A novel dynamic chaotic image encryption using butterfly network topology based diffusion and decision based permutation

Many techniques like encryption, steganography, watermarking are used for sending multimedia information securely over the internet. This paper focuses on encryption technique for secure transmission of images. For this, a Secure Dynamic Decision based Permutation and Butterfly Network Topology (BNT) based Diffusion (SD2PBD) model is proposed for images. Two different models are enforced for creating initial vectors of Henon map which in turn used to generate the random key sequence for every encryption to achieve high plain image sensitivity. For confusing the pixels, a simple chaotic and decision based four-way Zig-zag scan is employed and after performing this three level diffusion with BNT architecture is proposed. The BNT architecture has internal bit-wise permutation. It is an additional advantage of this encryption scheme with less computation time. Simulations are done with different type of quantitative measurements in order to analyze the effectiveness of the present technique with respect to different types of attacks. From the NPCR and UACI analysis, the proposed scheme is proved to be secure against differential attacks.