A modified (Dual) fusion technique for image encryption using SHA-256 hash and multiple chaotic maps

A Modified Dual Fusion (MDF) technique of image encryption is proposed in this paper to overcome the limitations that exist in the original research work of Q. Zhang et al. (Optik 124: 3596-3600, 2013). A novel technique of DNA encoding is applied through chaotic maps on pixel level and SHA-256 hash of the plain image is used to generate secret keys to avoid chosen-plaintext attack. Also, in the modified scheme, two random images are generated from chaotic maps to fuse with the plain image after permutation in digital and DNA domains using XOR and addition operations respectively. The simulated experimental results and security analysis show that the proposed cryptosystem has fairly good encryption effect than the original fusion scheme but also has the capability to sustain noise which gets add during transmission over noisy channel. Besides, the paramount factor of improved scheme is suitable for the real time applications.