Color Image Encryption Algorithm Based on Dynamic Block Zigzag Transformation and Six-Sided Star Model

Abstract

As a result of the rise in network technology, information security has become particularly important. Digital images play an important role in network transmission. To improve their security and efficiency, a new color image encryption algorithm is proposed. The proposed algorithm adopts a classical scrambling–diffusion framework. In the scrambling stage, the dynamic block Zigzag transformation is designed by combining the chaotic sequence with the standard Zigzag transformation, which can dynamically select the transformation range and the number of times. It is used to scramble the pixel positions in the R, G, and B components. In the diffusion stage, the six-sided star model is established by combining the chaotic sequence and the six-sided star structure characteristics, which can store the 24 bits of the pixel in a defined order to realize bit-level diffusion operation. Experimental analyses indicate that our algorithm has the characteristics of high key sensitivity, large key space, high efficiency, and resistance to plaintext attacks, statistical attacks, etc.