STEGANOGRAPHY

Steganography is defined as the art of hidden way of writing whereas the cryptography is the secret way of writing.By using cryptography the third person will know something is crypted.The major advantage of Steganography over cryptography is that it is almost impossible to know that something is hidden.We know that every image is made up of several bits.The data to be hidden is also a series of bits. Steganography replaces the least visible bits in the image by the data bits which is unidentified by the human eyes.The bits to be replaced is generated by an algorithm shared by sender and receiver.The receiver user the same algorithm to generate the bits where his message is hidden.The message is usually compressed and then encrypted before hiding inside a image.As the terrorists extensively use this method for conspiracy the government has involved in extensive research in this field to counteract the terrorists.