Secret Communication through Audio for Defense Applications

Secret Communication through Audio for Defense Applications is MATLAB Project. Main objective of this project is to develop a security related application which is useful for sending secured information encrypting in audio file.

Code Explanation:

Select Wav file (cover signal) for Embedding: 

1. The above set of code would be executed whenever the “Select a .wav file button” is pressed.
2. Next when the “Hide Text button” is selected and the “Select a .wav file button” is pressed then the code would guide us through path and then file name to select the .wav file.
3. As the above sets of steps are executed it would make the “Hide the Text button” go enable.
4. Once the “Hide the Text button” is enabled it reads the selected .wav file and stores first 40 bytes in the variable named “header”.
5. The next 41^st to 44^th bytes are clubbed together to make a single element and is stored in the variable named “data_size”.
6. Then close the file, only wav data samples are sufficient for extracting the text.

Encryption:

1. Enter text in the edit box.
2. Get text message from edit box.
3. Then convert message to binary.
4. Reshape the message binary in a column.
5. Calculate length of message binary.
6. Convert the length to binary.
7. Hide identity in first 8 .wav data samples.
8. Hide binary length of message from 9th to 28th sample
9. Hide the message binary starting from 29th position of wave data samples.
10. Open a new .wav file in write mode
11. Copy the header of original wave file
12. Copy the wav data samples with hidden text in new file
13. Your text is hidden in  new ‘ randname ‘.wav file.

Decryption Process:

. Extract the length of text from first 9th to 28th wav data samples

2. Convert the length to decimal

3. Extract the LSB from wave data sample

4. Convert it to binary

5. Convert to character (ASCII)

6. If message is empty then display File has no hidden text.