Steganography is the art of secret writing that dates back to the time of ancient Greece. The goal of steganography is to hide information by embedding it in other messages. Computer graphics such as bitmaps are commonly used. Steganography works by altering the least significant bit of each byte of information. To the viewer of the image, the picture remains the same, but in reality, information has been hidden in it. The hidden information can be plain text, cipher text, or even other images.
Special tools are required to use steganography, and it can be used for legitimate and illegal purposes. Artists might consider using it to watermark or fingerprint their digital art. This would allow them to prove that they are the creator, if the need arose. Hackers, terrorists, and others could also use steganography to move information from one location to another without detection. USA Today reported after 9/11, governmental agencies believed that Al Qaeda operatives had used steganography to hide illicit communications.