Analysis of Image Encryption using Chaotic, Hybrid Chaotic and Block Cipher Approach

Abstract

Secured image transmission in the network is the biggest threat to the real world because of increasing network security problem, illegal and unauthorized access, malicious code and intruders. The security to the image is given by image encryption techniques. Image encryption is the process of changing the original image into a scramble, unrecognized form. There are various techniques and method for image encryption. In this study chaos based image encryption and block cipher technique are implemented and analyzed for the encryption. Arnold catmap and Arnold catmap with logistic map are used as native chaotic and hybrid chaotic approach respectively whereas AES is used as block cipher approach. The chaotic algorithms encrypt the image by shuffling and scrambling the pixel value of the image which is also called as confusion and diffusion process. The block cipher algorithm encrypt the image by extract the block of 128 bits pixel data from the image with the key of 128 bits. The chaotic and block cipher methods are applied to encrypt image and subjected to measures the different performance parameters like PSNR, NPCR, UACI, Histogram, encryption/ decryption time to measure the strength of the algorithms. The results show the Arnold catmap with logistic map has better NPCR and UACI value which makes it more robust method to defend differential attack or chosen plain text attack it is also computationally efficient since less time is taken for encryption/decryption process. AES has less PSNR value which helps to preserve image properties after decryption and the histogram of original and cipher image more variation in AES than other two approach so it is able to defend statistical attack or cipher text only attacks.