Chaotic Image Encryption Based on Modified Logistic Map

Abstract

Security of image is one of the vital aspects in the big and still growing world of image encryption as a bulk of data is being transferred over the internet that includes text, audio, videos, images, and various other kinds. Images are now largely used in and are a part of daily life in various aspects, therefore security of image is a very important. Encryption of images is the best way to protect confidentiality of images over a public media. Also, it is an approach to guarantee that images with high security are incorporated in numerous fields, for example, medical science, military etc. This medium is prone to attacks and subsequently efficient encryption mechanisms are need for secure communication. Cryptography provides the capability of protecting the confidential information from unauthorized and unknown access. It’s vital to transmit reliable data. Present day cryptography gives basic mechanisms to verify and protect information. Until now, encryption methodology has been growing rapidly and a large number of  encryption strategies have been utilized to preserve confidential data image from unknown attacks or unauthorized users or access. In this paper, an overview of various image encryption methods which are based on chaos has been examined and and the problem of limited chaotic range of logistic map is found out. This problem of small chaotic range is solved in this paper by modifying the basic logistic map to bring out a wider range and use the keys from this range to encrypt image. Three modifications of logistic map is introduced in which the keys from first two modifications are merged together and xored with the plain image to form primary cipher and this result is transposed with third key from third modification done to bring out the final cipher image.