A novel fast and secure chaos-based algorithm for image encryption

Abstract

Now in cryptography, the key challenge is to consider the trade-offs between the security level and speed performance. In this paper, a fast and secure algorithm for image encryption scheme based on chaotic generators is proposed. In the proposed method, permutation diffusion design is used to create computationally secure encryption primitives and the integer sequences obtained by the sorting of chaotic Logistic map generator by descending order is used as the permutation key to shuffle the whole image. The iteration of the chaotic Skew Tent map is applied after, with an exclusive-or scheme to change the value of the entire pixel, in order to increase the entropy of encrypted image. Moreover, to further enhance the security of the cryptosystem, the keystream used in diffusion process is updated for each pixel and the computed encrypted pixel values depends on both the previously encrypted pixels and the random keystream. The proposed algorithm can resist the statistical and differential attacks. It also passed the information entropy and key sensitivity test. Experimental results indicate that the proposed algorithm has satisfactory speed and high security which makes it a very good candidate for real-time of multimedia data encryption applications.