2026from public repositories
CPCTF Very Exciting 2026
1 challenge with 1 published solution between them. The writeups for this event were found in public repositories. Each link is pinned to the commit it was read from.
Where these writeups liveCryptography1
Recover a plaintext or a key from something that was supposed to protect it. In practice: identify the scheme, find the parameter the author got wrong, exploit it.
Solve it with:Cipher identifier and automatic decoderVigenere cipher solver with automatic key recoveryRSA decryption and attack runnerWiener’s attack on small RSA private exponentsIn-browser hash cracker with rule transformsLearn: Classical ciphers and frequency analysisLearn: RSA and the parameters that break it
Server 5dd79bdc6f546c5f0a01a3568e6fe0bbd190887ff16eaf8c34613559c2c574e7
1 official solutionAlso written up in: sajjadium/ctf-archives