Steganography is the ancient art of invisible communication, where the goal is to hide the very fact that you are trying to hide something. It adds another layer of protection after cryptography, because encrypted message looks like gibberish and everyone immediately notices that you want to hide something. Steganography embeds the (encrypted) secret message into an innocuous looking object such that the final communication looks perfectly normal. The “analog” form of steganography is the art of writing with invisible ink. The digital version hides the message by a subtle modification of the cover object. Probably the most researched area in digital steganography uses digital images as a cover media into which the message is inserted. The oldest (and very detectable) technique replaces the least significant bit (of each colour channel) with the communicated message. Shown below, the first picture is the cover object and the second one is the stego object.