Comment on 'An image encryption algorithm based on modified logistic chaotic map'

摘要

A modified logistic map is presented by Han [1] that claims to overcome the issue of the small key space, by exhibiting infinite key space. This paper presents the analysis of the map for a large range of positive and negative control parameter. A strikingly divergent dynamic nature is observed, which is in contrast to the properties proposed in Han (2018). This paper has facilitated to identify the non-chaotic range in the modified logistic map with bifurcation diagram, Lyaponov exponent and phase portrait, which emphasizes the infeasibility of the key space. Therefore, a key which is randomly chosen from the modified logistic map may be in the non-chaotic band. Consequently, this leads to a weak image encryption, which makes it vulnerable to security attacks.