[noxCTF] Sublime

Challenge by G4S

Sublime is a medium difficulty cryptography challenge about the substitution cipher. I made this challenge more difficult by setting the substitution range of values to the whole ASCII table. To solve this challenge, you first need to perform a frequency analysis on the given ciphertext, omitting the variety of punctuation marks from the analysis but spaces (e.g. dots, exclamation marks, question marks etc..) and sort the frequencies from the highest to the lowest. [Read More]

[MagTF] Crypto1sFun

Challenge by WelloWorld

So, this is a medium-hard crypto challenge with a little bit of forensic. The solver gets a server and port and a description says: “Today you will learn to work with two important mechanisms: The first one is very known today as a good mechanism, and the second one is old and not used today as normal mechanism.” The mechanisms are: Deffie-Hellman key exchange and the WEP for wifi authentication (wifi is not really here). [Read More]