Steganography

Steganography is a means of obscuring a message by hiding it, say within a much larger set of data. Cryptography does not hide a message, but obscures it by manipulating the message, usually with a well known mathematical method. Hidden watermarks in images or documents are a common form of steganography. Always thought there was more opportunity for steganographic methods. Now two scientists, one from Google, have come up with an information-theoretic means to calculate the capacity of channels used for steganography. Technical abstract.