Google CTF 2025 Quals Writeup
I wrote two challenges for Google CTF qualifier - Underhanded and Merkurated. There were 17 and 37 solves during the contest time. I will cover both in this blog post.
Read More →HKCERT CTF 2024 Quals Writeup (II): Other Crypto Challenges
In the second part, I will cover the remaining cryptography challenges, including Almost DSA, mAEStro and Mask-mask-RSA.
Read More →HKCERT CTF 2024 Quals Writeup (I): RSA LCG and Pigeon Post
Black Bauhinia co-organizes the HKCERT CTF for the fifth year. I wrote 18 challenges (in 11 series) this year and here is a series of blog posts covering all of them. I will cover two cryptography series in the first part: RSA LCG and Pigeon Post.
Read More →HITCON CTF 2024 Writeup
The crypto challenge authors in HITCON 2024, @maple3142 and @_bronson113 prepared a set of exciting and difficult challenges. I collaborated with @thehackerscrew1 as a guest player this time. In this blog post, we will cover three challenges: ZKPoF, PCBC Revenge and Hyper512.
Read More →TetCTF 2024: adapt
TetCTF comes back with their great crypto challenges. I played with @blackb6a and we ended up securing the 🥉 third place. In this blog post, I will walk through adapt, a challenge which required us to make fake proofs in an IAVL tree implementation. There are only three solves during the contest period.
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