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

Table 15

Comparison of our cryptosystem with other related cryptosystems in terms of average values of Chi-square, contrast, and PSNR.

Cryptosystem	Chi-square	Contrast	PSNR
Our approach	250.51217	10.50209	8.21239
Ref. [11]	257.33667	—	—
Ref. [14]	249.42857	—	—
Ref. [25]	249.84440	—	—
Ref. [26]	—	10.43525	8.53790
Ref. [28]	256.75146	10.62060	8.41076