steganography
The art and science of concealing a secret message, data, or file within another innocuous message, image, audio file, or physical object in a way that hides the very existence of the hidden information from casual observation.
uncountable
She shewed me a short manuscript in French, where the great work was clearly explained. She told me that she did not keep it under lock and key, because it was written in a cypher, the secret of which was known only to herself. "You do not believe, then, in steganography."
The use of small computer files to communicate secret information.
uncountable
Using the steganography tools available today, suspects can even hide data inside JPEGs and audio files.
Where it comes from
From Ancient Greek στεγανός (steganós, “cover, roof”) + -graphy.
Adapted from the Wiktionary entry steganography (CC BY-SA 4.0).