A new color image encryption scheme using CML and a fractional-order chaotic system

PLoS One. 2015 Mar 31;10(3):e0119660. doi: 10.1371/journal.pone.0119660. eCollection 2015.

Abstract

The chaos-based image cryptosystems have been widely investigated in recent years to provide real-time encryption and transmission. In this paper, a novel color image encryption algorithm by using coupled-map lattices (CML) and a fractional-order chaotic system is proposed to enhance the security and robustness of the encryption algorithms with a permutation-diffusion structure. To make the encryption procedure more confusing and complex, an image division-shuffling process is put forward, where the plain-image is first divided into four sub-images, and then the position of the pixels in the whole image is shuffled. In order to generate initial conditions and parameters of two chaotic systems, a 280-bit long external secret key is employed. The key space analysis, various statistical analysis, information entropy analysis, differential analysis and key sensitivity analysis are introduced to test the security of the new image encryption algorithm. The cryptosystem speed is analyzed and tested as well. Experimental results confirm that, in comparison to other image encryption schemes, the new algorithm has higher security and is fast for practical image encryption. Moreover, an extensive tolerance analysis of some common image processing operations such as noise adding, cropping, JPEG compression, rotation, brightening and darkening, has been performed on the proposed image encryption technique. Corresponding results reveal that the proposed image encryption method has good robustness against some image processing operations and geometric attacks.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms*
  • Image Processing, Computer-Assisted / methods*

Grants and funding

This research was jointly supported by the National Natural Science Foundation of China (No. 61004006, http://www.nsfc.gov.cn), China Postdoctoral Science Foundation(No. 2013M530181, http://res.chinapostdoctor.org.cn/BshWeb/index.shtml), the Natural Science Foundation of Henan Province, China (No. 13230010254, http://www.hnkjt.gov.cn/, Program for Science & Technology Innovation Talents in Universities of Henan Province, China (Grant No 14HASTIT042, http://rcloud.edu.cn), the Foundation for University Young Key Teacher Program of Henan Province, China (No. 2011GGJS-025, http://www.haedu.gov.cn/), Shanghai Postdoctoral Scientific Program (No. 13R21410600, http://www.21cnhr.gov.cn/doctorarea/), the Science & Technology Project Plan of Archives Bureau of Henan Province (No. 2012-X-62, http://www.hada.gov.cn/) and the Natural Science Foundation of Educational Committee of Henan Province, China (No. 13A520082, http://www.haedu.gov.cn/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.