Multilevel image encryption by binary phase XOR operations

We propose a multilevel image encryption by using binary phase exclusive-OR(XOR) operations and image dividing technique. The multilevel image can be divided to binary images that have same gray levels. We convert each binary image to binary phase image by phase encoding and encrypt these images with binary random phase images by binary phase XOR operation. We make encrypted gray image by combining each binary encrypted images. We implement the decryption process with joint transform correlator (JTC) and verify the proposed method by computer simulation.