2019from public repositories
Utcteaser 2019
2 challenges with 2 published solutions between them. CTFtime has no listing for this event at all, so nothing built on CTFtime can show what it was made of. These writeups were found in public repositories instead. 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
Curve It Up
1 official solution
Misc1
Everything that fits no other box: esolangs, puzzles, scripting exercises, and the jail escapes that have not yet earned their own category.
Solve it with:Brainfuck and esolang decoderCipher identifier and automatic decoderRegex tester with match offsets and capture groupsLearn: Recognising encodings
Really Good Bicture
1 official solution