With the advances of the digital information revolution and the societal changes they have prompted, it has become critical to facilitate secure management of content usage and delivery across communication networks. Data hiding and digital watermarking are promising new technologies for multimedia information protection and rights management. "Multimedia Data Hiding" addresses the theory, methods, and design of multimedia data hiding and its application to multimedia rights management, information security, and communication. It offers theoretical and practical aspects, and both design and attack problems. Applications discussed include: annotation, tamper detection, copy/access control, fingerprinting, and ownership protection. Countermeasures for attacks on data hiding are discussed, and a chapter assesses attack problems on digital music protection under a unique competitive environment.