- In this challenge we are given an audio file.
- We are also given some some texts about audio file but i didnt understood even a single word of that.
- At first i was searching for morse code then i took hint for 20 points and then i realised there is binary.
- Open the audio file in sonic visualiser.
- Under the pane option in menu select melodic range spectogram.
- There you will see some blocks coloured and some not coloured.
- The coloured block represents 1 and non coloured block represents 0.
- After extracting the binary it looks like this.
10101010001001000010000110100111101001110011110110100111101001110001100110101111100111000001100010101010001111101
- It contains 113 bits and we know that 1st word will be T because it starts with 'THCON' and binary of T is 01010100 so maybe 1st digit 1 is extra byte after removing it it looks like this:
0101010001001000010000110100111101001110011110110100111101001110001100110101111100111000001100010101010001111101
- After converting the binary to ascii the flag is obtained.
THCON{ON3_81T}