Applying Cryptographic Techniques for Securing the Client Data Signals on the Egyptian Optical Transport Network

Abstract

The physical layer of the optical transport network (OTN) is the weakest layer in the network, as anyone can access the optical cables from any unauthorized location of the network and stat his attack by using any type of the vulnerabilities. The paper discusses the security threats and the practical challenges in the Egyptian optical network and presents a new technique to protect the client’s data on the physical layer. A new security layer is added to the OTN frames for the first time since the network infrastructure has been installed. The design of the proposed security layer is done by using a structure of XOR, a linear feedback shift register (LFSR), and random number generator in a synchronous model. We propose the security model for different rates in the OTN and wavelength division multiplexing (WDM) system. The proposed model is implemented on the basis of protecting the important client signals only over the optical layers by passing these signals into extra layer called security layer, and before forming the final frame of the OTN system, this done by adding a new card in the Network Element (NE) to perform this job. The results show that the proposed model of the OTN encryption scheme is providing a high security against any wiretapping attack. If the attacker has the ability to access the fiber cables from any unauthorized location, he will find encrypted data and many years will be needed to find one right key to perform the decryption process.