A New Chaos-Based Color Image Encryption Scheme with an Efficient Substitution Keystream Generation Strategy

Table 3

Results of NPCR and UACI tests.

Test image name	Number of encryption rounds
	1		2		3		4
	NPCR	UACI	NPCR	UACI	NPCR	UACI	NPCR	UACI
Baboon	0.90905	0.30349	0.99614	0.33460	0.996095	0.33445	0.99609	0.33457
House	0.83127	0.27808	0.99611	0.33483	0.9961407	0.33466	0.99608	0.33446
Lena	0.06218	0.02089	0.99620	0.33469	0.996074	0.33487	0.99619	0.33447
Peppers	0.81662	0.27345	0.99607	0.33448	0.996147	0.33457	0.99608	0.33466
Portofino	0.44400	0.14861	0.99600	0.33443	0.995989	0.33425	0.99603	0.33487