Busy weekend with three simultaneous CTFs. I finished 19th over on this one so I feel like I should probably do at least one writeup. This is an unusual category for me, Internet of Things (IOT) which is a lot about firmware reverse engineering usually. Here’s the three challenges I solved Firm1, Firm2, and Firm3 as they’re all related.

An RSA challenge which are always my favourite in CTFs. This one was a combination of a few simple tricks. Below is my solution.

Fourth in line in the Crypto challenge for me was this probably math heavy challenge that I found a secondary solution to. At the heart of it was a bespoke encryption algorithm and an oracle who you can leak the secret from. More details below…

Really Awesome CTF is back in 2021 with some very interesting challenges. This RSFPWS challenge category was particularly fun as it was a 3d game client hacking adventure in 3 parts. I was able to solve all of them and here’s a writeup of the one that had the fewest solvers “Teleport”.

This Web challenge category was oddly misplaced and maybe should have existed within the Reversing category instead but no matter. I class this as a reversing + crypto challenge and I also had a lot of fun solving it as it involves a Golang program which is certainly my favourite language to code in these days.