Cybertalent 2026 NoSQL Writeup

Cybertalent CTF is an annual CTF organized by the Norwegian intelligence service. Had a lot of fun with it this year; my favorite problems were NoSQL and Kaffemaskin. Here’s a writeup of NoSQL. Sorry that there are no screenshots!

JuleCTF 2025 C# Challenges Writeup

JuleCTF is a CTF advent calendar run by the Norwegian national cybersecurity competition (Cyberlandslaget) organizers every December. I believe they started the tradition last year. I wasn’t able to participate then, so I’m happy I got to make some time this year. I managed to solve all the normal problems and 2 out of the 3 bonus problems before Christmas. I really enjoyed it; thanks to the organizers for a fun and varied event!

Understanding OFDMA with Wireshark

The biggest change in Wi-Fi 6 is the introduction of Orthogonal Frequency-Division Multiple Access (OFDMA). OFDMA replaces Orthogonal Frequency Division Multiplexing (OFDM) at the PHY layer and brings support for frequency multiplexing across clients. In other words, a Wi-Fi 6 AP can now transmit to multiple clients simultaneously by using different portions of the bandwidth for each client.