According to the Wikipedia, Steganography is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message, a form of security through obscurity. Let’s explain this with examples. If you send a normal message contains secret data that no one will know how to extract this data but the receiver, this will be considered Steganography. But things are more complicated now because of computers and digital technology. One of the most widely used techniques in digital Steganography is the Lest Significant Bit (LSB).
A lot of people are aware of hiding data inside images, MP3 files, and even spam emails! But technology increased the value of Steganography as a safe and secure method to conduct a criminal act. Cyber terrorists my use this as a method of sending information about the attacks and their targets to other terrorists. Although there are no evidences that terrorists or even “Jihadists” are using Steganography, one of the well-known manual for “Jihadists” is talking about the techniques of covert channels. It will be easier for terrorists for sure to use Steganography instead of encryption. If you encrypted a message, it will be suspicious for anyone. He will think for sure that this message contains sensitive if not secret data! Additional advantage of Steganography is that it can’t be traced!
Steganography usage is on the rise. It is not used only by hackers, cybercriminals, and terrorists but it is widely used in digital and commercial espionage. I remember one of the stories about an MP3 file sent over peer-sharing network to one of the employees in a Korean company. The MP3 file contained prototype for mobile phone which later used to develop an identical copy of the original one!!!
I believe that Steganography techniques will continue to progress and will be used widely in “Information Smuggling” even at governmental levels!
If you want to learn more about Steganography, please download my presentation.
Additional important information:
VoIP Steganography on IEEE Spectrum