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.
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HKCERT CTF 2022 Postmortem (III): The Remaining Challenges
In the last part, I will include the two non-crypto challenges I wrote for HKCERT CTF 2022: Numbers go brrr and Minecraft geoguessr.
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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.
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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.
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H4CK1NG G00GL3 - Ep 005 Ch 002: Project Zero Adventure
HACKING GOOGLE is a documentary of Google’s cybersecurity teams and H4CK1NG G00GL3 is it’s CTF counterpart. Project Zero Adventure is a cryptography challenge I wrote. In the game, the players control the Security Princess to dodge the obstacles and catch the bugs (a variant of Google Chrome’s dinosaur game). After that, the server will sign messages consisting of the players' name and the score via the `/sign` API. The players will then submit it to the `/highscore` API. If the score submitted to the highscore API is negative, they will be given the flag. However, there is one catch: The server is only willing to sign the results with non-negative scores.
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