Encryption, data hiding and watermarking

Terrorists might use it to mask their messages: it's called data hiding - the subject of a new book by Ali Akansu, PhD, professor of electrical and computer engineering at New Jersey Institute of Technology (NJIT).
Akansu's book, Data Hiding Fundamentals and Applications: Content Security in Digital Multimedia, (Elsevier-Academic Press 2004), develops a theoretical framework for data hiding techniques, including watermarking. Encryption and data hiding are two technologies that play major roles in information security and assurance, Akansu says. A key issue in content-security solutions is the imperceptible insertion of content and information into multimedia data.