Abstract
For the purpose of representing complex data, images are the most convenient and effective way. In these days, huge amount of images are often moved from one location to another location of world with the application of internet. Moreover, as it’s common that the Internet more sensitive for the wide range of issues for security. In form of consequences, such images may become victim of content manipulation, unauthorized access, content destruction, privacy leakage, etc. To troubleshoot these issues, our system must have capability to encrypt the image before transmitting it over the Internet. In order to fix these issues, so many encryption approaches has been proposed by expert from all over the world. Most of these encryption approaches are worked either in spatial or frequency domain, but mostly only suitable with gray scale images. The main aim of this paper is to propose an image encryption approach that is to be done into spatial domain along with frequencies domain, but effective for color images as well as gray scale images. In encryption process of proposed work, the color images are first confused in frequency domain using the Discrete Cosine Transformation (DCT) and Arnold Cat Map. In second step, the confused image’s frequencies are converted into spatial domain using the Inverse Discrete Cosine Transformation (IDCT), and defused the image’s pixel using the Logistic Map followed by the Henon Map. At the end, we get the resulted encrypted image. At last, various tests will be performed and there result’s has been analyzed to prove the strength and effectiveness of the proposed approach of encryption. The experimental result of proposed work has also been compared with the existing encryption techniques. The result of various test claim the effectiveness of the proposed work.
Keywords: Encryption, Decryption, Diffusion, Confusion, Chaotic Map, Discrete Cosine Transformation, Key-Sensitivity.