Last year, I created a pwn challenge for the Bauhinia CTF competition. Personally, I consider it to be the most difficult pwn challenge I have ever created, and here I would like to share the challenge and its intended solution. At the same time, I will discuss common solving approaches you may find useful for this type of challenge. Overview As a CTFer, we have the obligation to code any program in a secure manner, even if a university assignment, right?...
Welcome!! (23 points, 663 solves) Difficulty: Warm-up We surely did get warmed up this CTF, as we came second, even beating the Cryptohackers (merge) team! Well done to everyone who participated 馃挏 Did it! (33 points, 220 solves) Difficulty: Easy The parameters $n = 127$ and $\ell = 20$ is fixed. A hidden subset of $\ell$ numbers $S \subseteq \{0, 1, \cdots, n - 1\}$ with $|S| \leq \ell$ is chosen, and we are given $13$ calls to the following oracle: Given a set $T \subseteq {0, 1, \cdots, n - 1}$ also with $|T| \leq \ell$, the server computes $T \setminus S$ and outputs $\{(u^2 + \varepsilon) \pmod{n} : u \in T \setminus S, \varepsilon \in \{0, 1\}\}$....
One challenge we wrote for HKCERT CTF 2022 is Minecraft Geoguessr. In this blog post, we will talk about stuffs behind the scene, including how the challenge was created and the lessons learnt. If you are interested in the solution, please refer to @mystiz鈥檚 blog....
Our collection of writeups for LA CTF 2023....
Our collection of writeups for idekCTF 2022*....
Our collection of writeups for ASIS CTF 2022....
I did not solve it in time (30 minutes late T.T). However, I spent quite of lot of time on this challenge, so I might as well do a write up. Special thanks to Mystiz, fsharp, cire meat pop for helping me on this challenge....
We played BackdoorCTF and we won the second place....
We played BSides Mumbai CTF 2022 last week and we got the third. This is the write-up on the challenges we solved....
We played TSJ CTF last weekend and we won! This is the writeups of our challenges...