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

Table 14

Comparison of our algorithm with other related cryptosystems in terms of average values of correlation, NPCR, UACI, local entropy, and global entropy.

Cryptosystem	Correlation			NPCR (%)	UACI (%)	Information entropy
	Hor.	Ver.	Dia.			Global	Local
Our cryptosystem	−0.00016	0.00002	0.00023	99.62198	33.47181	7.99949	7.90227
Ref. [5]	0.00200	−0.00070	−0.00140	99.65000	33.48000	7.99700	—
Ref. [10]	0.00052	0.00033	0.00087	99.60960	33.45960	7.99930	7.90237
Ref. [11]	−0.00970	−0.00870	0.00650	99.60000	33.44000	7.99700	7.90217
Ref. [12]	−0.00074	0.00120	−0.00320	—	—	7.99830	—
Ref. [14]	0.00219	0.00169	0.00186	99.61100	33.47567	7.99929	7.90238
Ref. [25]	−0.00420	−0.00490	−0.00450	99.6101	33.52520	7.9995	7.90300
Ref. [26]	0.00180	−0.00161	0.00463	99.6225	33.59500	7.99301	—
Ref. [28]	0.00050	0.00170	−0.00250	99.60667	33.42667	7.99866	—