Hide Data In Image Audio & Video Files By Using "Steganography Tools"

What Is Steganography?
Steganography is the practice of hiding private or sensitive information within something that 
appears to be nothing out of the usual.
Steganography is often confused with cryptology because the two are similar in the way that they 
both are used to protect important information.
The difference between the two is that Steganography involves hiding information so it appears 
that no information is hidden at all.
If a person or persons views the object that the information is hidden inside of he or she will have 
no idea that there is any hidden information, therefore the person will not attempt to decrypt the 
information.
Steganography comes from the Greek words Steganós (Covered) and Graptos (Writing).
Steganography in the modern day sense of the word usually refers to information or a file that has 
been concealed inside a digital Picture, Video or Audio file.
What Steganography essentially does is exploit human perception, human senses are not trained 
to look for files that have information hidden inside of them, although there are programs 
available that can do what is called Steganalysis (Detecting use of Steganography.)
The most common use of Steganography is to hide a file inside another file.
When information or a file is hidden inside a carrier file, the data is usually encrypted with a 
passwor




Steganography Terms
Carrier File – A file which has hidden information inside of it.
Steganalysis – The process of detecting hidden information inside of a file.
Stego-Medium – The medium in which the information is hidden.
Redundant Bits – Pieces of information inside a file which can be overwritten or altered with out 
damaging the file.
Payload – The information which is the be concealed




How Does It Work?
There are numerous methods used to hide information inside of Picture, Audio and Video files.
The two most common methods are LSB (Least Significant Byte) and Injection.
I will discuss these two methods below.
Substitution - Altering/Replacing The LSB
When files are created there are usually some bytes in the file that aren't really needed, or at 
least aren't that important.
These areas of the file can be replaced with the information that is to be hidden, with out 
significantly altering the file or damaging it.
This allows a person to hide information in the file and make sure that no human could detect the 
change in the file.
The LSB method works best in Picture files that have a high resolution and use many different 
colors, and with Audio files that have many different sounds and that are of a high bit rate.
The LSB method usually does not increase the file size, but depending on the size of the 
information that is to be hidden inside the file, the file can become noticeably distorted.
Injection
Injection is quite a simple method which simply involves directly injecting the secret information 
into the carrier file.
The main problem with this method is that it can significantly increase the size of the carrier file




Steganography In Images
When hiding information inside images the LSB (Least Significant Byte) method is usually used.
To a computer an image file is simply a file that shows different colors and intensities of light on 
different areas of an image.
The best type of image file to hide information inside of is a 24 Bit BMP (Bitmap) image.
The reason being is this is the largest type of file and it normally is of the highest quality.
When an image is of high quality and resolution it is a lot easier to hide and mask information 
inside of.
Although 24 Bit images are best for hiding information inside of due to their size some people 
may choose to use 8 Bit BMP’s or possibly another image format such as GIF, the reason being 
is that posting of large images on the internet may arouse suspicion.
It is important to remember that if you hide information inside of an image file and that file is 
converted to another image format, it is most likely the hidden information inside will be lost




Steganography In Audio
When hiding information inside Audio files the technique usually used is low bit encoding which is 
some what similar to LSB that is generally used in Images.
The problem with low bit encoding is that it is usually noticeable to the human ear, so it is a rather 
risky method for someone to use if they are trying to mask information inside of an audio file.
Spread Spectrum is another method used to conceal information inside of an audio file.
This method works by adding random noises to the signal the information is conceal inside a 
carrier and spread across the frequency spectrum.
Echo data hiding is yet another method of hiding information inside an audio file.
This method uses the echoes in sound files in order to try and hide information.
By simply adding extra sound to an echo inside an audio file, information can be concealed.
The thing that makes this method of concealing information inside of audio files better than other 
methods is that it can actually improve the sound of the audio inside an audio file




Steganography In Video
When information is hidden inside video the program or person hiding the information will usually 
use the DCT (Discrete Cosine Transform) method.
DCT works by slightly changing the each of the images in the video, only so much though so it’s 
isn’t noticeable by the human eye. To be more precise about how DCT works, DCT alters values 
of certain parts of the images, it usually rounds them up.
For example if part of an image has a value of 6.667 it will round it up to 7.
Steganography in Videos is similar to that of Steganography in Images, apart from information is 
hidden in each frame of video.
When only a small amount of information is hidden inside of video it generally isn’t noticeable at 
all, however the more information that is hidden the more noticeable it will become






Steganography Tool


MP3Stego
MP3Stego will hide information in MP3 files during the compression process. The data is first 
compressed, encrypted and then hidden in the MP3 bit stream.
http://www.petitcolas.net/fabien/software/MP3Stego_1_1_17.zip
JPHide and JPSeek
JPHIDE and JPSEEK are programs which allow you to hide a file in a jpeg visual image. There 
are lots of versions of similar programs available on the internet but JPHIDE and JPSEEK are 
rather special. 
http://www.snapfiles.com/php/download.php?id=101911
BlindSide Cryptographic Tool
BlindSide is an example of the art of Steganography - the passing of secret
messages in a form such that one would not suspect the message is being
passed.  This is an area of cryptography that is attracting considerable
interest of late.  The Blindside utility can hide a file (or files) of any
variety, within a Windows Bitmap image (BMP file).  
http://www.mirrors.wiretapped.net/security/steganography/blindside/
GIFShuffle
The program gifshuffle is used to conceal messages in GIF images by shuffling the colourmap, 
which leaves the image visibly unchanged. gifshuffle works with all GIF images, including those 
with transparency and animation, and in addition provides compression and encryption of the 
concealed message.
http://www.darkside.com.au/gifshuffle/
wbStego
wbStego is a tool that hides any type of file in bitmap images, text files, HTML files or Adobe PDF 
files. The file in which you hide the data is not optically changed. 
http://www.wbailer.com/wbstego
StegoVideo
MSU StegoVideo allows to hide any file in a video sequence. When the program was created, 
different popular codec’s were analyzed and an algorithm was chosen which provides small data 
loss after video compression. You can use MSU StegoVideo as VirtualDub filter or as standalone 
.exe program, independent from VirtualDub.
http://compression.ru/video/stego_video/index_en.html