An Image Encryption Scheme Based on Lorenz Hyperchaotic System and RSA Algorithm

Table 1

Randomness test by NIST SP800-22 for the Lorenz hyperchaotic system’s sequences.

Test name	P value	Result
The frequency test	0.8823	Pass
Frequency test within a block (block = 10000)	0.7208	Pass
The runs test	0.6031	Pass
Tests for the longest-run-of-ones in a block	0.0798	Pass
The binary matrix rank test	0.1220	Pass
The discrete Fourier transform test	0.8164	Pass
The nonoverlapping template matching test (m = 10)	0.2990	Pass
The overlapping template matching test (m = 9, template = 111111111)	0.4298	Pass
Maurer’s “universal statistical” test	0.4561	Pass
The linear complexity test (block = 1000)	0.6040 [0.6013, 0.3395]	Pass
The serial test (test 1 and test 2)	0.1395	Pass
The approximate entropy test	[0.4992, 0.5407]	Pass
The cumulative sums test (forward and reverse test)	0.8008	Pass
The random excursions test (x = −1)	0.9104	Pass
The random excursions variant test (x = 1)	0.6031	Pass