About

Hi, I’m Arthur 👋 #

I’m Arthur, better known online as Vozec. I work as a cybersecurity researcher focused on offensive security, bug bounty, and pentesting.

Most of my day-to-day is finding bugs that matter: chaining unintended behaviors in real-world software, hunting for novel vulnerabilities in CMS/web stacks, and writing reliable exploits.

What I do #

• Bug bounty. Continuous research on public and private programs, with a focus on web, authentication, and deserialization bugs.
• Offensive research. Auditing applications source-to-sink, publishing CVEs and writeups when responsibly disclosed. Recent work: my research on the Jalios CMS and a SPIP pre-auth RCE .
• Pentesting. External, internal, and web-application engagements; reporting in a way that’s actionable for the dev teams on the other side.

CTF & community #

I play CTFs whenever I can: FCSC, PwnMe, leHACK, insomni’hack, and many one-shots. The Writeups section covers most of what I’ve solved and felt worth writing up. The articles in RSA , AES , and Crypto Other are deeper dives into the cryptography I love: RSA attacks, AES cryptanalysis, lattice basics, ECC.

Where to find me #

• GitHub → Vozec (tools, exploits, libraries)
• Root-Me → Vozec (challenges & ranking)
• LinkedIn → arthur-dlfr
• Twitter / X → @Vozec1

Open-source tools #

A non-exhaustive list of things I’ve built and shared.

🔒 Cryptography #

• Feal ALL : Python implementation of the three FEAL versions.
• AES DFA : differential fault analysis on AES-128.
• AES Square Attack : square attack on AES-128.
• AES Flipper : AES-CBC bit-flipping attack.
• AES ECB Padding attack : ECB padding-oracle attack.
• AES CBC Padding attack : CBC padding-oracle attack.
• RSA PKCS1.5 Padding attack : Bleichenbacher’s attack on RSA PKCS1.5.
• AES Sage 128 : classic AES-128 built on top of Rijndael-GF (SageMath).
• Cryptolib : my personal cryptography library.
• DLP Solver : multiple algorithms for the discrete-logarithm problem.
• Facto4CTF : RSA public-key factoring with several methods.
• Vigenere Plaintext Attack : Vigenère breaker with known plaintext.

🔨 Reverse engineering #

• BrainDbg : Brainfuck debugger in Python.
• RevBrain : automated crack resolution for CTF.
• HSPAL Decompiler : decompiler for the HSPAL esolang.

🚩 CTF tooling & misc #

• CTFilesScan : web app gathering common file-analysis methods for CTF.
• Discord CTFD Parser : auto-creates Discord rooms from a CTFD platform.
• Discord Multi Account Detector : reliability score for Discord accounts.
• CTFd Tracker : cheating detection on CTFD-based events.
• Ctfd Account Creator : quick team registration on CTFD.