To ensure the security of information exchange in software-defined optical networks, quantum key distribution (QKD) based on quantum mechanics is introduced. However, the slow and valuable process of generating quantum key resources contradicts the high-speed data transmission requirements of optical networks. To address this issue, this paper proposes the CPSR-HQKDN scheme, which takes into account factors such as security requests, key demand, key residual, and key update rates for trusted and untrusted links. This approach improves resource utilization and service efficiency by optimizing the processing order of key requests. Moreover, the routing strategy dynamically adjusts based on the network resource environment, thereby increasing the success rate of key requests. Through simulation experiments comparing the performance of the CPSR-HQKDN routing scheme with existing schemes, it is observed that in high-concurrent scenarios, the CPSR-HQKDN routing scheme can improve the success rate of key requests by at least 5%.
To ensure the security of information exchange in software-defined optical networks, quantum key distribution (QKD) based on quantum mechanics is introduced. However, the slow and valuable process of generating quantum key resources contradicts the high-speed data transmission requirements of optical networks. To address this issue, this paper proposes the CPSR-HQKDN scheme, which takes into account factors such as security requests, key demand, key residual, and key update rates for trusted and untrusted links. This approach improves resource utilization and service efficiency by optimizing the processing order of key requests. Moreover, the routing strategy dynamically adjusts based on the network resource environment, thereby increasing the success rate of key requests. Through simulation experiments comparing the performance of the CPSR-HQKDN routing scheme with existing schemes, it is observed that in high-concurrent scenarios, the CPSR-HQKDN routing scheme can improve the success rate of key requests by at least 5%.
Quantum key distribution (QKD) is a technology that can resist the threat of quantum computers to existing conventional cryptographic protocols. However, due to the stringent requirements of the quantum key generation environment, the generated quantum keys are considered valuable, and the slow key generation rate conflicts with the high-speed data transmission in traditional optical networks. In this paper, for the QKD network with a trusted relay, which is mainly based on point-to-point quantum keys and has complex changes in network resources, we aim to allocate resources reasonably for data packet distribution. Firstly, we formulate a linear programming constraint model for the key resource allocation (KRA) problem based on the time-slot scheduling. Secondly, we propose a new scheduling scheme based on the graded key security requirements (GKSR) and a new micro-log key storage algorithm for effective storage and management of key resources. Finally, we propose a key resource consumption (KRC) routing optimization algorithm to properly allocate time slots, routes, and key resources. Simulation results show that the proposed scheme significantly improves the key distribution success rate and key resource utilization rate, among others.
Hybrid-trusted Quantum Key Distribution (QKD) networks face unique security challenges due to semi-trusted nodes. These nodes may introduce security threats such as man-in-the-middle attacks and key storage side-channel leakage. With the increasing complexity of QKD network architectures and expanding application scenarios, substantial divergences have emerged between user requirements for communication duration and cryptographic security demands. To address security challenges in hybrid-trusted QKD environments and provide differentiated services for users with varying requirements, this paper proposes a Service Requirement-based Hybrid-Trusted QKD Network (SRHT-QKDN) routing scheme. We propose a time-slot allocation model for QKD that employs time-slot resources as substitutes for key-generation resources in resource allocation processes. For sustained key distribution required by prolonged communications, the scheme implements two distinct time slot allocation algorithms: continuous-consistent and discrete-inconsistent allocation, enabling periodic quantum key updates. Concurrently, QKD requests are classified into three security levels, with corresponding routing strategies developed for each tier to achieve security service differentiation while maintaining routing success rates. Simulations conducted under four distinct operational conditions demonstrate that the SRHT-QKDN routing scheme not only effectively fulfills key continuity requirements but also achieves optimal overall performance in request success rate and security assurance, outperforming two benchmark routing schemes.
Quantum Key Distribution (QKD) is considered to be the ultimate solution to communication security. However, current QKD devices, especially quantum photon sources, are expensive, and they can generate secret keys only at a low rate. In this paper, we first consider homogeneous trusted-relay-based QKD networks where every request has the same amount of secret key requirement and every photon source has the same key distribution rate, and design an approach named RPSP to not only minimize the number of photon sources needed in a network to ensure at least one feasible relay path exists for any potential QKD requests but also save the time to complete a batch of QKD requests by jointly optimizing the routing of relay paths and the provisioning of photon sources to distribute secret keys. Then, we extend RPSP to RPSP-HN which can be applied to heterogeneous networks where requests have different secret key requirements and photon sources distribute keys at different rates. Furthermore, we also extend RPSP to RPSP-HY, which considers that some of the nodes in a network is untrusted. Compared with existing works, RPSP and its extensions focus on more practical scenarios where only some of the nodes are equipped with photon sources and they leverage optical switching to enable dynamic photon source provisioning such that we can utilize QKD devices more efficiently. Extensive simulations show that compared with baseline schemes, RPSP, RPSP-HN, and RPSP-HY can save up to 33%, 37%, and 25% of the time to complete a batch of QKD requests in homogeneous, heterogeneous, and hybrid QKD networks, respectively.
Quantum key distribution (QKD) is an encrypted communication technique based on the principles of quantum mechanics that ensures communication security by exploiting the properties of quantum states. Currently, the transmission efficiency of the QKD system is low. Trusted relay technology is used to solve this problem and achieve long-distance transmission. However, trusted relaying alone cannot decrypt the issues of poor link stability and the low utilization of key resources. To further optimize the system performance, we propose a dynamic routing algorithm. One of the improvement schemes includes the following: firstly, an adjustable-size quantum key pool (QKP) is designed, which can dynamically adjust the size of the refreshing pool according to the actual demand. Secondly, the utilization of key resources is improved by using the residual quantum key model to dynamically obtain the remaining key amount in the QKP and set the key amount threshold. We calculate the link-blocking probability and track the blocking intensity and blocking entry by combining the Poisson process, thus realizing the evaluation of the link stability. Finally, the number of remaining keys in the QKP and the link-blocking probability combine with the random wandering model as the basis of the route selection for the QKD dynamic routing algorithm to achieve efficient key path selection. We validated the algorithm by comparing it with other algorithms on the Mininet simulation platform, and the algorithm proved to have a better performance in terms of congestion avoidance, delay reduction, and improved QKD efficiency. This scheme provides a novel and efficient way to solve the problems in existing QKD systems. It effectively improves the transmission efficiency and strengthens the system’s security by dynamically obtaining the critical volume, accurately evaluating the link state, and selecting the optimal critical path.
Quantum Key Distribution (QKD) is considered to be an ultimate solution to communication security. However, current QKD devices, especially quantum photon sources, are expensive, and they can generate secret keys only at a low rate. In this paper, we design a system named RPSP for trusted relay-based QKD networks to not only minimize the number of photon sources needed in a network to ensure at least one feasible relay path exists for any potential QKD requests but also save the time to complete a batch of end-to-end QKD requests by jointly optimizing the routing of relay paths and the provisioning of photon sources along each relay path. Compared with existing works, RPSP focuses on a more practical scenario where only some of the nodes are equipped with photon sources and it leverages optical switching to enable dynamic photon source provisioning such that we can utilize such QKD devices in a more efficient way. Extensive simulations show that compared with baseline schemes, RPSP can save up to 87% of the photon sources needed in a trusted relay based QKD network, and 36% of the time to complete a batch of QKD requests.
With the continuous development of quantum computing technology, Quantum Key Distribution (QKD) is an important means of secure communication in the post-quantum era. However, the high cost of trusted routing relays in QKD networks has hindered its widespread adoption in power systems. Reducing costs is the key to the popularization of QKD in large-scale data grid scenarios. Therefore, this paper proposes a routing scheme for QKD network in a hybrid trusted environment. Our scheme is based on SDN architecture, utilizing the characteristics of QKD network in hybrid trusted environment, through prioritizing the selection of trusted paths (composed entirely of trusted quantum nodes) and backup selection of hybrid trusted paths (composed of both trusted and semi-trusted quantum nodes), implementing a unified dynamic routing strategy to obtain the optimal quantum routing path. Furthermore, by collecting topology information and real-time link status of the power grid, a calculation method for the number of paths and link costs is proposed to maximize load balancing in the network. Finally, the simulation results demonstrate that our scheme outperforms routing schemes relying solely on trusted quantum nodes for key distribution, as well as other cooperative routing schemes involving semi-trusted quantum nodes, in terms of success rate of distribution and load balancing.