Since February 2025
Zellic
I review smart contracts and off-chain code at Zellic, including compilers and virtual machines written in C, C++, and Rust. My work includes finding bugs, checking their impact, and recommending fixes.
Experience →Security researcher.
Hi, I'm Quentin. I work at Zellic and co‑founded BEYOND.I audit smart contracts, compilers, and virtual machines. I compete in world-class CTFs with The Hacker Crew and DeFiHackLabs.
3rd · StarkWare Perps9,397.98 USDC · Cairo / perpetuals 1st · vVv Launchpad94.59 USDC · Token distribution Size · 2 high findings1,903.96 USDC · 16th place
Competitions & challenges
Audit competitions
$12.59K in contest earnings · 10 high / 13 medium findingsRecorded by Sherlock · 10 payouts · snapshot: 23 September 2026
Scroll the table sideways for findings, awards, and credit →
| Place | Competition / scope | Award | Findings | Credit |
|---|---|---|---|---|
| 3rd | StarkWare Perps ↗Code4rena · Mar–Apr 2025 Cairo / perpetuals | 9,397.98 | 1 high 1 medium | m4k2 |
| 1st | vVv Launchpad ↗Sherlock · Nov 2024 Investments & token distribution | 94.59 | 1 high | m4k2Individual profile award |
| 16th | Size ↗Code4rena · Jun 2024 EVM / lending | 1,903.96 | 2 high | m4k2 |
| 7th | Lambo.win ↗Code4rena · Dec 2024 EVM / token launchpad | 388.43 | 2 high 3 medium | m4k2 |
| 15th | Dria ↗CodeHawks · Oct 2024 LLM oracle coordination | 98.47 | 2 high 3 medium 2 low | m4k2xmkShared account result |
CTFs
I play with The Hacker Crew and DeFiHackLabs.
- OnlyPwner · joint highest score ↗230 points · 17 challenges solved · individual leaderboard snapshot, 23 Sep 2026
- The Hacker Crew · global team #1 in 2025 ↗Global team #3 in 2024 · member since 2023
- HITCON CTF 2024 · on-site finalistTaipei, Taiwan · with The Hacker Crew
- PwnMe CTF 2025 · on-site finalistParis, France · with The Hacker Crew
- Immunefi ETH Escape 2024 · on-site finalistBangkok, Thailand · individual competition
I've also played Paradigm CTF and Blaz CTF with DeFiHackLabs, and competed in Curta.
Challenges I've written
I wrote Opaze Whisperer for REMEDY CTF, an EVM challenge built around jump-oriented programming and bytecode manipulation.
- REMEDY CTF · Opaze Whisperer ↗EVM reverse engineering, bytecode manipulation, and jump-oriented programming.
- GCC CTF 2024 & Crew CTF 2024Challenge author.
- Breizh CTF 2023Challenge author · 700 on-site participants.
Work
Co-founder
BEYOND
I co-founded BEYOND, a blockchain security research team. Our public portfolio includes audit reports and contest results.
Team portfolio ↗Independent research
Audits & contests
I've worked on private audits, both independently and in teams. For public findings and rankings, start with the contest results above.
Contest results ↑REMEDY CTF
Opaze Whisperer
My EVM reverse-engineering challenge. The write-up covers its bytecode, JOP gadgets, and custom VM. I also gave a talk walking through it.
Read the write-up ↗Technical focus
Smart contracts
EVM internals, contract logic, and low-level code. My work covers EVM, Move, Cairo, and Bitcoin ecosystems.
Solidity / Cairo / Huff / Yul / GeasCompilers & systems
Compiler and VM security, reverse engineering, and off-chain C, C++, and Rust code.
Ghidra / IDA / Dedaub / EreverTesting
I use fuzzing and symbolic testing alongside manual review.
Foundry / Echidna / HalmosWriting & talks
Eight Bytes to Burn a Bridge
My article on Relay Protocol’s legacy Bitcoin sighash bug: UTXO value validation and cross-chain signing.
Reverse/Pwn de Smart Contract en CTF
Recorded talk in French on EVM reverse engineering and Opaze Whisperer.
Illusion of Immutability
CREATE2, CREATE, and SELFDESTRUCT in a MidnightCTF challenge.
JOP Down the Rabbit Hole
The Opaze Whisperer write-up: bytecode manipulation, JOP, and a custom VM.
hxp 38C3: Respectable NFT
EVM smart-contract challenge analysis.
Blaz CTF: Jambo, Maze, Ghost
EVM reverse engineering and low-level Solidity/Yul.
HeroCTF V5: Blockchain challenges
Contract decompilation and Foundry-based challenge solutions.
About me
I started studying blockchain security independently in 2022. Since then, I've competed in audit contests and CTFs, written challenges, and shared my work through posts and talks.
Before joining Zellic, I researched privacy and obfuscation in decentralized systems for the French Government. At Crédit Mutuel Arkéa's CERT/SIRT, I worked on threat intelligence, built a crisis-management tool, and set up a forensic laboratory.
I've also designed and developed a multi-layered privacy circuit using decentralized technologies.
My degrees are in computer science and electronics, including an M.S. in Computer Science at ENSIBS, a B.S. in Software Engineering, and a B.S. in Industrial Electronics and Computer Engineering.
I was a firefighter from 2016 to 2023. That included rescue operations, road rescues, and urban and forest fires.
- FEB 2025 — PRESENTSecurity Researcher · Zellic
Smart contracts, compilers, VMs, and off-chain systems.
- SEP 2024 — PRESENTIndependent security research
Audit contests and private reviews, solo and with teams.
- SEP 2023 — SEP 2024Research Intern · French Government
Privacy and obfuscation in decentralized systems.
- SEP 2021 — SEP 2023Research Intern · Crédit Mutuel Arkéa
CERT/SIRT, threat intelligence, crisis-management tooling, and forensics.
Want to discuss a review?
Email me with the project and scope.
Europe · CET / CEST · French & English