Hierarchical encryption in WDM optical network links

In telecommunication networks and in computer grid networks, a significant ongoing research is in a technology known as wavelength division multiplexing (WDM), which is capable to transport more than 1 Tbps aggregate traffic over a single fiber. However, when massive amounts of information are transported, as in optical networks, there are three issues that stand, cost-efficient ultra-high bandwidth delivery, security of information and data, and security of the network and of the transporting link layer. In optical networks, each fiber link consists of segments, each several kilometers long. Since a single WDM channel carries traffic, there are opportunities for sophisticated eavesdroppers to tap the fiber, copy a channel, isolate a specific payload and attempt to decrypt it if the encryption key is known or it is breakable with a fast computer. Therefore, end-to-end data security should not only rely on the client´s encryption method but also on securing the transmission method on the optical link. In this paper, we present a WDM link security methodology that encrypts multiple channels and with multiple keys to render channel monitoring by eavesdroppers virtually impossible. Although our paper presents the applicability of the method on a point-to-point topology, it is applicable to a multilink and edge-to-edge network path.