An Image Encryption Method by Sub-image Shuffling, Bit-level Permutation and Diffusion using Chaotic Maps

Transmission of images securely through a channel can be ensured using cryptography techniques. Encrypting an image with the help chaotic maps provides security and authentication. This paper presents encryption method which consists three main steps: Sub-image shuffling, bit-level permutation, diffusion. The sub-image shuffling step is performed logistic map to increase robustness proposed method. In permutation process, highest four bits each pixel are obtained. row column transformations applied sequences generated by tent map. Finally, in diffusion step, values image’s pixels altered. Two different obtained from employed. Five parameters selected as secret keys for encryption. performance suggested tested several analysis methods. Key space shows that withstand brute force attacks. It also proven highly sensitive keys. Histogram illustrates fact encrypted uniformly distributed. Also, correlation between neighboring reduced compared plain image. differential demonstrates slight changes even though same used.