Multiple color image cryptosystem based on coupled-logistic-map-biometric keys, QR decomposition with column pivoting and optical Fresnel transform

Abstract

A novel multiple color image cryptosystem based on coupled-logistic-map-biometric keys (CBK), QR decomposition with column pivoting and optical Fresnel transform (FT), is proposed. In this system, the four sub-bands of each primary color image are produced by the discrete wavelet transform (DWT). The LL sub-bands of four images are fused. The fused image is divided into R, G, and B channels. The two sets of channels (R and B) and (G and B) are independently encoded into complex images, scrambled with generalized Arnold transform (GAT) and then decomposed by QRD with column pivoting. A novel concept of single-channel image constructed by adding of Q1.R2 and Q2.R1 modulated with the R channel of CBK is introduced because the parameters of the coupled logistic map and uniqueness of iris image protect against unauthorized access. The single-channel image is modulated by G channel of CBK and then Fresnel transformed. The phase and amplitude truncation operations are applied to the resultant image to obtain the first cipher image and the first phase key, respectively. The first cipher image is modulated by B channel of CBK and then Fresnel transformed. Finally, the phase and amplitude truncation operations are performed to the transformed image to get the final cipher image and the second phase key, respectively. Two decryption keys produced by QR decomposition with column pivoting and two-phase keys are asymmetric keys to resist potential attacks. Moreover, the parameters of the coupled logistic map (in R, G, and B channels of CBK), GAT and FT supply a large key space of the cryptosystem. A hybrid opto-electronic system can be used to perform the proposed approach. Numerical simulations demonstrate the validity and viability of the proposed scheme.