Second-Order Chaotic Maps With Random Coefficients to Generate Complex Chaotic Sequences for High-Security Image Encryption
Ta-Chien Yeh, Jean‐Fu Kiang · IEEE Access · 2023
Chaotic maps have been widely applied on image encryption for their complexity and sensitivity to key variation. In this work, we propose second-order chaotic maps with optimized random coefficients to generate chaotic sequences for image encryption. Two screening conditions are proposed to identify 300 candidate chaotic maps in terms of complexity indicesKand SE. A particle swarm optimization algorithm is developed to search for the optimal chaotic maps under eight different weighting schemes. The optimal chaotic maps can achieveNp= 2,DKY= 2, CD= 2,K> 0.9, SE> 0.9 and PE> 0.7. Key sensitivity analysis on all the system parameters and initial values confirms high security of the optimal chaotic maps. A hybrid sequence generation (HSG) scheme is also proposed to further reduce the image encryption time.