An Improved Secure Image Encryption Algorithm Based on Rubik's Cube Principle and Digital Chaotic Cipher

Table 2

Difference measures between original and shuffled or encrypted images.

Image	NPCR [%]	UACI [%]	MAE [%]	Test conditions
				𝛼	𝛽1	𝛽2
Shuffled	≪80	≪5	≪10		0 <𝛽1< 10	0 < 𝛽2 < 10
	97.7104	13.3053	33.9286		10≤⋯≤10^2	10≤⋯≤10^2
	99.2668	22.7348	57.9737	1	10^2<⋯≤10^3	10^2<⋯≤10^3
	99.3950	23.4347	59.7585		10^3<⋯≤10^4	10^3<⋯≤10^4
	99.4068	23.4454	59.7858		10^4<⋯≤10^5	10^4<⋯≤10^5
	99.4476	23.7236	60.4951	10<𝛼≤10^2	10^2<⋯≤10^3	10^2<⋯≤10^3
	99.4541	23.7657	60.6026	10^2<⋯≤10^3
	99.4629	23.7697	60.7253	10^3<⋯≤10^4
	99.4673	23.7701	60.7284	10^4<⋯≤10^5
	99.6078	30.5903	78.0053	1	10^2<⋯≤10^3	10^2<⋯≤10^3
Encrypted	99.6090	30.5699	77.9533	10<𝛼≤10^2
	99.6120	30.5997	78.0292	10^2<⋯≤10^3