Space Division Multiplexing (SDM) is a promising solution to provide ultra-high capacity optical network infrastructure for rapidly increasing traffic demands. Such network infrastructure can be a target of deliberate attacks that aim at disrupting a large number of vital services. This paper assesses the effects of high-power jamming attacks in SDM optical networks utilizing Multi-Core Fibers (MCFs), where the disruptive effect of the inserted jamming signals may spread among multiple cores due to increased Inter-Core CrossTalk (ICo-XT). We first assess the jamming-induced reduction of the signal reach for different bit rates and modulation formats. The obtained reach limitations are then used to derive the maximal traffic disruption at the network level. Results indicate that connections provisioned satisfying the normal operating conditions are highly vulnerable to these attacks, potentially leading to huge data losses at the network level.
Space Division Multiplexing (SDM) is a promising solution to provide ultra-high capacity optical network infrastructure for rapidly increasing traffic demands. Such network infrastructure can be a target of deliberate attacks that aim at disrupting a large number of vital services. This paper assesses the effects of high-power jamming attacks in SDM optical networks utilizing Multi-Core Fibers (MCFs), where the disruptive effect of the inserted jamming signals may spread among multiple cores due to increased Inter-Core CrossTalk (ICo-XT). We first assess the jamming-induced reduction of the signal reach for different bit rates and modulation formats. The obtained reach limitations are then used to derive the maximal traffic disruption at the network level. Results indicate that connections provisioned satisfying the normal operating conditions are highly vulnerable to these attacks, potentially leading to huge data losses at the network level.
On the one hand, Quantum key distribution (QKD) offers unparalleled security relying on the principles of quantum mechanics. On the other hand, space division multiplexing (SDM) is recognized as the route toward a capacity upgrade for current core optical communication networks and will progressively permeate into shorter-reach networks. Incorporating QKD into classical networks, with SDM being one of its components, will enhance data communication security. Understanding the security implications of implementing QKD over SDM is crucial for the practical deployment of quantum-secure communication technologies, especially in scenarios where high data capacity and multiplexing techniques are essential. In this paper, we study a QKD eavesdropping use case where connectivity is provided via SDM fibers. Specifically, we discuss the detector blinding attack (DBA) concerning inter-core crosstalk in an entanglement based QKD system. Additionally, we analyze the blinding power of DBA over quasi-homogeneous and heterogeneous seven-core fiber scenarios. Furthermore, the potential countermeasures to mitigate the impact of such attacks are discussed.
The integration of Quantum Key Distribution (QKD) into optical networks has emerged as a promising solution for securing sensitive data transmission in mobile fronthaul applications. However, implementing QKD typically requires dedicated dark fibers, which increases network complexity and deployment costs. This paper explores an approach that leverages Multi-Core Fibers (MCF) to integrate both classical and quantum channels within the same optical fiber, utilizing Space Division Multiplexing (SDM). By dedicating separate cores for quantum and classical channels, the proposed system minimizes the need for additional infrastructure while ensuring secure and efficient communication. Crosstalk between cores, a critical factor in MCF design, is analyzed through simulations, considering parameters such as core pitch and operating spectrum. Results demonstrate the feasibility of achieving minimal inter-core crosstalk for reliable quantum and classical channel coexistence. This study underscores the potential of MCF-based SDM as a cost-effective and scalable solution for future quantum-secured mobile networks.
Optical multicore and multimode fibers (MCF/MMF) are promised to pace with the capacity crunch of back-bone networks by their spatial domain using space division multiplexing (SDM) [1]. Although multiple channels propagate within the same media in parallel, material inhomogenities and bendings induce inter- and intra-core crosstalk (XT), the compensation of which is crucial for long-haul SDM-fiber deployment [2]. In addition, the inherent XT provides random scattering to be exploited for physical layer security (PLS), either as physical un-clonable function (PUF) [3] or secret key generation (SKG) for end-to-end security [4], [5]. For both, SDM and PLS, the main challenge is to recover the spatial amplitude and phase contributions of each channel at the receiver-side in real-time, e.g. by digital signal processing (DSP). With increased number of SDM channels the computational effort in DSP-based channel diagonalization arises.
Space-division multiplexed (SDM) fiber optic transmission systems can not only increase system capacity, but also achieve physical-layer security against fiber tapping attacks. In this paper, we examine the information-theoretic security of optical multiple-input-multiple-output (MIMO) SDM by evaluating the tradeoff between the achievable information rate and the confidentiality for different channel dynamics. In particular, we provide problem formulations for secure communication over these channels and study three types of secrecy capacities: 1) guaranteed capacity; 2) outage capacity; and 3) average capacity, each serving as a performance metric for a coding strategy tailored to a specific type of MIMO-SDM channel. We also assess the impact of key system parameters, such as the number of modes, the mode-dependent loss (MDL), and the signal-to-noise ratio (SNR), on the various secrecy capacities. Our results indicate that, with a proper design of channel codes that balance information rate and security, an SDM system has the potential of offering confidential data transmission at a rate that could be orders of magnitude higher than what can be achieved through other means of encryption. Moreover, we show that MDL, unavoidably induced by fiber tapping, can allow information-theoretic security even if the SNR of the eavesdropper's receiver is better than that of the legitimate receiver.
Recent developments in the field of space-division multiplexing (SDM) for fiber-optic communication systems suggest that the spatial diversity offered by SDM can be used not only to increase system capacity, but also to achieve provable security against physical layer attacks. We examine the information-theoretic security of SDM with a focus on frequency-selective and rapidly-varying frequency-flat channels. We analytically evaluate the outage-free secrecy capacity - the maximal data rate that guarantees perfect security within a class of channel realizations. Using analysis and simulations, we evaluate the impact of key system parameters on the secrecy capacity of SDM systems. Our results show that, with a proper code design that balances the trade-off between data rate and confidentiality, we can take full advantage of SDM to offer a secure information rate that could be orders of magnitude higher than what can be achieved through quantum key distribution (QKD).
Quantum key distribution (QKD) is regarded as an alternative to traditional cryptography methods for securing data communication by quantum mechanics rather than computational complexity. Towards the massive deployment of QKD, embedding it with the telecommunication system is crucially important. Homogenous optical multi-core fibers (MCFs) compatible with spatial division multiplexing (SDM) are essential components for the next-generation optical communication infrastructure, which provides a big potential for co-existence of optical telecommunication systems and QKD. However, the QKD channel is extremely vulnerable due to the fact that the quantum states can be annihilated by noise during signal propagation. Thus, investigation of telecom compatibility for QKD co-existing with high-speed classical communication in SDM transmission media is needed. In this paper, we present analytical models of the noise sources in QKD links over heterogeneous MCFs. Spontaneous Raman scattering and inter-core crosstalk are experimentally characterized over spans of MCFs with different refractive index profiles, emulating shared telecom traffic conditions. Lower bounds for the secret key rates and quantum bit error rate (QBER) due to different core/wavelength allocation are obtained to validate intra- and inter-core co-existence of QKD and classical telecommunication.