SIGSEGv2

J’ai récemment participé aux qualifications pour le CTF SIGSEGv2, un événement qui aura lieu le 30 novembre à Paris. J’aurai l’honneur d’y présenter une conférence autour de l’informatique quantique et de ses impacts sur le monde de la cryptographie.

Read More

TokyoWesterns CTF 2019

In this article, I want to illustrate three levels of solving a crackme problem. The challenge is called Easy Crack Me, from TokyoWesterns CTF 2019. I really enjoyed playing this CTF which was very hard as expected (even the “easy” problems), but I managed to briefly make it to the top 100 even though I was playing alone.

Read More

Twitter Audience Diagrams

Here’s a simple dataviz I made while trying to understand the community behind our Twitter account @h25io. I especially wanted to see where the audience comes from, and how strongly it overlaps with the company’s founders @MathisHammel and @clement_hammel.

Read More

Facebook Hacker Cup 2019 - Qualification round

For the 4th year in a row, I’ve registered for the Facebook Hacker Cup, a great coding competition played in 4 rounds and a final, where my personal goal is to make it to the world’s top 500 to earn a T-shirt. Last year I ended at the 282nd place out of 8200 which wasn’t enough to advance to the last round, but I got the T-shirt ! If I win the same Hacker Cup T-shirt this time, I’ll give it away to one of my Twitter followers who retweets one of my Hacker Cup articles.

Read More

SwampCTF Writeup - Weak AES

It’s been 6 months I haven’t been playing CTFs, mostly due to me graduating INSA and having to leave its academic team InSecurity. But I’m back in the game, so let’s celebrate by breaking some crypto !

Read More

SpamAndFlags CTF Writeup - Fermat's Last Theorem

This weekend, I played SpamAndFlags CTF Teaser 2019, which was a very interesting CTF. I didn’t play for too long, having another CTF and the Google Code Jam quals at the same time, but there was a particular task that I immediately fell in love with : the goal was to find a counter-example to Fermat’s last theorem in order to get a flag.

Read More

Android Reverse Engineering for Data Science

Almost a year ago I started using an app called “Too Good To Go” (this article is not sponsored!). Its goal is to reduce food waste by allowing stores from all around Europe to sell their unsold products to the app users at a very small price. You usually pay 20 to 50% of the retail price, but the products have very short expiration dates and you don’t know what you will get beforehand.

Read More

Battle Dev RegionsJob Novembre 2018 - Problème 5

Il y a quelques semaines s’est tenue la 12ème Battle Dev. J’ai décroché la 100e place tout pile, et bien que déçu par mon classement je trouve que les problèmes étaient de très bonne qualité, en particulier les deux plus difficiles dont je vais présenter la solution ici.

Read More

IceCTF 2018 writeup - Hot or Not

I’ve been busy recently and couldn’t play CTFs as much as I used to, but IceCTF was such a good memory in 2016 that I really wanted to play their second edition !

Read More