Chaotic Systems in Cryptography: An Overview of Feature-Based Methods

Abstract

The increasing growth of Information and Communication Technology has influenced rapid changes in the method of data transmission and storage, especially through the Internet. These rapid exchanges and storage of large volumes of data have also brought in newer and unexpected challenges concerning security. Consequently, the protection of sensitive information against unauthorized access has emerged as a major concern for sectors such as finance, healthcare, government, and personal data management. With time, cryptographic techniques have emerged as the cardinal solutions that can keep data safe from breaches or cyber-attacks. Cryptography offers various techniques in encoding data to prevent unauthorized access to data and protect confidentiality, integrity, and authenticity. Chaotic encryption systems are one of the innovative approaches to cryptography to which much attention has been turned by the research community over time. Chaotic encryption systems are based on the principles of chaos theory and exhibit important features that include high sensitivity to initial conditions, unpredictable behavior, and complex dynamics. These properties are particularly helpful in encryption, as they allow for complex transforms of information, were, without the proper keys, it would be highly impossible for unauthorized entities to decipher encrypted content. Chaotic encryption has especially shown promising applications in image encryption, where traditional cryptography methods often cannot work properly due to the large data size and structure of the visual information. The principle of image encryption using chaotic maps then consists in using mathematical functions with inherent features of randomness and sensitivity, which introduce extreme complexity into the encryption images, resulting in a visually unrecognizable and resistant characteristic to cryptanalysis. Some chaotic systems such as the Logistic Map, Lorenz System, and Henon Map have been used to securely encrypt an image by scrambling its pixels and changing their intensities according to initial chaotic conditions. This paper reviews the efficacy and potential of chaotic encryption systems in enhancing the security of data, and more importantly, image data, through reviewing some basic principles of chaos theory, benefits, and limitations of different chaotic maps, and discussing some recent chaotic encryption methods.