A Non-Linear Equation-Based Cryptosystem for Image Encryption and Decryption(Part 2)
So in the previous part, we have seen the encryption algorithm so know well move on to decryption. The exact reverse process is carried out to decrypt the encrypted output obtained.
The cascade architecture of OPE is shown.
The architecture of OPE 1 is the same as that of EPE2 with qxe and qye are inputs.
The architecture of OPEl is shown.
The architecture of OPE2 is shown. It consists of one subtractor, one modulo inverse operation, one multiplier, and one MOD operation
A. Image To Pixel Conversion So to provide the image as input to EPEs as shown is previous the image has to be converted to corresponding pixel values.
(a) The corresponding matrix is obtained.
B. Generation Of Chaotic Binary Sequence The chaotic signal is used for secure data transmission. The chaotic function that is used is given by equation
C. Generation Of qx And qy The BB equation is used to find qx and qy values. Initially, the x and y values are to be known, for that the BB equation is solved for different values of n.
D. Generation Of qxe And qye The qxe and qye values are obtained for various qx and qy . As per the Architecture of EPE 2, either of the two keys is selected randomly depending on the CB values and added to the qx value.
E. Decryption The exact reverse process is carried out in order to obtain the decrypted image. For this, the encrypted pixels are taken as the input and the corresponding qx and qy values are obtained through OPE I.