I have participated in several capture-the-flag competitions over the years as a member of STT
I usually focus on solving cryptography challenges. Here are some of my writeups:

• Clutch - HTB
• Clement - ASIS CTF
• Fake Medallion - Plaid CTF
• YAFM - Google CTF

I have implemented some tools to help solve challenges:

• Symbolic Mersenne Cracker - A tool that models the mersenne twister function as a Z3 program and is able to predict the next bits coming out of Python's RNG given just a few bits

I was one of the team captains of Team Europe, and won ICC. Now I get invited to create cryptography challenges for the new candidates, since I am too old to participate as a player 😢.
Over the years I won multiple awards (usually in teams) in several different CTF competitions, including:

• Led team Europe in ICC 2022 (1st place)
• Led team Portugal in ECSC (7th place)
• CSAW Quals 2020 (5th place)
• CSAW 2019 (2nd place)
• CSAW 2018 (3rd place)

To name a few. Anyways, yeah I like to play CTFs a lot