A better routing scheme becomes more significant with the quantum key distribution network developing. This paper makes use of pre-relay, parallel work and shortest path first strategy and proposes a hierarchical routing scheme with the perspective of parallel processing on wide-area quantum key distribution network based on trusted relay. Then the paper proposes the hierarchical routing algorithm. Through theoretical analysis and experiment result, it shows that the hierarchical routing scheme can effectively shorten the key transmission time and improve the efficiency of key transmission, which is better than the single layer routing scheme.
A better routing scheme becomes more significant with the quantum key distribution network developing. This paper makes use of pre-relay, parallel work and shortest path first strategy and proposes a hierarchical routing scheme with the perspective of parallel processing on wide-area quantum key distribution network based on trusted relay. Then the paper proposes the hierarchical routing algorithm. Through theoretical analysis and experiment result, it shows that the hierarchical routing scheme can effectively shorten the key transmission time and improve the efficiency of key transmission, which is better than the single layer routing scheme.
In order to explore the solution of the problems of the short of knowledge and immature theoretical research about large scale,specifically wide-area,quantum key distribution network research,the structure model,the secret key model and the active model of the trusted relaying quantum key distribution network were proposed from the viewpoints of structure,inner secret key relationship and working principle respectively for the trusted relaying quantum key distribution network which is the only real practical one so far.Firstly,from the viewpoint of system theory,the quantum key distribution network was divided into five layers according to the basic principle of key relaying based on the existing structure model.The constitution of each layer and the relationship between them were explained in detail.Secondly,from the viewpoint of information theory,the quantum key distribution network was abstracted as a key information graph according to the key sharing relationship among all nodes and the node and edge were formally defined.Therefore,the secret key information in the five layers quantum key distribution network could be explained by the graph theory in details.Lastly,from the viewpoint of the cybernetics, the key distribution process was resolved into two basic parts of key relationship establishment and secrete key generation,then the works of the quantum key distribution network could be explained by the development of key information graphs.The analysis showed that the proposed quantum key distribution network model can achieve the goal of hierarchical,parallel and pipelining key distribution,and can ensure the security of key distribution,which establishes the foundation for the future theoretical and technology research.
ABSTRACT. Quantum key distribution (QKD) network develops rapidly in recent years. In order to improve the efficiency and security of quantum key distribution, this paper analyzes the advantages and disadvantages of single-path and multi-path quantum key distribution and proposes a multi-path quantum key distribution scheme. This scheme includes two aspects which are path equalization priority strategy and the No-public nodes strategy. The priority of the chosen path is based on the path bandwidth utilization, the number of routing hops and quantum keys stored in the trusted nodes. The no-public nodes strategy selects multiple key distribution paths without public nodes. The scheme can reduce the risk of path blocking and the consumption of quantum keys, improve the efficiency and security of QKD. Finally, this scheme is analyzed and verified.
Aiming at the problem that the quantum key distribution strategy in the existing QKD network based on key relay cannot meet the routing requirements in the hybrid network environment, we analyzes the routing characteristics of the classic-quantum hybrid network and proposes the corresponding routing requirements, and then designs the quantum key distribution strategy based on ant colony algorithm. The ant colony algorithm is used to analyze the execution cost of ants to search for the best global quantum key distribution, which improves the key routing efficiency in the classical and quantum hybrid network environment. Simulation results show that the proposed scheme has the advantages of fast convergence of routing update, small delay of quantum key distribution and more balanced network load.
The long-distance transmission of quantum secret key is a challenge for quantum communication. As far as the current relay technology is concerned, the trusted relay technology is a more practical scheme. However, the trusted relay technology requires every relay node to be trusted, but in practical applications, the security of some relay nodes cannot be guaranteed. How to overcome the security problem of trusted relay technology and realize the security key distribution of remote quantum network has become a new problem. Therefore, in this paper, a method of quantum key distribution in ring network is proposed under the condition of the coexistence of trusted and untrusted repeaters, and proposes a partially-trusted based routing algorithm (PT-RA). This scheme effectively solves the security problem of key distribution in ring backbone network. And simulation results show that PT-RA can significantly improve key distribution success rate compared with the original trusted relay technology.
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.
The point-to-point quantum key distribution (QKD) system is limited by the transmission distance. So, the wide area QKD network with multiple endpoints is the research focus of this study. The relay-node scenario and key relay protocols provide the solutions to the QKD network. The early key relay protocols require the relay nodes to be reliable. Once the relay nodes become compromised, the whole network is insecure. In this paper, we extend the chain structure of the public-XOR(exclusive OR)-key scheme with two endpoints to the complex network with multiple endpoints. The relay nodes in our scheme do not need encryption actions, decryption actions, or storage XOR keys, which simplifies the system compared with other key distribution schemes based on trusted relay nodes. Our scheme not only improves the practical performance and simplifies the system’s complexity, but it also ensures that the security is not reduced. Specifically, we rigorously demonstrate that an eavesdropper can never access the key shared by the users of the network as long as the process of generating XOR keys and destroying the original keys is secure. In addition, we discuss the information leakage of the practical QKD network from the perspective of the unicity distance.