Task 2

The second task consists of analyzing a group of suspicious audio files (Ex3_sound2.wav, Ex3_sound3.wav, and Ex3_sound4.wav), determining which one contains a four-number secret code. In this case, the spy has used a more sophisticated method. It seems he has used amplitude modulation to ‘move’ the secret code to an ultrasonic range of frequencies and then mixed this code
with that of the suspicious audio files.

To solve this task, you must create an application in Python (exercise 3.2) that should detect which one of the audio files seems to contain suspicious data in an ultrasonic range of frequencies and should be able to play the secret code in an audible range of frequencies.

Task 3

The third task consists of creating a more sophisticated algorithm for embedding hidden messages based on the LSB audio steganography method (exercise 3.3). You will create an application in Python and use the audio file Ex3_sound5.wav to embed the secret message ‘Father Christmas does
not exist’. The application must include an algorithm that performs the opposite operation (i.e. an algorithm able to extract the hidden message embedded in Ex3_sound5.wav).

You could, for example, to distribute the hidden message through non-consecutive audio samples using a random pattern, use more than one least significant bits to hide the secret data, etc