An Analytical Survey of Image Encryption Techniques Used in Various Application Domains

Due to continuous innovations in machinery, digital images are extensively used in numerous domains like remote sensing, military, communication, medical, etc. These images may encompass subtle and private data. Thus, images are mandatory to be secured from illegal access. Several image security methodologies have been developed in previous years. Most of the techniques to secure the images use encryption. In this method, an encrypted image is generated from the plane image using an encryption algorithm and a secret key. Researchers are continuously devising new techniques in various domains for image encryption. To increase image security, various researchers have devised new techniques for image encryption. In this perspective, an analytical survey of the current image encryption approaches is presented in this paper. The investigation covers the application of encryption techniques in various application domains such as finance, defense, remote sensing, medical, etc. The image encryption techniques reviewed in this paper are categorized based on chaotic map, DNA coding, neural network, and spatial techniques. These techniques are compared to assess those on the basis of various security parameters. In addition, the performance of these techniques is also analyzed. The future directions to encourage researchers for devising new encryption techniques are also presented in this paper.