When you need to send confidential documents to someone, the steganography can be an effective technique. Hide them in a file that no one will think of analyzing: an mp3.
Then just email them as usual, and prying eyes will only see normal pictures. They will never realize that your hidden data is inside.
What is steganography?
La steganography is a computer technique that allows information to be concealed. The principle is both very simple and very ingenious. It consists of hiding confidential data within various and unsuspected elements.
Transposed into the computer world, steganography can take several forms. For example, a secret message can be included in an image, text or audio file.
Who would fetch bank transaction information from a kitten image or Ariana Grande's latest headline?
Hide data in audio files with DeepSound
Several Steganography tools exist. However, here we are going to use DeeepSound which allows hiding data within an audio file.
DeepSound is a free tool which gives you the ability to hide any kind of data, from text to photos, inside audio files and best of all, everything can be encrypted with AES256 bit.
1) Download and install DeepSound
To start, go to the DeepSound website and download the software.
Once the installation is complete, you should be greeted with a screen like the one below.
The interface of DeepSound turns out to be rather simple. On the top side of the screen, it displays the directory structure of your local drive.
2) Select the audio files
At this step we need to select audio files in which to hide the data. To do this, click on the button Open carrier files. Select the audio file that will be used to hide the data.
3) Add the secret document
Now you have to choose the document you want to hide. To do this, click on the button Add secret files.
Select the file containing the sensitive information you want to hide in the audio file. This is a Word document in our example. You can add multiple documents to the audio file.
4) Encrypt hidden file
Finally, click the button Encode to add a layer of security by encrypting the hidden document.
In the window that appears, check the box Encrypt secret files (AES 256). Enter a password and confirm it. Validate with a click on Encode secret files.
Your document is now encrypted and hidden with your audio file! Not only does this file look like a normal audio file, but if someone wants the information to be hidden there, they will have to decrypt it with the password known only to you.
5) Access the hidden document
The audio file with the secret document is immediately created and saved in the Documents folder. It can be read normally by any audio player. To access the hidden file, you will need the DeepSound application.
Drop the file in the section Carrier audio files. When you do, it will ask for a password. Enter the password you created in step 4, press "OK".
Finally, click Extract secret files and the hidden file will appear in the right window.
Now you can read the hidden document using the appropriate software.