Information Hiding Systems

The art and science of writing hidden messages in such a way that no one apart from the intended recipient knows of the existence of the message is Steganography. This differs from cryptography, the art of secret writing, which is intended to make a message unreadable by a third party by encrypting the data. If a piece of text looks suspicious , it is easy to suspect that someone wants to hide something for the reader and several decryption methods can be employed to assure an attack .The opportunity to suspect that there is something hidden is not there in case of steganography , thus increasing the level of security by at least one step. The paper is organized into parts; in the first ones an overview and brief technical introduction to steganography is made. However the rest of parts are consecrated for its emphasis on digital applications, focusing on hiding information in image or audio files. KEYWORDSSteganography, Cryptography, Audio-Video streaming, Modulations.