Enhanced the security of image steganography through image encryption

Steganography and Cryptography are two integral parts of information security. Cryptography is the science of using mathematics to encrypt and decrypt data; the data are converted into some other gibberish form, and then the encrypted data are transmitted. Steganography is the art of hidden communications, encoding/embedding hidden information in cover media in such a way so as not to provoke an eavesdropper´s suspicion. If a message is encrypted and hidden with a steganographic method it provides an additional layer of protection and reduces the chance of the hidden message being detected. The primary purpose of this paper is to provide two levels of security through a two step process, rather than hidden the message bits directly in cover image, they are scrambled in a random order generated by 2D Arnold Cat Map after that encrypted message is hidden behind a cover image using basic LSB method. MSE (Mean Square Error) and PSNR (Peak Signal to Noise Ratio) are two common quality measurements to measure the difference between the cover-image and the stego-image. Results showed that the proposed method gives better results than simple LSB with higher PSNR and lower MSE.