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

• Fake Medallion
• YAFM

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. I was also recently invited to create cryptography challenges for the new candidates.
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 play a lot of CTFs