An overview of encryption algorithms in color images

Nowadays, security in data transfer is of special importance. Images are of the most attractive kinds of data in the encryption domain. Color images are more attractive than the gray-level images due to provision of more information. In the present study, various existing color (RGB mode) image encryption schemes have been examined comprehensively based on the application domains in addition to summarizing over 50 studies in this field, most of which being published in the last year. In addition, in this study, color image encryption has been categorized into ten schemes, then the proposed schemes have been compared and their advantages and limitations have been highlighted. Moreover, a complete list of common security analysis techniques for (gray or color) image encryption has been discussed which are capable of evaluating the method potential resistance to different possible attacks. The present study has been carried out to provide detailed knowledge regarding the existing image encryption schemes in the area of the RGB images. Finally, in the current study, various open issues and research directions have been considered in order to explore the promising areas for future developments. (C) 2019 Elsevier B.V. All rights reserved.