Bug bounty writeup 🤍👌🏻

All my certificates in 2025 🤍

عام جديد سعيد لكم و ب اذن الله من تطور لي تطور لنا جميعا 🤍

بعد ما راجعت و اتاكد اتعلمت حاجه جديده اني مش استعجل علي الحاجه

صحيح شكلها يبان انها فعلا xss بس الحقيقه لا و هربط مقوله دي بكل شئ

طلما مفيش impact مفيش Vulnerability


العيب مش فل غلط العيب اني اصحح الغلط و المره الجايه هتاكد ميت مره و شكرا لكل واحد قالي كلمه كويسه و شكرا بردو الي قلي كلمه وحشه

ف لاتنين انا اتعلمت و استفدت

و انت اكيد يلي بتقراء استفدت من الموقف دا و اشوفكم على خير 🤍✌🏻

🚩 New CTF Writeup – Breizh CTF


I’ve just published a technical writeup for the Authentification challenge from Breizh CTF, focusing on a flawed implementation of AES-GCM at the counter management level.


This is not just about “nonce reuse is bad”.


The writeup walks through how :


Misusing the J₀ counter


Breaks both confidentiality and integrity
Allows recovery of the GHASH key (H)


And enables full forgery of a valid admin token


The goal was to explain why this class of bugs is terminal in AEAD schemes, not just how to exploit it.


🔗 Full writeup on Medium :


https://spider1sec.medium.com/breizh-ctf-authentification-9707750140bc


#BreizhCTF #CTF #Cryptography #AESGCM #CyberSecurity #InfoSec #Writeup #Medium

Quo vadis? — ECSC 2024 (Italy)

I recently solved “Quo vadis?”, a cryptography challenge from ECSC 2024 (Italy), published on CryptoHack.
The challenge was solved by only 8 participants, and I also wrote a full technical write-up explaining the solution in depth.

What made this challenge special wasn’t implementation difficulty, but the core idea :

Working with Galois Rings rather than common finite fields
Exploiting isomorphisms between different ring constructions
Reducing the problem to linear algebra over ℤ / 2ᵏℤ
Using Newton lifting to move solutions across ring levels

This was a reminder that advanced crypto CTFs are often less about tools, and more about mathematical understanding and clean reasoning.

I shared a detailed write-up covering:

The mathematical insight behind the challenge

The full solving strategy

Implementation details in Sage


🔗 Write-up :

https://spider1sec.medium.com/quo-vadis-ecsc-2024-italy-cryptohack-70cd091be2b8

#Cryptography #AppliedCryptography #Mathematics