Vol. 3, Issue 7, Part R (2017)

Abstract
Cryptography is a study of secure communication over insecure channel. It deals with hiding information in secret codes to make sure that anyone but the intended recipient can’t access it. The encryption algorithm is needed to be large to provide high security and to withstand the brute force and statistical attack. The traditional methods like DES, AES are not suitable for image application due to relatively small block size, the nature of digital image, bulky data capacity and high correlation among the pixels. The proposed method uses a combination of transposition and substitution using chaotic theory and feedback register, along with a key factor to encrypt the secret data bits, before transmission, to enhance the security of the image.