Data hiding, a form of steganography, embeds
data into digital media for the purpose of
identification, annotation, and copyright. Several
constraints affect this process: the quantity of
data to be hidden, the need for invariance of these
data under conditions where a “host” signal is
subject to distortions, e.g., lossy compression,
and the degree to which the data must be immune
to interception, modification, or removal by a third
party. We explore both traditional and novel
techniques for addressing the data-hiding process
and evaluate these techniques in light of three
applications: copyright protection, tamper￾proofing, and augmentation data embedding.