Steganography is the practice of hiding messages or data within another message or data. In digital steganography this may include code, images, videos or other files.
Steghide is steganography open source software that is able to hide data and has a very powerful command line.
The easiest way to install steghide is to use a package handling utility, for example in Debian-based linux distributions (Ubuntu, Elementary OS, Linux Mint, Deepin, Netrunner, Ubuntu GNOME, BackTrack) you can use:
apt-get install steghide
This is an example of how to use it:
1.First we are going to create a new text file with some text. This would be our secret file – it is just a demo file.
echo “This is my secret file” > secret.txt
2. We are going to use an image (JPEG) to hide this text file, and create a new encrypted file.
steghide embed -cf code.jpg -ef secret.txt -sf code_secret.jpg
embed = embed data -cf = cover file -ef = embed file -sf = output file
3. You can list the encryption algorithms and select one
steghide embed -e rijndael-256 -cf code.jpg -ef secret.txt -sf code_secret.jpg
4. You can also choose the level of compression (1 best speed… 9 best compression)
secret.txt -sf code_secret.jpg