Phase mask generation for DRPE method using chaos theory and hash function

The aim of this paper is to increase security of double random phase encoding (DRPE) method using chaos theory and hash function for phase mask generation. DRPE encodes the input image by the use of two keys which are random phase masks. Having these keys, the original image can be easily obtained with the reverse process, called decoding. To enhance the system's security, instead of sending random phase masks, initial conditions and parameter of two dimensional coupled logistic map and SHA-512 algorithm are transferred to the authorized user through a secure channel. The proposed method not only obviates the need for sending large phase masks, but it considerably increases DRPE security. Experimental results and computer simulation demonstrate promising results of the proposed technique.