Tereno de Argilo
Lemondronor
About Posts Oct 4, 2022 Building challenges for the GRCon22 CTF Since 2016, the GNU Radio Conference has held a Capture the Flag (CTF) competition in parallel with its technical track. Secret messages (“flags”) are hidden in radio signals, which players have to find and then submit to a scoring system to earn points. The CTF is my favourite part of GRCon, so when the conference organizers asked whether I’d be willing to organize this year’s competition, I jumped at the opportunity. Luckily, I didn’t have to
The event was a phenomenal success. There were 52 challenges, and 71 teams submitted 686 valid flags. Even though the competition period has ended, most of the challenges are still up and playable at https://ctf-2022.gnuradio.org/ .
In this post, I’ll describe how I created my challenges, and how I anticipated they might be solved. If you don’t want any spoilers, stop reading here!
Tereno de Argilo
Lemondronor