Google CTF 2023: MHK2
MHK2 is one of the challenges I coauthored for Google CTF 2023 and there were 18 teams solving this challenge during the contest time.
Read More →idekCTF 2022* Writeup
idekCTF 2022* definitely has a fun and inspiring set of cryptography challenges. I played with @blackb6a and we solved 8 of the 10 crypto challenges. In this blog post, I'll include my solution on three of them: Primonumerophobia (10 solves), Chronophobia (5 solves) and Decidophobia (3 solves).
Read More →
Firebird Internal CTF 2023 Writeup
Like in 2021 and 2022, I contributed some challenges for Firebird’s internal CTF, which are from the Hong Kong University of Science and Technology. This time I wrote three crypto challenges: Randomsum, Shelter and Threerider. There were 24 teams participating. There were three solves for Randomsum, while Shelter and Threerider were unsolved during the CTF.
Read More →
HKCERT CTF 2022 Postmortem (II): Harder Crypto Challenges
We will continue walking through the remaining crypto challenges I wrote for HKCERT CTF 2022: Mystiz can't code, Slow keystream and King of Rock, Paper, Scissors.
Read More →
HKCERT CTF 2022 Postmortem (I): Easier Crypto Challenges
This is the third year Black Bauhinia co-organized HKCERT CTF. This time I wrote nine challenges: Seven crypto, one reverse and one misc. Similar to the last year, I have a series of three blog posts walking through the challenges that I wrote. We will discuss the four easier crypto challenges: Flawed ElGamal, Catch-22, Rogue Secret Assistant and Base64 encryption.
Read More →