Steganography

Synonyms

Covert communication; Information hiding

Definition

Steganography (from the greek “steganos” – covered) is a term denoting mechanisms for hiding information within a “cover” such that, generally, only an intended recipient will (i) have knowledge of its existence, and (ii) will be able to recover it from within its cover. In modern digital steganography applications, the cover is often a multimedia object such as an image that is minorly altered in the steganographic process. Steganographic techniques have been deployed for millenia and several primitive war-time instances are described in the Histories of Herodotus of Halicarnassus, including a case of a message tattooed on the shaven head of a slave, which, when covered with grown hair acted as an effective “cover” when traversing enemylines.

Key Points

Steganography Versus Watermarking

A common trend of term misuse is associated with steganography. Specifically, many sources consider the term “watermarking” as equivalent....