Steganography – A Scientific approach to Hide Data within data to provide data security

Steganography is derived from the Greek for covered writing and essentially means “to hide in plain sight”. Steganography is the art of inconspicuously hiding data within data. The main goal of steganography is to hide information well. In other words Steganography is the science that involves communicating secret data in an appropriate multimedia carrier, e.g., image, audio, and video files . The aim is to conceal the very existence of the embedded data .In today's world the art of sending & displaying the hidden information especially in public places, has received more attention and faced many challenges. Steganography's ultimate objectives, which are undetectability, robustness (resistance to various image processing methods and compression) and capacity of the hidden data, are the main factors that separate it from related techniques such as watermarking and cryptography. It is well known that encryption provides secure channels for communicating entities. However, due to lack of covertness on these channels, an unauthorized user can easily identify encrypted streams through statistical tests and capture them for further cryptanalysis. In cryptography, the individuals notice the information by seeing the coded information but they will not be able to comprehend the information. However, in steganography, the existence of the information in the sources will not be noticed at all. Most steganography jobs have been carried out on images, video clips ,texts, music and sounds. Therefore, different methods have been proposed so far for hiding information in different cover media. This method can be used for displaying a secret message in public domains which are accessed by any body.