Steganography is the art of covered, or hidden, writing. The purpose of steganography is covert communication to hide a message from a third party. This differs from cryptography, the art of secret writing, which is intended to make a message unreadable by a third party but does not hide the very existence of the secret communication. Although the term steganography was only coined at the very end of the fifteenth century, the use of stego dates back several millennia. Steganography hides the covert message but not the fact that two parties are communicating with each other.
