The aim of this project is to use the python thinkdsp library to breakdown and decipher an encoded audio file, there are 3 exercises each with varying levels of complexity.
- A encoded Audio file will be provided and the goal is to retrieve the hidden message buried at each complex layer
Excercise 3.1 - Hidden text msg among audio file
A hidden text message is buried among the audio file, and a decoy music is used to mask the original message. Here are the steps to retieve the message:
- Convert the audio file into a byte array
- Use
LSBmethod and get the lowest bit of the audio frame - Convert the extracted bytes into a string text
A secret audio message is recorded at a lower frequency than humans are able to hear. The message is also split across 3 audio files sound2.wav, sound3.wav and sound4.wav for added secrecy.
The method in solving this is quite straight forward:
- First combine the 3 audio files into one single file, lets call it
sound5.wavand read from that - The file will under go a high-pass filter to remove all sounds above a certain freq
- Then i will use demodulation to tune the sound into something recognizable
Now I have to use the method I have learnt above and encode my own secert message using the techniques as an example.