Computational Image Encryption Techniques: A Comprehensive Review

Table 1

Image encryption evaluation parameters.

Evaluation parameter	Abbr.	Expectation
Key space analysis [3]	KA	Large key size (more than )
Histogram analysis [1]	HA	Pixels should uniformly distribute
Information entropy [10]	IE	Equal to 8, for a 256-gray level image
Noise attack [11]	NA	Ought to be safe to noise attacks
Correlation coefficient [12]	CC	Near to 0
Mean squared error [13]	MSE	Minimum
Peak signal-to-noise ratio [2, 14]	PSNR	Low between encrypted and actual images; high between the ciphered and decrypted images
Execution time [2]	ET	Minimum for practical implementation
Number of pixel change rate [15]	NPCR	Maximum value (according to critical analysis, it should be near to 99.609% or more)
Unified average changing intensity [16]	UACI	Minimum value (according to critical analysis, it should be near to 33.464% or more)