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Danny Willems

Independent Cryptography Researcher and Engineer at BaDaaS

For the most up-to-date overview of my work, see my GitHub, LinkedIn, and Twitter profiles.

Mathematician and engineer with 10+ years of experience in cryptography research, infrastructure, and production systems. First engineer at B2C2, one of the earliest institutional crypto liquidity providers (acquired by SBI Holdings in 2020), leading the real-time accounting systems, blockchain node infrastructure for real-time transaction monitoring, and exchange interfaces for PnL detection. Co-founder of LeakIX, an attack surface management platform serving 100+ clients and multiple national CERTs. Cryptography researcher and engineer at o1Labs (Mina Protocol), and led a team to reimplement the node in Rust. Contributed to core cryptographic infrastructure and the protocol itself at Nomadic Labs (Tezos), and co-authored peer-reviewed publications on arithmetization-oriented hash functions and PlonK optimizations. Research interests include SNARK-friendly primitives based on elliptic curves and incrementally verifiable computation. Currently running BaDaaS, an independent mathematics research boutique, building tools to formally verify the world's cryptographic knowledge.

Professional Experience

BaDaaS
Independent Researcher & Engineer

BaDaaS is a Belgium-based mathematics research boutique founded in 2020, bridging abstract mathematics and concrete applications. Currently specialized in cryptography, formal verification, and distributed systems. Consulting, research, and engineering for protocol design, cryptographic library development, and security auditing.

Current projects:

  • Papyrus: a pipeline to convert, validate, and extract structured mathematical knowledge from cryptographic research papers, building toward the first formally verified knowledge base of the field.
  • cryptography.academy: the web frontend for the Papyrus pipeline, presenting all extracted and verified cryptographic knowledge in a unified, searchable interface.
  • LeakIX: co-founded attack surface management platform combining a search engine indexing public information and an open reporting platform for vulnerability disclosure.
o1Labs
Head of Cryptography (Architect) & Rust Node Team Lead
Senior Cryptography Engineer

o1Labs incubated the Mina Protocol, a layer-1 blockchain using zero-knowledge proofs for succinctness.

As Head of Cryptography, oversaw the cryptography architecture across an engineering team of 15-20 people, and led a team of up to 5 engineers on the full rewrite of the Mina node from OCaml to Rust.

As Senior Cryptography Engineer, contributed to o1VM, a zkVM for MIPS built as a team effort. Implemented the RISC-V interpreter, focused on the folding aspect, and designed and started building Arrabbiata, a folding scheme for arbitrary custom gates and degrees. Contributed to Pickles, the recursion layer used in Mina based on Halo2 (Plonk-ish implementation of Halo), and to the proof-systems library (Kimchi, custom gates, lookups).

LeakIX
Co-founder/CEO

Co-founded with Gregory Boddin. LeakIX is an attack surface management platform combining a search engine that indexes public information by scanning the Internet and an open reporting platform for vulnerability disclosure. Serving 100+ clients and multiple national CERTs.

Our goal is prevention: we intend to provide a preemptive solution by trusting individual researchers and security companies on the most sensitive data we index. We deliver clear incident reports, help identify what information has or could be affected, and explain how to resolve the issue. All voluntary reports are free and no sales attempts are made on LeakIX’s side. We ban sales attempts that take advantage of incidents to sell shady security services.

Nomadic Labs
Cryptography Engineer

Nomadic Labs are Tezos blockchain experts. Cryptography engineer in the cryptography team, contributing to the Tezos protocol and its zero-knowledge research and development.

  • Co-authored the Anemoi/Jive paper on arithmetization-oriented hash functions for PlonK-based systems. Focused on implementation and CPU optimizations.
  • Co-authored the PlonK optimizations paper. Focused on implementation.
  • Built and maintained the ocaml-bls12-381 ecosystem: pairing operations, BLS signatures, and hash functions over BLS12-381.
  • Contributed to Plompiler, a monadic DSL for building aPlonK circuits.
  • Worked on Epoxy, a validity rollup for the Tezos protocol.
  • Contributed directly to the Tezos protocol (Octez).

Also enrolled at Institut Polytechnique de Paris (IPP) for a PhD on SNARK-friendly primitives based on elliptic curves, under the direction of Benjamin Smith (INRIA, Ecole Polytechnique). Discontinued to join o1Labs.

B2C2
Blockchain Lead & Software Engineer

First engineer at B2C2, one of the earliest institutional crypto liquidity providers, later acquired by SBI Holdings in 2020. B2C2 serves brokers, exchanges, hedge funds, and family offices worldwide with 24/7 crypto and fiat liquidity.

Led the real-time accounting and risk infrastructure:

  • Built and operated a fleet of blockchain nodes across multiple chains for real-time transaction monitoring.
  • Developed the real-time crypto/fiat accounting system with PnL detection, integrated with the risk system.
  • Built exchange interfaces for automated trade reconciliation.
  • Managed the full lifecycle: infrastructure, development, releases, and new features for the blockchain and accounting projects.
  • Contributed to parts of the trading system.
Earlier experience (2015-2016)
Be Sport
Intern

Social network around sports. The platform is built using OCaml and the Ocsigen technology. During the internship, I was responsible to improve the framework Ocsigen Start, which consists of a template to bootstrap a complete standard application requiring user management, displaying tips, and sending notifications to the users.

Selfpharma
Cordova Mobile Application Engineer

Online pharmacy shop based in Brussels, Belgium, built using Prestashop. Leading the iOS and Android mobile applications development, written in Cordova.

INRIA Paris
Research Intern - Gallium Team

Research internship in the Gallium team, focusing on module systems in functional programming languages.

Education

PhD Candidate in Cryptography (not completed) @ Institut Polytechnique de Paris (IPP)

Topic: SNARK-friendly primitives based on elliptic curves. Under the direction of Benjamin Smith (INRIA, Ecole Polytechnique). Discontinued to join o1Labs.

Master's Degree Mathematics and Computer Sciences @ University of Mons

Grade: Summa Cum Laude

Bachelor degree: minor in Physics. Awarded with the prize of the Mathematics Department.

Piscine C @ 42

Piscine C in July 2014, joined in 2015. Stopped 1 year after to focus on master degree in mathematics at UMONS.

Research Publications

New Design Techniques for EfficientArithmetization-Oriented Hash Functions: Anemoi Permutations and JiveCompression Mode
Clémence Bouvier and Pierre Briaud and Pyrros Chaidos and Léo Perrin andRobin Salen and Vesselin Velichkov and Danny Willems
New optimization techniques for PlonK'sarithmetization
Miguel Ambrona, Anne-Laure Schmitt, Raphael R. Toledo, and Danny Willems
PDF
To a typed language for modular programming (2016-2017)
Danny Willems, master thesis directed by François Pottier

Public Talks

ZK11: o1VM: Building a Real-World zkVM for MIPS
Danny Willems
A zkVM for the MIPs architecture and OP fault proofs
Danny Willems
ZKProof5 - Anemoi & Jive: New Arithmetization-Oriented tools for Plonk app
Clémence Bouvier and Danny Willems

Notable Open Source Contributions

cryptography.academy: formally verified cryptographic knowledge base (2025 - Present)
mina-rust: full rewrite of the Mina Protocol node in Rust (2025 - 2026)
proof-systems: zero-knowledge proof systems library at o1Labs (2023 - 2026)
o1VM: a zkVM for MIPS (2023 - 2025)
Arrabbiata: a folding scheme for arbitrary custom gates and degrees (2024 - 2025)
Pickles: recursion layer for the Mina Protocol (2023 - 2025)
Octez: an OCaml implementation of the Tezos protocol (Dec 2019 - 2023)
ocaml-bls12-381: an efficient OCaml implementation of the pairing-friendly curve BLS12-381 (January 2020 - 2023)
ocaml-bls12-381-hash: efficient C and OCaml implementation of hash functions over the scalar field of BLS12-381 (Aug. 2022 - 2023)
ocaml-bls12-381-signature: OCaml implementation of BLS signature for BLS12-381 (June 2021 - 2023)
Plompiler: a monadic Domain Specific Language embedded in OCaml than can be used to build circuits for aPlonK (2021 - 2023)
Mec: Modular Experimental Cryptography library in OCaml (April 2020 - 2023)
ocaml-ff: Finite Field library in OCaml (April 2020 - 2023)
ocaml-polynomial: polynomial over finite fields in OCaml (April 2020 - 2023)
ocaml-chia-vdf: OCaml wrapper for Chia's class group based VDF (May 2022)
ocaml-carray: contiguous C arrays in OCaml (May 2022 - 2023)
Seum: OCaml DSL and tool to write and compare programs in assembly, in a typed and "safe" fashion way (June 2022 - 2023)
ocaml-arkworks: OCaml binding to Rust library arkworks (Dec 2022 - 2023)
Ocsigen - Ocsigen Start (July 2016 - Dec 2016)
ocaml-cordova: build mobile applications using OCaml and Cordova