Data hiding is the art and science of communicating secret data in an appropriate multimedia carrier, e.g., image, audio, and video files. Reversible data hiding restores the carrier after the removal of hidden secret data. Data Hiding is referred to as a process to hide data (representing some information) into cover media. That is, the data hiding process links two sets of data, a set of the embedded data and another set of the cover media data. The relationship between these two sets of data characterizes different applications. For instance, in covert communications, the hidden data may often be irrelevant to the cover media. In authentication, however, the embedded data are closely related to the cover media. In these two types of applications, invisibility of hidden data is an important requirement.