Steganography is the art and science of hiding messages, Images, Data etc. in such a way that no one, apart from the sender and intended recipient, suspects the existence of the Data- security through obscurity. By using this small and neat trick you can hide whatever data you want behind any image of your choice without reducing its quality, In the following tutorial I will show you how you can hide data behind images without using any exotic software.(Good old Winrar or Winzip is sufficient)
1. Create a folder in your C drive and name it as "hide"(Using Root Directory will make this a bit easier).
2.Now you can put anything and everything you want to hide in this folder. Text files,images,executables (ANYTHING).Also, put the image behind which you want to hide the files in the same directory, say "image.jpg".
3.After putting everything you want to hide in the "hide" folder, Right click on it, and click "Add to Hide.rar" or "Add to archive". Our goal is to create a .rar file of the "Hide" folder.
Now you should see the "hide.rar"created in the same directory along with the folder.
4. Now we need to open up command prompt and change the working root directory to your current directory and type the following commands.(First change directory then create the output file).(Remember "C" is capital in "C:\\")
►Copy /b image.jpg + hide.rar output.jpg
Here "image.jpg" is the image behind which you want to hide the rar file.
"hide.rar" is the file containing the files to be hidden.
"output.jpg" is the output file that we want. It contains the hidden files, but looks like an image
After executing the following command, we will see an extra image called "output.jpg" created in the same directory.(Note that it's size is size of image.jpg +size of hide.rar)
Now you can delete all the files except "output.jpg". If you double click the file, it opens a normal image. But you can see the hidden files by opening the file with winrar.(Right Click->Open With->Choose WinRar.)
That's It! Now you can send this image to anyone, what others will see is just a regular image but if the recipient knows, s/he will be able to access any secret information privately.This tutorial can be used for any type of files like mp3,wmv,txt etc. since anything can be put into a Rar file.
Although you may want to keep the files to be hidden as small as possible since it wouldn't be very subtle if you try hiding a 15 Gb setup file for the game 'Crysis 3' behind a 5Kb smiley picture.