-print. IACR eprint.
  • Anonymous Announcement System (AAS) for Electric Vehicle in VANETs.
    • Man Ho Au, Joseph K. Liu, Zhenfei Zhang, Willy Susilo, Jin Li
    • The Computer Journal.

2016

  • Circuit-extension handshakes for Tor achieving forward secrecy in a quantum world.
  • NTRU modular lattice signature scheme on CUDA GPUs.
    • Wei Dai, Berk Sunar, John M. Schanck, William Whyte, Zhenfei Zhang
    • HPCS 2016. IACR eprint.

2015 and earlier

  • LLL for ideal lattices: re-evaluation of the security of Gentry-Halevi’s FHE scheme.
    • Thomas Plantard, Willy Susilo, Zhenfei Zhang
    • Design, Codes and Cryptography.
  • DA-Encrypt: Homomorphic Encryption via Non-Archimedean Diophantine Approximation.
    • Jeffrey Hoffstein, Jill Pipher, John M. Schanck, Joseph H. Silverman, William Whyte, Zhenfei Zhang
    • Pre-print. IACR eprint.
  • Fully Homomorphic Encryption Using Hidden Ideal Lattice.
    • Thomas Plantard, Willy Susilo, Zhenfei Zhang
    • IEEE Transation on Information Forensics and Security.
  • Adaptive Precision Floating Point LLL.
    • Thomas Plantard, Willy Susilo, Zhenfei Zhang
    • ACISP 2013.
  • On the CCA-1 Security of Somewhat Homomorphic Encryption over the Integers.
    • Zhenfei Zhang, Thomas Plantard, Willy Susilo
    • ISPEC 2012.
  • Lattice Reduction for Modular Knapsack.
    • Thomas Plantard, Willy Susilo, Zhenfei Zhang
    • SAC 2012.
  • Reaction Attack on Outsourced Computing with Fully Homomorphic Encryption Schemes.
    • Zhenfei Zhang, Thomas Plantard, Willy Susilo
    • ICISC 2011.