A Virtual Optical Holographic Encryption System Using Expanded Diffie-Hellman Algorithm

This paper presents a new method for encrypting information over a Virtual Optical Holographic Encryption (VOHE) system which employs a virtual optical system based on digital holography and Fourier lens. The VOHE system provides parameters such as propagation wavelength (λ) and focal length (f) of the Fourier lens which are keys that are used for encryption and decryption processes. The encrypted holographic information is based on an expanded Diffie-Hellman (EDH) algorithm. The method of expansion is presented based on a two-dimension complex function EDH-C. Furthermore, an expanded Pollard's Rho method was applied to evaluate the security of the proposed EDH-C algorithm. To determine the accuracy of the information retrieved by a receiver site, the mean absolute error (MAE) was calculated between the original code and retrieved code. Finally, the randomness of the transmitted message for both methods was evaluated using NIST tests and the results show that the message that was encrypted by the proposed EDH-C algorithm had higher security than DH in view of the unpredictability and complexity of the transmitted message over an insecure channel.