Visually Meaningful Image Encryption Scheme Based on DWT and Schur Decomposition

Table 3

The NIST test for the encrypted image with size 1024 × 2014.

Statistical test	value	Results
The frequency (monobit) test	0.1977	Pass
Frequency test within a block	0.8234	Pass
The runs test	0.6573	Pass
Tests for the longest run of ones in a block	0.4794	Pass
The discrete Fourier transform (spectral) test	0.6218	Pass
The nonoverlapping template matching test	0.6954	Pass
The overlapping template matching test	0.4796	Pass
Maurer’s “universal statistical” test	0.8838	Pass
The linear complexity test	0.5744	Pass
The serial test	1.0000	Pass
Cusums-forward	0.8580	Pass
Cusums-reverse	1.0000	Pass
The random excursions’ test	0.9651	Pass
The random excursions’ variant test	0.3932	Pass