In the second part of the series, I will cover four cryptography challenges: baDES, Maybe Someday, Cipher Bridging Service and RSA Triooo. Interestingly, most of them are somehow “plagiarized” from the other CTFs.

This is yet another moment that Black Bauhinia co-organizes HKCERT CTF. This year, I am slightly more productive than the previous years and wrote 13 challenges for the CTF. There are three blog posts in this series, where I will respectively cover the author’s solutions to the easier crypto challenges, the harder crypto challenges and the remaining challenges.

This is yet another annual Firebird CTF and I only wrote one cryptography challenge this time, Goldilocks. There were one solve (out of 53 participating teams) during the contest period.

There are a lot of ups and downs for in 2023. There were some joyful gatherings and reunions, but at the same time, things did go very wrong.

The crypto challenges in DownUnderCTF are very intriguing. Unfortunately I have very limited time during the contest and could only solve apbq rsa ii (26 solves), hhhhh (14 solves) and handshake (4 solves). I will be covering the latter two challenges in this writeup.