Abstract
In many encryption systems, the original data are transformed into encrypted version by applying nonlinear substitutions and inducing diffusion. The objective of the nonlinear transformation is to attain high levels of randomness in the cipher text. The choice of the source of randomness is critical because the success in cryptanalysis is demarked by the characteristics identified in the encrypted data. The chaotic systems show random behavior that is suitable for encryption applications where nonlinear transformations are required between plaintext and the encrypted data. The application of nonlinear functional chaos-based system with embedded chaotic system and multi-parameters can instigate randomness and diffusion in the data. In addition to high level of randomness, the need for multiple round keys is required in a typical substitution–permutation process. The proposed method eliminates the need for multiple round keys, which is suitable for high-speed communication systems. The statistical experiments performed on the proposed nonlinear transformation algorithms show improvement in encryption strength and resistance against many brute force and statistical attacks. In addition, the proposed system shows high resistance against differential and linear cryptanalysis.