The combination of network virtualization (NV) technology and elastic optical networks (EONs) can further improve the flexibility of network resource allocation while bringing new security risks. For EONs are vulnerable to eavesdropping attacks by third parties, the security of data transmission in virtual optical network (VON) cannot be guaranteed. Quantum key distribution (QKD) provides verified unconditional security based on quantum entanglement properties. EONs integrated with QKD, as the physical network for virtual optical network embedding (VONE), can improve the security of VON. In addition, the survivability of VONE is a critical requirement. So, a shared protection survivable multipath-based VONE in EONs integrated with QKD (SPSMP-VONE) algorithm is discussed for solving the VONE problem under the single-link failure scenario. Specifically, the process of virtual link embedding is divided into the phase of ciphertext data transmission path embedding and the phase of key distribution path embedding. The phase of ciphertext data transmission path embedding adopts multipath shared protection strategy with spectrum partitioning. And the phase of key distribution path embedding design a path splitting strategy when the key resources as well as spectrum resources are insufficient on a single path. Simulation results demonstrate that the SPSMP-VONE algorithm can effectively improve the spectrum utilization ratio and key utilization ratio by up to 12%.
The combination of network virtualization (NV) technology and elastic optical networks (EONs) can further improve the flexibility of network resource allocation while bringing new security risks. For EONs are vulnerable to eavesdropping attacks by third parties, the security of data transmission in virtual optical network (VON) cannot be guaranteed. Quantum key distribution (QKD) provides verified unconditional security based on quantum entanglement properties. EONs integrated with QKD, as the physical network for virtual optical network embedding (VONE), can improve the security of VON. In addition, the survivability of VONE is a critical requirement. So, a shared protection survivable multipath-based VONE in EONs integrated with QKD (SPSMP-VONE) algorithm is discussed for solving the VONE problem under the single-link failure scenario. Specifically, the process of virtual link embedding is divided into the phase of ciphertext data transmission path embedding and the phase of key distribution path embedding. The phase of ciphertext data transmission path embedding adopts multipath shared protection strategy with spectrum partitioning. And the phase of key distribution path embedding design a path splitting strategy when the key resources as well as spectrum resources are insufficient on a single path. Simulation results demonstrate that the SPSMP-VONE algorithm can effectively improve the spectrum utilization ratio and key utilization ratio by up to 12%.
With the development of optical networks integrated with quantum key distribution (QKD), the security of data transmission in virtual optical network has attracted increasing attention from researchers. In the existing security virtual optical network embedding (VONE) over elastic optical networks (EONs) integrated with QKD, the shortest path algorithm is used to reduce the consumption of security keys. In this paper, the concept and theory of computation and key distribution equilibrium (CKDE) is proposed. An integer linear programming model and a heuristic algorithm based on CKDE are presented for VONE over EONs integrated with QKD, where a node rank based on CKDE is introduced and the minimal element method is used to find a solution of VONE. Simulation experiments demonstrate that the proposed model and algorithm outperform existing approaches in terms of acceptance ratios, system revenues, and resource utilization. Specifically, the proposed algorithm achieves improvements of at least 35.1% in acceptance ratios and 49.6% in both system revenues and key resource utilizations compared to other heuristic algorithms.
Quantum Key Distribution (QKD) enables information-theoretic secure key exchange, but the deployment of large-scale QKD networks introduces new challenges related to routing, resource allocation, and security exposure in trusted-node-based architectures. In multipath QKD networks, the secret key rate can be partitioned and transmitted over multiple link-disjoint paths, so that an adversary must simultaneously compromise all paths to reconstruct the complete secret key. However, traffic is often equally distributed across the available disjoint paths, although such uniform partitioning may be suboptimal when candidate paths exhibit heterogeneous vulnerability levels. This paper proposes a security-aware optimization framework for QKD-enabled optical networks that determines a non-uniform multipath traffic partitioning strategy aimed at minimizing the expected amount of eavesdropped traffic. The proposed approach is formulated as a Mixed-Integer Linear Programming (MILP) model that integrates probabilistic secrecy metrics derived from trusted node compromise probabilities, a traffic vulnerability threshold that limits partial information exposure, and adaptive bandwidth squeezing protection to ensure service continuity under failure scenarios. The model jointly optimizes traffic allocation and excess key capacity, allowing the protection overhead to be dynamically determined according to security and resilience requirements. Numerical evaluations conducted on both a toy topology and the Pan-European network demonstrate that the proposed exposure-aware partitioning strategy significantly reduces the expected eavesdropped traffic compared to conventional equal-splitting approaches while maintaining resilience guarantees. These results highlight the potential of security-driven traffic engineering for the design of resilient and efficient multipath QKD networks.
Elastic Optical Network (EON) is a promising solution to address the high capacity, low latency, and flexibility requirements of the upcoming 5th-generation (5G) networks. Furthermore, Multi-Core Fibers (MCFs) and Space Division Multiplexing (SDM) technique can be utilized to overcome the capacity limitation of the conventional Single Mode Fibers (SMFs). On the other hand, Quantum Key Distribution (QKD) is an effective solution to address the security issues in 5G transport networks. In this paper, we investigate the performance of QKD over elastic optical networks with multi-core fibers and address the resource allocation problem for quantum and classical channels of QKD (QChs and CChs) and conventional data channels (DChs). To do so, we calculate the background noise caused by different noise sources and accordingly calculate the Secret Key Rate (SKR) in quantum channels. Then, we propose an Integer Linear Programming formulation and a heuristic algorithm to allocate network resources (spectrum, core, and links) to QChs, CChs, and DChs, with the objective of maximizing the secret key rate and minimizing the number of utilized frequency slots (FSs). Finally, we evaluate the proposed ILP and heuristic algorithm in terms of SKR and the number of utilized FSs. In our simulations, we consider core and metro topologies, fixed and distance adaptive launch power for classical signals, different fiber specifications, and different assumptions regarding the relative locations of quantum and classical channels in a multi-core fiber.
Quantum key distribution (QKD) is considered a secure solution for key distribution and applied in optical networks to overcome security issues by providing key services in different lightpaths. In optical networks, lightpaths in fibers can be used for the delivery of QKD due to their good transmission performance. Accordingly, optical networks secured by QKD have been regarded as an important paradigm, and survivability in this paradigm is an issue worthy of study. In this paper, we focus on the protection schemes for key services in optical networks secured by QKD. Specifically, in consistency with two characteristics of key services (i.e., the key-updating process and key-volume adaptive routing), two key-volume adaptive protection schemes (i.e., dedicated protection and shared protection) are proposed for the networks against link failures. In such scenarios, the designed key-protection threshold can alleviate the tight network resources caused by the key-updating process. Simulation work has been conducted to evaluate the performance of the proposed schemes in terms of blocking probability, resource utilization, and proportion of secret-key consumption with different key-protection thresholds and update periods. Numerical results show that the two proposed schemes are effective in providing protection. Furthermore, evaluating the impact of protection on network security verifies a trade-off that exists between how much protection can be provided for key services versus the overall security of the network, given a certain resource budget.
In quantum key distribution (QKD) networks, the quantum service channel (QSCh) is highly sensitive to link failures, as any interruption in the quantum channel can immediately halt key generation, and hence the transmission of secured data across optical networks. Hence, robust protection mechanisms are essential to ensure continuous secure key distribution. However, conventional protection approaches, such as dedicated protection and fixed-path routing, often suffer from low resource efficiency and poor adaptability to heterogeneous relay environments. To ensure both survivability and efficient resource allocation in QKD based optical networks, we propose a shared path protection scheme based on hybrid relays. In the proposed approach, K-candidate paths are computed for both the traditional data channel (TDCh) and QSCh, and the working path is selected using a weighted metric that considers both the hop-count and the security degree. To enhance resilience, the shared protection paths are established, allowing multiple backup paths to reuse network resources for connection requests. A connection request is accepted only if both the working and the protection paths are successfully reserved, thereby ensuring strong protection. The system incorporates joint allocation of wavelength and time-slot, and introduces a protection threshold to support shared use of backup resources. Simulation results show that the proposed method achieves lower blocking probability, while maintaining high wavelength and time-slot efficiency compared to the baseline methods in different networks.
Growing practicality and deployment of optical quantum key distribution (QKD) has renewed interest in information-theoretic secure (ITS) key exchange for future communication networks. Providing ITS keys as a service over existing optical network infrastructures is feasible, however it poses significant challenges, particularly due to limited access to large-scale QKD testbeds and the need to ensure reliability under network failures. To address this gap, this work presents a discrete-event QKD optical network simulator designed to study ITS key-as-a-service provisioning under fiber link failure conditions. The simulator integrates survivability and resource management concepts inspired by wavelength-division multiplexed optical networks. Using this framework, the performance of a time-slot key-rate-aware shared path protection (TSKRA-SPP) scheduling algorithm is evaluated in terms of throughput, failure tolerance, and quality of service (QoS). TSKRA-SPP provides high failure tolerance while keeping resource consumption significantly low compared to baseline Shared Path Protection (SPP) algoirthm. The results validates the proposed simulation framework to be an effective tool for analyzing resilient ITS key provisioning in QKD-enabled optical networks.