Securing Digital Images through Simple Permutation-Substitution Mechanism in Cloud-Based Smart City Environment

Table 2

Comparisons of encryption time (in seconds) for the proposed image cryptosystem with related cryptosystems for different sizes of images.

Encryption scheme	Image size
	256 × 256	512 × 512	1024 × 1024
Our proposed method	0.0494	0.3033	1.0453
Ref. [10]	0.0779	0.3261	1.3146
Ref. [15]	0.0538	0.2338	1.1494
Ref. [16]	0.1789	0.6639	3.1426
Ref. [23]	0.0949	0.4010	1.9857