A Chaotic Image Encryption Algorithm Based on Information Entropy

Abstract

This paper proposes an image encryption algorithm based on a chaotic map and information entropy. Unlike Fridrich’s structure, the proposed method contains permutation, modulation, and diffusion (PMD) operations. This method avoids the shortcoming in traditional schemes of strictly shuffling the pixel positions before diffusion encryption. Information entropy is employed to influence the generation of the keystream. The initial keys used in the permutation and diffusion stages interact with each other. As a result, the algorithm acts as an indivisible entity to enhance security. Experimental results and security analyses demonstrate the good performance of the proposed algorithm as a secure and effective communication method for images.

Cryptanalysis of a Chaotic Image Encryption Algorithm Based on Information Entropy

“…times, and from the 201-th iteration, assign the obtained sequence into an M × N matrix P in the raster order, where 1 The transform (5) in [27] can not always generate bijective (one-toone) permutation mapping and should be corrected to assure successful decryption of IEAIE H(X) is the information entropy value of image block X, namely…”

“…In [27], various aspects of IEAIE were analyzed to conclude that it owns superior security performance. However, we try to demonstrate that all the arguments are groundless.…”

“…Unfortunately, IEAIE did not follow the lessons summarized in [18], [24], [25]. To attract the attention of designers of image encryption schemes on cryptanalysis, we check the security of every aspect of IEAIE and its test given in [27] as follows.…”

“…1, 2, the cycle length of the functional graph of 2D-LASM is very small for either arithmetic format. In [27], it was stated that "previously iterated values were discarded to avoid transient effects". Actually, the differences between neighboring states change exponentially along an orbit of any iterated map, which is different from the case for chaotic flow.…”

“…In [27], a chaotic image encryption algorithm was proposed using information entropy value calculated from the plain-image, which is named as IEAIE in this paper. In the algorithm, a pseudo-random number sequence generated by the two-dimensional Logistic-adjusted-Sine map (2D-LASM) proposed in [6] is used to control a combination of some basic operations, including position permutation and modulo addition.…”