title: Security Analysis of Image Encryption Based on Gyrator Transform by Searching the Rotation Angle with Improved PSO Algorithm.
abstract: Gyrator transform has been widely used for image encryption recently. For gyrator transform-based image encryption, the rotation angle used in the gyrator transform is one of the secret keys. In this paper, by analyzing the properties of the gyrator transform, an improved particle swarm optimization (PSO) algorithm was proposed to search the rotation angle in a single gyrator transform. Since the gyrator transform is continuous, it is time-consuming to exhaustedly search the rotation angle, even considering the data precision in a computer. Therefore, a computational intelligence-based search may be an alternative choice. Considering the properties of severe local convergence and obvious global fluctuations of the gyrator transform, an improved PSO algorithm was proposed to be suitable for such situations. The experimental results demonstrated that the proposed improved PSO algorithm can significantly improve the efficiency of searching the rotation angle in a single gyrator transform. Since gyrator transform is the foundation of image encryption in gyrator transform domains, the research on the method of searching the rotation angle in a single gyrator transform is useful for further study on the security of such image encryption algorithms.
authors.affiliation: Key Laboratory of Dependable Service Computing in Cyber Physical Society of Ministry of Education, Chongqing University, Chongqing 400044, China. jsang@cqu.edu.cn.|School of Software Engineering, Chongqing University, Chongqing 401331, China. jsang@cqu.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Sang
authors.affiliation: School of Automation, Huazhong University of Science and Technology, Wuhan 430074, China. zhaojunhust@gmail.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Dependable Service Computing in Cyber Physical Society of Ministry of Education, Chongqing University, Chongqing 400044, China. taizixzl@gmail.com.|School of Software Engineering, Chongqing University, Chongqing 401331, China. taizixzl@gmail.com.
authors.forename: Zhili
authors.initials: Z
authors.lastname: Xiang
authors.affiliation: Key Laboratory of Dependable Service Computing in Cyber Physical Society of Ministry of Education, Chongqing University, Chongqing 400044, China. caibin@cqu.edu.cn.|School of Software Engineering, Chongqing University, Chongqing 401331, China. caibin@cqu.edu.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Cai
authors.affiliation: Key Laboratory of Dependable Service Computing in Cyber Physical Society of Ministry of Education, Chongqing University, Chongqing 400044, China. xianghong@cqu.edu.cn.|School of Software Engineering, Chongqing University, Chongqing 401331, China. xianghong@cqu.edu.cn.
authors.forename: Hong
authors.initials: H
authors.lastname: Xiang
keywords: gyrator transform; image encryption; intelligent search; particle swarm optimization (PSO); rotation angle