A novel image encryption system merging fractional-order edge detection and generalized chaotic maps

Abstract

This paper presents a novel lossless image encryption algorithm based on edge detection and generalized chaotic maps for key generation. Generalized chaotic maps, including the fractional-order, the delayed, and the Double-Humped logistic maps, are used to design the pseudo-random number key generator. The generalization parameters add extra degrees of freedom to the system and increase the keyspace achieving more secure keys. Fractional order edge detection filters exhibited better noise robustness than the conventional integer-order ones, rendering the system to be suitable for medical imaging security. The proposed system flexibly integrate different edge detectors, as well as various logistic maps for key generation. The sensitivity of the chaotic maps to all parameters guarantees the encryption system key sensitivity. Security analyses aspects assure the efficiency of the proposed algorithm performance, having high pixel correlation coefficients and flat histograms of cipher images reported. A comparison between the proposed scheme with existing cryptosystems is also presented, regarding histogram uniformity, contrast analysis, Shannon entropy measurements. Compared to the state of the art algorithms, the proposed algorithm has higher statistical and cryptanalytic properties.