Image Encryption approach using Chaotic Map for Gray Scale Images

Abstract

With the immense growth of multimedia technology, technologies are required to securely transmit the information over the internet. Conventional algorithms are not good regarding to the safety of image transmitted over the internet and complex to use. So, Image encryption algorithms have been proposed to securely transmit the image over the internet. An exploratory study is performed over various scrambling techniques based on chaotic map. Firstly, image is scrambled with chaotic sequences and flipping such as pixel value is altered using logistic chaotic map while pixel position is altered using flipping. To enhance the security of an image transferred over the internet, another image encryption algorithm is proposed. The image has been divided into blocks and chaotic matrix is generated using Ikeda Map. Each block of image is scrambled by manipulation the column and row shuffling with chaotic matrix. All the scrambled blocks of an image are recombined to get scrambled image. All the pixels of scrambled image are diffused with dynamic index based diffusion. A Comparative study is performed on both the algorithms. During the simulation evaluation, it can be seen that second algorithm provides more security, can resist against attacks and is less correlated than first algorithm.