A New Image Encryption Scheme Based on Hybrid Chaotic Maps

Algorithm 2

Proposed encryption process.

	Input: plain image P
	Output: cipher image C
	Begin
	//Permutation Process Step 1: examine the plain image P in size M × N. P can be a gray-scale or RGB image. Step 2: decompose the image into four level sub-bands (LL, LH, HL, and HH) by the selected DWT. Step 3: choose a two-dimensional chaotic system and generalize it by introducing the initial values , these initial values as secret keys. Step 4: generate the chaotic sequences using the proposed chaotic maps and set the appropriate values of the secret keys. Can use the 1^st proposed chaotic map. Step 5: change the chaotic sequence, with the same method, into a consistently dispersed grouping by altering the initial values and parameters. Step 6: iterate the chaotic sequence for LL sub-band for scrambling LLP row by row and column by column (starting from the first row and the first column) Step 7: like step 3, compute the next quantized chaotic pair using the 2^nd, 3^rd, and 4^th proposed chaotic maps to scramble the next sub-bands of LH, HL, and HH, respectively, and reiterate this step total times. (When the last row or the last column has been scrambled, switch to the first row or the first column over again.) Step 8: combine the chaotic vectors (LLP, LHP, HIP, and HHP) into one vector with in size M × N. Step 9: make the new vector of mistook pixels for in size M × N as  //Diffusion Process Step 10: adjust and change the vector SP realizing that every component of level gray ranges in [0, 255] utilizing the accompanying condition:  Step 11: create the diffused vector with SD in size M × N as follows: , where denotes the exclusive OR operation bit by bit Step 12: create the final matrix with cipher image C as follows:
	End