Image encryption using complex hyper chaotic system by injecting impulse into parameters

摘要

To resist the finite precision of computer that leads chaotic sequence into periodic orbits, and enhance the complexity of chaotic trajectory to mitigate the dynamical degradation, we investigated the complex hyper chaotic Lü system, and analyzed its nonlinear dynamical behavior by chaotic attractors, Lyapunov exponents, and bifurcation diagrams. The novelty is to mitigate the dynamical degradation and enhance the randomness of the chaotic system through injecting impulse into control parameter. To investigate its application in cryptography, we used the perturbed system by impulse to encrypt color image, three time-saving bitwise operations are adopted to speed up the encryption process. One-time-keys with larger key space sampled from noise made the algorithm resistant to brute-force, known-plaintext, chosen-plaintext, chosen-cipher and differential attacks. Numerical simulation and statistical analysis demonstrated excellent performance of the perturbed complex hyper chaotic system and application in image encryption.