Confidential Enhancement with Multi-code Keying Reconfiguration over Time-Shifted CHPC-based 2D OCDMA Networks

In order to overcome vulnerability to eavesdropping of on-off-keying based OCDMA scheme, a new multi-code keying reconfiguration is presented to enhance confidentiality over two dimensional time-spreading and wavelength-hopping (2D TS/WH) optical code division multiple access (OCDMA) schemes. The time-shifted carrier-hopping prime codes (CHPCs) are proposed and assigned as signature address code. This proposed scheme provides the integration of electronic and optical layer domain, which inherently comes from the data encryption and spectrum-spreading of the transmitted signals, and then achieve data-confidential enhancement in synchronous networks. Moreover, multi-code keying reconfiguration in a set of distinct codeword is assigned to each user and randomly selection by using thin film filter, tunable delay line and optical switch. Here, the proposed scheme using shifted CHPC appears to be a promising coding type for generating OCDMA code space that are large enough to prevent successful brute force code search attacks. In addition, the probability of interception performance in terms of various multi-code key numbers per user is analyzed. The result shows that the confidentiality is enhanced to combat against eavesdropping while signature address code number per uses is increased in proposed multi-code key reconfiguration scheme.