Two new approaches for image steganography using cryptography

The process of jumbling up the contents of a secret message so as to secure it, is known as cryptography, whereas the process of hiding the very existence of a secret message is known as steganography. The term “steganography” describes the method by which the contents of a secret message are concealed inside some other medium, so as to avoid any kind of detection by an intruder. In this paper, we have proposed two new approaches wherein both cryptography and steganography are used to encrypt the data and also to conceal these encrypted contents in some other medium. In the first method proposed, we have secured an image by converting it into an encrypted text using S-DES algorithm and a secret key and then concealing this encrypted text in some other image, whereas in the second method, we have secured an image directly by encrypting it using S-DES algorithm and an image key. The contents thus obtained are concealed inside another image so as to hide its very existence. Both these techniques have been tested and it has been observed that they prevent the possibilities of steganalysis also.