Entropy-Based Block Scrambling Image Encryption Using DES Structure and Chaotic Systems

Table 3

Correlations of original images and encrypted images.

Schemes	Images	Original image			Encrypted image
		Horizontal	Vertical	Diagonal	Horizontal	Vertical	Diagonal
This study	Lena	0.9677	0.9358	0.9020	0.0048	0.0001	0.0018
	Cameraman	0.9543	0.9131	0.8984	−0.0055	0.0048	−0.0011
	Fingerprint	0.7739	0.8153	0.6151	−0.0006	−0.0026	−0.0020
Ref. [34]	Lena	—	—	—	−0.0796	0.0166	0.0032
	Cameraman	—	—	—	−0.0398	−0.0387	−0.0090
Ref. [35]	Lena	0.9721	0.9739	0.9705	−0.0029	−0.0017	0.0004
	Cameraman	0.9634	0.9732	0.9449	0.0047	−0.0066	0.0031