A scheme is proposed for quantum information splitting of a two-qubit Bell state by using a four-qubit entangled state as a quantum channel. In the scenario, it is supposed that there are three legitimate parties, say Alice, Bob and Charlie. Alice is the sender of quantum information. Bob and Charlie are two agents. Alice first performs GHZ state measurement and tells Bob and Charlie the measurement results via a classical channel. It is impossible for Bob to reconstruct the original state with local operations unless help is obtained from Charlie. If Charlie allows Bob to reconstruct the original state information, he needs to perform a single-qubit measurement and tell Bob the measurement result. Using the measurement results from Alice and Charlie, Bob can reconstruct the original state. We also consider the problem of security attacks. This protocol is considered to be secure.
针对监测区域中移动目标的跟踪问题,提出基于Mobicast的动态分簇组播路由方案,簇头节点负责对节点入簇的审查和管理,并根据网络拓扑环境和节点自身状况的改变而动态调整分簇策略,最大限度地提高组播效率和网络性能。通过调整节点入簇门限条件,使得只有性能最优的节点才能参于Mobicast会话;引入自感知技术,动态评估当前组播服务质量(quality of service,QoS)需求;利用矩阵编码和线性规划技术实时选择最佳分簇策略。分析和仿真结果表明,与现有Mobicast路由协议相比,本方案具有较低的平均时延和能耗,以及良好的QoS性能。
