2019from public repositories
nactf Reversible Sneaky Algorithm 2019
2 challenges with 4 published solutions between them. The writeups for this event were found in public repositories and on the authors’ own sites. Each repository link is pinned to the commit it was read from.
Where these writeups liveUncategorised1
The upstream scoreboard did not say, so neither do we.
Crack
2 official solutionsAlso written up in: NicolaiSoeborg/ctf-writeups, NicolaiSoeborg/ctf-writeups
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
Chals
2 official solutionsAlso written up in: jebidiah-anthony.github.io, jebidiah-anthony.github.io