基于连续变量量子通信的地铁量子调度网络研究

Metro dispatching network using continuous-variable quantum communication

地铁调度网络作为地铁运营系统的重要组成部分,是实现地铁系统中列车调度、实时监控和紧急通信等作业顺利进行的基础。针对地铁调度网络中调度信息的安全传输问题,提出一种基于量子通信技术的地铁调度信息的加密过程,以期实现调度信息的无条件安全传输,从而提升地铁系统中列车调度、实时监控和紧急通信等业务的安全性和保密性,保障广大乘客人身安全。考虑成本、数据规模以及量子系统与现有网络和器件的融合性,拟在地铁调度网络中采用增量部署和星型组网的方式开展基于连续变量的量子通信,分析其在集体攻击下的安全性。以深圳地铁10号线为例,设计一种基于CV-QKD技术的地铁量子调度网络。基于实际线路数据,计算部分站点之间通信的安全密钥率。仿真结果表明,连续变量量子通信能满足深圳地铁10号线全线的数据加密需求,并且有能力实现更远通信距离的调度信息安全传输。在通信距离较短的情况下,系统可使用较大的发送端信号方差或在接收端使用外差检测来实现更高的安全密钥率。相反,在长距离通信的情况下,接收端使用零差检测是性价比更高的选择。

As an important part of metro operation system,the metro dispatching network is the basis for the smooth operation of train dispatching,real-time monitoring,emergency communication and so on.To prove the security of information in the subway dispatching network,a solution with quantum communication,which is based on the basic principles of quantum mechanics,was proposed in this paper.The proposed solution can realize unconditional security,demonstrating the privacy of train dispatch,real-time monitoring,and emergency communication,as well as the safety of passengers.Considering the cost,data scale,and compatibility of the quantum system with existing networks and devices,the continuous-variable protocol with incremental deployment and star networking is used.The continuous-variable protocol is introduced,and its ability against collective attacks is also analyzed.A metro quantum dispatching network based on CV-QKD was designed for 10th Line of Shenzhen Metro,and the secret key rate was calculated using data of the line.Numerical analysis shows that the proposed protocol can meet the requirement of the 10th Line,and even longer lines.Besides,the secret key rate is optimized by using larger variance and heterodyne detector in short-distance case.When the transmission distance is longer,homodyne detection is a more cost-effective choice.