2023from the authors’ own sites
DuckCTF 2023
7 challenges with 7 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 on the authors’ own sites instead.
Where these writeups liveUncategorised6
The upstream scoreboard did not say, so neither do we.
Easy Overflow
1 official solutionHomebrewed Block Cipher
1 official solutionMagic Beans
1 official solutionNot So Standard Substitution Cipher
1 official solutionReturn Address Override
1 official solutionThe Lost Book
1 official solution
Cryptography1
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
A Based Crypto
1 official solution