404CTF2023
Ballistic Missile Submarine [964 pts]
Challenge Description:
## ## Challenge Description
We are given a file RadioLondres which is a raw data file, and a hint to use 192kHz.
## ## Solution
For this challenge, I use Audacity to read and analyse the raw file. After having imported the file with the setting Stereo 192000 Hz, 32bit float and switch to spectrogram mode I saw this:
This looks like a morse code to me. We can decode it with Cyberchef:
So the ACCOLADE is the {} and we can see the format of the flag starting with 404CTF.
Let’s submit it: 404CTF{P4UL_V3R14N3_35T_UN_MOR53_?}