Virtual optical encryption using phase shifted digital holography and RSA algorithm

摘要

Optical image encryption is one of the most promising technologies being investigated in the field of data communication, information technology and cloud computing. In this paper, a novel image encryption system based on virtual optical technique, phase shifted digital holography and RSA public key exchange is proposed. In the system, the encryption keys include the wavelength of the laser beam, focal length of the test lens, defocusing distance and scaling factor. The plain text image is encrypted to a cipher by using a phase shifted hologram function. The decryption process involves the phase calculation using phase shifting and sequential line scan algorithms. The keys are exchanged between sender and receiver by using RSA key exchange algorithm. To determine accuracy of the information retrieved by the proposed technique; the mean square error is calculated between the original image and retrieved image.