A New Color Image Encryption Algorithm Using Random Number Generation and Linear Functions

Abstract

In this paper, we introduce a new method of color image encryption. The principle of this approach is to encrypt any color image (called the original image), into a sequence of N images whose (N − 1) of them are generated randomly, and the Nth image is calculated from the original image and the (N − 1) generated images using a linear equation. This process will be repeated for each color image channel (red, green, and blue). Those (N − 1) generated images are used as a symmetric key in the decryption phase; therefore, they should be shared with the receiver privately or via a secure channel. Only the Nth image will be sent. To obtain the original image, we need all N images in the decryption phase. Our encryption system can resist brute-force attacks as well as statistical attacks. The results are justified by applying several safety criteria, such as correlation coefficient and histogram.