Dense wavelength division multiplexing optical networks transport a huge aggregate traffic exceeding Tbps per single fiber, and passive optical network technology has been extended to include the residential and enterprise network layer with fiber-to-the premises. Because this network allows for multimedia and extremely high data rates to end-users, optical communications security is important not only on the client and the node management layers, but also on the physical layer. Thus, cyber-security becomes also important in optical networks, including unbreakable cipher keys, cipher key distribution, identification of malicious actors, source authentication, physical link signature, and countermeasure strategies. In this paper we overview the security of the WDM optical network. We discuss advanced cryptographic methods that stem from quantum mechanics, known as quantum cryptography, and we identify specific vulnerabilities. We also look into the security of the next-generation optical network.
Dense wavelength division multiplexing optical networks transport a huge aggregate traffic exceeding Tbps per single fiber, and passive optical network technology has been extended to include the residential and enterprise network layer with fiber-to-the premises. Because this network allows for multimedia and extremely high data rates to end-users, optical communications security is important not only on the client and the node management layers, but also on the physical layer. Thus, cyber-security becomes also important in optical networks, including unbreakable cipher keys, cipher key distribution, identification of malicious actors, source authentication, physical link signature, and countermeasure strategies. In this paper we overview the security of the WDM optical network. We discuss advanced cryptographic methods that stem from quantum mechanics, known as quantum cryptography, and we identify specific vulnerabilities. We also look into the security of the next-generation optical network.
The last two decades have witnessed an exciting advanced research field that stems from non-classical atomic theory, quantum mechanics. This field promises an important applicability in secure data communications, known as quantum cryptography. Quantum cryptography takes advantage of the inherent random polarization state of single photons, which is not reproducible by a third party or an eavesdropper located between the source and the destination. Thus, when polarization states of photons are associated with binary logic an algorithm may intelligently developed according to which a cryptographic key is disseminated by the source terminal to the destination. This is a process known as quantum key distribution. However, as photons propagate in a non-linear medium such as fiber, their polarization state does not remain intact and thus the quantum key distribution and quantum cryptography becomes vulnerable to attacks. In this paper we consider the applicability of quantum cryptography in a pragmatic fiber-optic medium and in a popular communication network topology. We identify major weaknesses for each step of the quantum key distribution process, and also potential attacks to incapacitate quantum cryptography in fiber communications, so that better countermeasure strategies can be developed.
The secure transport of messages was the concern of many early civilizations. Since then, different methods have been developed to assure that only the sender and the addressee would be able to read a message, while it would be illegible or without significant meaning to a third party. Today, this practice continues with more fervor. Wireless, wired, and optical communication networks are able to transport unimaginable amounts of data and thus privacy of information and security of the network are of the utmost concern because a good part of the transported information may be very sensitive and/or confidential. Confidentiality of information has been particularly popularized with the explosive growth of the Internet, which has touched most people's lives. However, from the outset, the Internet was based on open network architecture with computer-based nodes and without network security, and thus was vulnerable to attackers and hackers. Wireless networks transmit in unguarded space and thus are also subject to malicious actors. Dense wavelength-division multiplexing (DWDM) optical networks transport a massive aggregate traffic that has exceeded terabits per second per single fiber; therefore, the issues of information privacy and network security are equally important. As a result, the development of unbreakable cipher keys, cipher-key distribution, identification of malicious actors, source authentication, physical-link signature identification, countermeasures, and so forth has been the major thrust of research efforts with regard to cyber-security. This article focuses on cryptography, and is the first of a series of three articles on cryptography and security in communications. Subsequent articles will cover wireless and IP network security, as well as optical network security, quantum cryptography, and quantum-key distribution processes specific to optical networks.
The increased demand of data services within the last few years has prompted a commensurate explosion in transportable bandwidth, most of which contain sensitive information, personal data, bank accounts, credit card numbers, proprietary documents, and more. As a result, there are two types of security in communications, securing user data and securing the physical network. The first is addressed with encryption algorithms, the unbreakability of which does not depends so much on the sophistication of the algorithm but on the difficulty to break it using a sequential computer; that is, it capitalizes on the inability of the attacker to use a fast supercomputer. The second is not a well addressed topic, particularly in modern fiber-optic networks. One attempt to create an unbreakable cipher-text is quantum cryptography that emanated from quantum mechanics; this method capitalizes on the no-cloning principle of particular characteristics of photons, such as polarization. In this paper, we examine the security of advanced optical networks, fiber-optic and free space optical (FSO). We describe quantum cryptography and the quantum key distribution, including the principle of teleportation, we identify vulnerabilities and we discuss detection mechanisms and countermeasure strategies against attacks on the physical network.
The last two decades have witnessed an exciting advanced research field that stems from non-classical atomic theory, the quantum mechanics. This research promises an interesting applicability in computation, known as quantum computation, and also in secure data communications, known as quantum cryptography. Quantum cryptography capitalizes on the inherent random polarization state of single photons, which are associated with binary logic values. Because the polarization state of a photon is not reproducible by an eavesdropper between the source and the destination, polarized photons are used with an intelligent algorithm to disseminate the cryptographic key with high security from the source to the destination, a process known as quantum key distribution. However, although the polarization state of a photon remains intact in free-space propagation, it does not remain so in dielectric medium and thus quantum cryptography is not problem-free. In this paper we review quantum cryptography and we identify the various steps in the quantum key identification process. We then analyze and discuss issues related to quantum key distribution that rise in pragmatic fiber-optic transmission and in communication network topologies. In addition, we identify a major weakness of the method that is prone to attacking and which incapacitates quantum cryptography in fiber communications.
The last two decades have witnessed an exciting advanced research field that stems from non-classical atomic theory, the quantum mechanics. This research promises an interesting applicability in computation known as quantum computation, and also in secure data communications, known as quantum cryptography Quantum cryptography capitalizes on the inherent random polarization state of single photons, which are associated with binary logic values. Because the polarization state of a photon is not reproducible by an eavesdropper between the source and the destination polarized photons are used with an intelligent algorithm to disseminate the cryptographic key with high security from he source to the destination, a process known as quantum key distribution. However, although the polarization state of a photon remains intact in free- space propagation, it does not remain so in dielectric medium and thus quantum cryptography is not problem- free. In this paper we review quantum cryptography and we identify the various steps in the quantum key identification process. We then analyze and discuss issues related to quantum key distribution that rise in pragmatic fiberoptic transmission and in communication network topologies. In addition, we identify a major weakness of the method that is prone to attacking and which incapacitates quantum cryptography in fiber communications.
It is well known that optical access networks are able to provide high data rates over long distances and to a reasonable number of users. Security and privacy are always a challenge for public accessible network infrastructures. Especially in time-division multiplexing passive optical networks (TDM-PONs), in which the downstream signal is broadcasted to all users connected via the same wavelength channel in a shared fiber link, privacy can be a critical concern. Although encryption at the application layer can provide a high level of security, this can be achieved only if the encryption key distribution is perfectly save. On the other hand, encryption on the physical layer such as quantum cryptography or, more precisely, quantum key distribution (QKD) is a very promising approach to achieve secure communication. However, there remain several issues that have to be solved before the quantum cryptography reaches the maturity level needed for a cost effective implementation in practical networks. In this paper, we address quantum key distribution (QKD) over passive optical access networks, which is an enabling technology required to cost efficiently deploy practical quantum encrypted data communication in the access area. We study different methods to integrate QKD systems in conventional optical access networks and quantitatively evaluate their suitability for a potential implementation.