Abstract
The rapid evolution of imaging and communication technologies has transformed images into a widespread data type. Different types of data, such as medical information, official correspondence or governmental and military documents saved and transmitted in the form of images over public networks. Cryptography is a solution to protect confidential images by encrypting before transmission over unsecure channels. Most of the current image encryption methods based on symmetric cryptosystems, which the encryption and the decryption keys are the same and will be shared. However, asymmetric cryptosystems are more useful and secure because of the decryption key kept secret. This paper will focus on asymmetric image encryption algorithms to improve and enhance the security of transmission. Elliptic Curve Cryptography (ECC) is a new public key cryptosystem and provides equivalent security with shorter key length, low mathematical complexity and more computationally efficient rather than RSA. Selective encryption is a solution to decrease the consumed time for asymmetric cryptosystems, which reduce the encryption regions as small as possible. Hence, a hybrid cryptosystem is proposed based on the combination of ECC and chaotic maps that detects the face(s) in an image and encrypt the selected regions. This scheme will encrypt around five percent of the whole image and only confidential regions rather than whole image. The results of security analysis demonstrate the strength of the proposed cryptosystem against statistical, brute force and differential attacks. The evaluated running time for both encryption and decryption processes guarantee that the cryptosystem can work effectively in real-time applications.
Image Encryption and Authentication with Elliptic Curve Cryptography and Multidimensional Chaotic Maps
