Description

Classic crypto
Your mission is to get the hidden message!

Attachment: crypto50.zip

Resolution

Zip contains an audio file which let appear long and short audio, with larger blanks between groups of audio.
So this is a kind of binary encoding.
We may think to morse, and after deciphering morse, we obtain an inintelligible message that we didn’t note.

In addition to a ceasar, we finally find the clear text which was EKOMORSECODECAESAR

Flag was : EKO{EKOMORSECODECAESAR}