âSteganography is the practice of concealing a message within another message or a physical object. In computing, (electronic contexts) a computer file, message, image, or video is concealed within another file, message, image, or video. The word âsteganographyâ comes from Greek âsteganographiaâ which combines the words âsteganosâ meaning covered or concealed and â-graphiaâ meaning writing.â
âHolography is a technique that enables a wavefront to be recorded and later reconstructed It is best known as a method of generating three dimensional images and has a wide range of other uses including data storage microscopy and interferometry. In principle it is possible to make a hologram for any type of waveâ