Pragyan CTF 2018: Ears to the rescue

Challenge details

Event	Challenge	Category	Points	Solves
Pragyan CTF 2018	Ears to the rescue	Forensic	150	52

Download: audible.wav

Description

Jack is trapped inside a room. All he can see and hear is a sound, his ears hear only the specific sound.

He needs to escape, help him figure out what the sound means.

Methology

Reading the description of the challenge, we are advised that by listening to the soundtrack, we would be likely to help Jack to escape from a room.

As this is an audio stream, let’s use our must-have audio processing tool: Audacity.

From this interesting output, we can quickly identify eight levels of quantization, as follows:

Let’s try to implement this quantization process using Python: decode.py

# python decode.py
The flag is :- pctf{SuRf1n6_th3~4udI0_w4v3s.f0r^lif3}

Here we got the flag!

Final flag:

pctf{SuRf1n6_th3~4udI0_w4v3s.f0r^lif3}

Creased