How to Hide Secret Data in image and audio files Ubuntu / Debian: Steghide

steganography is the technique used for hiding various data in different type of image and audio files with out changing the basic characteristics of file. Steghide is a utility for steganography. The color- respectivly sample-frequencies are not changed thus making the embedding resistant against first-order statistical tests.

Features include:
* Compression of embedded data
* Encryption of embedded data
* Embedding of a checksum to verify the integrity of the extraced data
* Support for JPEG, BMP, WAV and AU files

How to install steghide in Ubuntu / Debian
Open a terminal
$apt-get install steghide (or Use Synaptic Package Manager)

Basic Usage
$ steghide embed -cf picture.jpg -ef love.txt
  Enter passphrase:

  Re-Enter passphrase:

  embedding "love.txt" in "picture.jpg"... done

This command will embed the file love.txt in the cover file picture.jpg

After you have embedded your love letter love.txt data as shown above  and you can send the file picture.jpg to your lover.

Now How to extract file

$  steghide extract -sf picture.jpg
Enter passphrase:
the file "love.txt" does already exist. overwrite ? (y/n) y
wrote extracted data to "love.txt".

This will give file information

steghide info picture.jpg
"picture.jpg":
  format: jpeg
  capacity: 1.2 KB
Try to get information about embedded data ? (y/n) y
Enter passphrase:
  embedded file "love.txt":
    size: 34.0 Byte
    encrypted: rijndael-128, cbc
    compressed: yes