To improve the confidentiality and availability of the network, it is important to provide multilevel security in the physical layer of optical networks. Based on the orthogonal characterization of OFDM, we introduce a new electronic encryption method for the encryption of the subcarriers symbols after data mapping. Since all-optical networks are emerging as implementations for very high data rate communications, flexible switching and broadband application support, we present a novel all-optical security system technique using random sequence encryption. The noise function was applied via a pseudo-random noise generator seeded with an encryption key. We analyze the performance of both security systems under different application circumstances. Our results confirm the effectiveness of the security technique to make the system less vulnerable to attack.
Multiple-Image Hiding Based on Cascaded Free-Space Wave Propagation Using the Structured Phase Mask for Lensless Optical Security System
