2019from public repositories
AffintyCTF 2019
2 challenges with 2 published solutions 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
Breaking Bad
1 official solutionAlso written up in: Logan-47/CTF-scripts
Steganography1
Find the payload hidden inside a carrier that looks ordinary. Bit planes, appended data, metadata, and audio spectrograms.
Solve it with:LSB steganography extractorPNG chunk analyzerAudio spectrogram and SSTV decoderZero-width character and text steganography decoderLearn: Steganography
Script
1 official solutionAlso written up in: Logan-47/CTF-scripts