A Novel Chaos-based Image Encryption Scheme with an Improved Permutation Process

Abstract

Confidentiality is an important issue when digital images are transmitted over public networks, and encryption is the most useful technique employed for this purpose. Image encryption is somehow different from text encryption due to some inherent features of image such as bulk data capacity and high correlation among adjacent pixels, which are generally difficult to handle by conventional algorithms. Recently, chaos-based encryption has suggested a new and efficient way to deal with the intractable problems of fast and highly secure image encryption. This paper proposes a chaos-based cryptosystem with a novel permutation process for secure and efficient image protection. To improve the security of the confusion module, an improvement is made to the conventional confusion-diffusion architecture by introducing a certain diffusion mechanism in confusion stage through a lightweight bitlevel permutation algorithm. As a result, the diffusion performance is significantly enhanced and hence the overall security of the image cryptosystem is promoted. Results of various types of analysis indicate that the proposed scheme provides a good balance between security and speed and hence suitable for real-time secure image communication applications.