SECURED CHAOTIC MAP TECHNIQUE FOR DIGITAL IMAGES

Abstract

The onset of the pandemic made companies go digital; this led to massive data transfer hence the need for highly secure and fast data encryption techniques. Most real-time applications in mobile communication, military, and private organizations often require safe and reliable data monitoring and transfer. As one of the most crucial areas of information security, chaos based image encryption has attracted academics and scientists over the past few years. Several studies with different approaches and new algorithms to make image encryption systems safer were proposed in recent studies. Traditional encryption techniques are challenging to understand, complex to implement, slow for encryption, and unsuitable for real-time and multimedia applications. Hence many researchers used chaos-based cryptography. Chaotic-based cryptosystems take full advantage of chaotic dynamics, diffusion, and confusion performances to achieve adequate security. In diffusion, ciphertext and plaintext form a complex relationship, while confusion emphasizes how sensitive the ciphertext is to the plaintext. A small change in the plaintext will significantly impact the ciphertext. However, the main problem with most chaos-based algorithms is the inadequacy of the chaotic maps they implement. Hence, most researchers used more than one chaotic map or a higher dimensional chaotic map in the system. We seek to develop new, secure, reliable, Symmetric, and asymmetric cryptosystems based on chaos theory. We aim to incorporate chaotic dynamics into cryptography to create new asymmetric and symmetric algorithms using the lower dimensional chaotic map. The main work can be summarized as follows: i. We design and test a robust, efficient symmetric key stream cipher based on chaos theory. The key was generated using based on a 3-dimensional Logistic Map. The proposed techniques use a secure logistic map with XOR operators and shift operations to perform encryption. The tests we iv conducted determined that the proposed scheme is cryptographically sound and meets the needs of different analyses. ii. The chaotic maps used in chaos-based cryptosystems in digital devices show dynamical degradation with finite precision. Considering that chaotic maps are based on real numbers, this has the disadvantage of high computation costs and inefficient resource use. Hence, we used both the real and imaginary parts of one superior logistic map for key generation. An image is scrambled and diffused by combining a chaotic sequence with a secret key entered by the user. The image is then evaluated using various measures such as NPCR, UACI, MSE, PSNR, and entropy. iii. Based on the chaotic Tent map, we propose a secure and robust system for the implementation of asymmetric key cryptosystems using chaos based techniques. For the construction of public and private keys, a salp swarm optimization algorithm was used, along with a chaotic one dimensional tent map, . In order to ensure good cryptography, the key space must be large, so that brute-force attacks cannot be performed against it, the secret key must be highly sensitive, and pseudo randomness should be employed in order to hide the correlation between the key, the plaintext, and the ciphertext. It has been demonstrated through security analyses and experiment results that the proposed chaos-based cryptosystem is complex and provide confusion and diffusion.