Color Image Encryption Algorithm Based On Chaotic Systems And Zigzag Transformation

With the rapid development of network communication,information security technology has entered the digital era.Image encryption technology is widely used in the field of data communication and data storage,which plays an important role in image confidentiality.Two color image encryption algorithms based on chaos and Zigzag transformation are proposed to solve the problems of strong R,G,B component correlation and low security of existing Zigzag transformaions.A color image encryption algorithm based on chaos,3D Zigzag transformation and view planes is proposed.It adopts a diffusion-permutation-diffusion structure.The view planes of color image are defined and applied in both diffusion stages,which can greatly improve the security of the algorithm.At permutation stage,a 3D Zigzag transformation is proposed to destroy the correlation among R,G,B components.Moreover,two chaotic systems are combined with modular calculation as a new pseudo-random number generator.The other algorithm adopts chaotic system,a new random blocked Zigzag transformation and bit calculation.At permutation stage,proposed Zigzag transformation is implemented on small blocks for multiple times,which lowers horizontal colleration and texture feature of normal Zigzag transformation.At confusion stage,bit calculation is adopted with a six-sided star model,which enhances the security of proposed algorithm.Simulation experiment,key space analysis and encryption efficiency analysis on encryption algorithms and comparison algorithms are performed.The information entropy analysis,pixel correlation analysis,and differential attack analysis of ciphertext images and the experimental data show that both proposed color image encryption algorithms can resist a variety of common attacks,and have good security and encryption efficiency.There are 49 figures,25 tables and 93 references in this thesis.