A Comprehensive Review of Key-Based Image Encryption Techniques: From Classical Ciphers to Intelligent Key Generation

Due to the rapid increase in sharing of digital images over communication networks, confidentiality and integrity have become a major research concern. Image encryption system relies largely on the design and variety of encryption keys in order to achieve its strength. The present paper provides an extensive literature review of a wide range of key-generation schemes, including the static and pseudo-random ones, those based on chaos, DNA-coded and AI-based schemes. This paper critically examines more than 20 years of research and discovers the current areas of strengths, weaknesses, and gaps in the research on key-based image encryption. In addition, it suggests a classification scheme and brings into focus new tendencies like intelligent, adaptive and hybrid key generation to multimedia security next generation.