Image Encryption Performance Evaluation Based on Poker Test

Table 8

Evaluation results of the cipher text image in Figure 5.

	The proposed metric			Normalized autocorrelation			Gap test			Entropy
				Horizontal	Vertical	Diagonal	20%	50%	70%
Figure 5(b)	0.337	325.96	322.42	0.0627	−0.075	−0.061	172290	2504.5	2221.7	7.4442
Figure 5(c)	0.071	320.85	321.63	0.0009	−0.006	0.0023	91872	2666.9	17.1381	7.9967
Figure 5(d)	0.066	320.45	320.25	−0.003	0.0028	0.0081	94411	2823.1	14.51	7.9967