基于量子隐形传态的量子保密通信方案

量子保密通信包括量子密钥分发、量子安全直接通信和量子秘密共享等主要形式.在量子密钥分发和秘密共享中,传输的是随机数而不是信息,要再经过一次经典通信才能完成信息的传输.在量子信道直接传输信息的量子通信形式是量子安全直接通信.基于量子隐形传态的量子通信(简称量子隐形传态通信)是否属于量子安全直接通信尚需解释.构造了一个量子隐形传态通信方案,给出了具体的操作步骤.与一般的量子隐形传态不同,量子隐形传态通信所传输的量子态是计算基矢态,大大简化了贝尔基测量和单粒子操作.分析结果表明,量子隐形传态通信等价于包含了全用型量子密钥分发和经典通信的复合过程,不是量子安全直接通信,其传输受到中间介质和距离的影响,所以不比量子密钥分发更有优势.将该方案与量子密钥分发、量子安全直接通信和经典一次性便笺密码方案进行对比,通过几个通信参数的比较给出各个方案的特点,还特别讨论了各方案在空间量子通信方面的特点.     

量子直接传态

把一个任意量子态在既有噪声又有窃听的信道下安全可靠地传输,是一个广泛而重要的问题.现在已有的方法是先传输大量的Einstein-Podolsky-Rosen(EPR)纠缠对,然后进行纠缠纯化,获得一对近似完美的纠缠对,再进行隐形传态或者远程态制备来传输量子态.本文给出一种直接安全传输量子态的方法,通过使用量子直接通信,...     

量子隐形传态

量子隐形传态是目前量子信息中人们关注的热门课题之一，它是量子信息理论的重要组成部分，也是量子计算的基础。文章阐述了标准量子隐形传态和概率量子隐形传态的基本理论以及EPR效应，Bell基测量等相关的概念，同时给出一种实现隐形传态的量子电路，并介绍了当前理论与实验的研究进展。     

利用三粒子纠缠态建立量子隐形传态网络的探讨

利用W态纠缠源可以产生三纠缠粒子，用这些相互纠缠的粒子作为量子信道，再辅以经典信道传送Bell基联合测量信息和von Neumann测量信息，便可实现量子隐形传态网络.基于上述思想，研究了三纠缠粒子量子隐形传态网络的物理基础，得到了基于三粒子W 关键词： 量子通信 量子隐形传态 W态')" href="#">W态     

量子隐形传态

量子隐形传态是目前量子信息中人们关注的热门课题之一,它是量子信息理论的重要组成部分,也是量子计算的基础。文章阐述了标准量子隐形传态和概率量子隐形传态的基本理论以及EPR效应,Bell基测量等相关的概念,同时给出一种实现隐形传态的量子电路,并介绍了当前理论与实验的研究进展。     

多方控制的量子安全直接通信协议的分析及改进

对一种多方控制的量子安全直接通信协议(WCZT协议)进行了安全性分析,并利用隐形传态给出了一种新的攻击方法.利用该攻击方法,接收方可以在没有征得任何控制方同意的情况下获得发送方的消息,因此该协议是不安全的.对该协议进行了改进,分析表明改进后的协议能够抵抗这种攻击,可以满足多方控制的量子安全直接通信的目的. 关键词： 隐形传态 单光子 多方控制 量子安全直接通信     

基于三粒子GHZ态的双向量子可控隐形传态

提出基于三粒子GHZ态的双向量子可控隐形传态方案.方案中,使用两个三粒子GHZ态作为量子通道.而根据在量子通道中发送者,接收者和控制者所拥有的粒子的不同以及所采用的测量基的不同,设计出了三方参与的双向可控量子隐形传态方案和四方参与的双向可控量子隐形传态方案.在方案中,Alice和Bob对所拥有的粒子做合适的投影测量,并将其测量结果通知对方和控制者.若控制者同意此次传态,则会对自己所拥有的粒子做投影测量,并将结果告知接收者.接收者根据发送者和控制者的测量信息,做出相对应的幺正操作来重建发送者的量子态.同时三方参与和四方参与的量子可控隐形传态方案提高了通信的安全性.     

利用Bell态实现量子隐形传态

量子隐形传态利用了量子的纠缠特性,在物理层实现了不可破译的量子密码通信.文章从信息论的角度描述了量子纠缠态的特性,给出了实现量子纠缠态的物理门线路;利用该量子纠缠态的量子线路,分析隐形传态的通信模型,给出了利用Bell态实现隐形传态的简单结构的量子线路,证明该量子线路是可行的,为进一步研究量子密码通信提供参考.     

量子隐形传态的新方案

提出一个量子隐形传态的新方案. 通过对一对压缩参数相同但相互独立的双模压缩真空态(1-2和3-4量子态系统)中的2-3系统施行粒子数-相位的联合测量,制备出另外两体系统(1-4系统)的纠缠态作为纠缠源,从而实现量子隐形传态. 关键词： 量子隐形传态 双模压缩真空态 纠缠态 粒子数-相位测量     

纠缠相干态的量子隐形传态

提出利用双模纠缠相干态作为量子信道，实现纠缠相干态量子隐形传态的方案. 分别在非正交的相干态表象和另一个由相干态构成的正交态表象对双模纠缠相干态的隐形传态进行具体分析. 发现在相干态表象，虽然只要线性光学元件就可以完成隐形传态，但成功的概率小于1/2，而在正交态表象，只要能分辨4个由相干态构成的Bell态，成功的概率就是1. 关键词： 隐形传态 纠缠相干态 纠缠相干态量子信道     

Threshold quantum secure direct communication without entanglement

For the first time, a threshold quantum secure direct communication (TQSDC) scheme is presented. Similar to the classical Shamir's secret sharing scheme, the sender makes n shares, S1, …, Sn of secret key K and each receiver keeps a share secretly. If the sender wants to send a secret message M to the receivers, he en-codes the information of K and M on a single photon sequence and sends it to one of the receivers. According to the secret shares, the t receivers sequentially per-form the corresponding unitary operations on the single photon sequence and ob-tain the secret message M. The shared shares may be reusable if it can be judged that there is no eavesdropper in line. We discuss that our protocol is feasible with current technology.     

Quantum secure direct communication and deterministic secure quantum communication

In this review article, we review the recent development of quantum secure direct communication (QSDC) and deterministic secure quantum communication (DSQC) which both are used to transmit secret message, including the criteria for QSDC, some interesting QSDC protocols, the DSQC protocols and QSDC network, etc. The difference between these two branches of quantum communication is that DSQC requires the two parties exchange at least one bit of classical information for reading out the message in each qubit, and QSDC does not. They are attractive because they are deterministic, in particular, the QSDC protocol is fully quantum mechanical. With sophisticated quantum technology in the future, the QSDC may become more and more popular. For ensuring the safety of QSDC with single photons and quantum information sharing of single qubit in a noisy channel, a quantum privacy amplification protocol has been proposed. It involves very simple CHC operations and reduces the information leakage to a negligible small level. Moreover, with the one-party quantum error correction, a relation has been established between classical linear codes and quantum one-party codes, hence it is convenient to transfer many good classical error correction codes to the quantum world. The one-party quantum error correction codes are especially designed for quantum dense coding and related QSDC protocols based on dense coding.      

量子直接通信

量子直接通信是量子通信中的一个重要分支, 它是一种不需要事先建立密钥而直接传输机密信息的新型通信模式. 本综述将介绍量子直接通信的基本原理, 回顾量子直接通信的发展历程, 从最早的高效量子直接通信协议、两步量子直接通信模型、量子一次一密直接通信模型等, 到抗噪声的量子直接通信模型以及基于单光子多自由度量子态及超纠缠态的量子直接通信模型, 最后介绍量子直接通信的研究现状并展望其发展未来.     

Measurement-device-independent quantum secure direct communication

Quantum secure direct communication(QSDC)is a unique technique,which supports the secure transmission of confidential information directly through a quantum channel without the need for a secret key and for ciphertext.Hence this secure communication protocol fundamentally differs from its conventional counterparts.In this article,we report the first measurement-deviceindependent(MDI)QSDC protocol relying on sequences of entangled photon pairs and single photons.Explicitly,it eliminates the security loopholes associated with the measurement device.Additionally,this MDI technique is capable of doubling the communication distance of its conventional counterpart operating without using our MDI technique.We also conceive a protocol associated with linear optical Bell-basis measurements,where only two of the four Bell-basis states could be measured.When the number of qubits in a sequence reduces to 1,the MDI-QSDC protocol degenerates to a deterministic MDI quantum key distribution protocol.     

Faithful quantum secure direct communication protocol against collective noise

An improved quantum secure direct communication (QSDC) protocol is proposed in this paper.Blocks of entangled photon pairs are transmitted in two steps in which secret messages are transmitted directly.The single logical qubits and unitary operations under decoherence free subspaces are presented and the generalized Bell states are constructed which are immune to the collective noise.Two steps of qubit transmission are used in this protocol to guarantee the security of communication.The security of the protocol against various attacks are discussed.     

Measurement-device-independent one-step quantum secure direct communication

The one-step quantum secure direct communication (QSDC) (Sci. Bull. 67, 367 (2022)) can effectively simplify QSDC's operation and reduce message loss. For enhancing its security under practical experimental condition, we propose two measurement-device-independent (MDI) one-step QSDC protocols, which can resist all possible attacks from imperfect measurement devices. In both protocols, the communication parties prepare identical polarization-spatial-mode two-photon hyperentangled states and construct the hyperentanglement channel by hyperentanglement swapping. The first MDI one-step QSDC protocol adopts the nonlinear-optical complete hyperentanglement Bell state measurement (HBSM) to construct the hyperentanglement channel, while the second protocol adopts the linear-optical partial HBSM. Then, the parties encode the photons in the polarization degree of freedom and send them to the third party for the hyperentanglement-assisted complete polarization Bell state measurement. Both protocols are unconditionally secure in theory. The simulation results show the MDI one-step QSDC protocol with complete HBSM attains the maximal communication distance of about 354 km. Our MDI one-step QSDC protocols may have potential applications in the future quantum secure communication field.     

基于cluster态的信道容量可控的可控量子安全直接通信方案

提出了一种基于五粒子cluster态的信道容量可控的可控量子安全直接通信方案.通信三方利用五粒子cluster态自身的粒子分布情况,结合诱骗光子,对粒子分别做Z基单粒子测量和Bell基测量,便可完成信道的第一次安全性检测.通信控制方Cindy通过对手中的粒子序列随机选用测量基(Z基或者X基)测量来决定信道容量,并通过经典信道公布结果.发送方Alice将要发送的信息以及校检信息用于对手中的粒子序列进行幺正操作编码,并插入诱骗光子后将编码后的粒子序列发给接收方Bob并通过经典信道告知其诱骗光子的位置信息.Bob接收到粒子序列后,按照经典信道Alice发送的信息,结合Cindy公布的信息,剔除诱骗光子后按照一定的规则对手中的两组粒子序列进行Bell基测量,便可解码完成第二次安全性检测以及得到Alice发送的信息.通过对五粒子cluster态的纠缠结构性质进行分析,阐明了五粒子cluster态在该方案中所表现出的特点的物理缘由.结果表明,只需变化测量基的规则和用于编码的粒子,可以将该方案推广成可控双向量子安全直接通信.     

多方控制的量子安全直接通信协议

基于单光子序列的顺序重排，提出了一种可应用于一些特殊的场景的多方控制的量子安全直接通信协议.协议中，接收方只有在得到所有控制方的同意之后，才能恢复出发送方的秘密消息.协议的安全性由量子不可克隆定理和单光子序列的秘密传输顺序所保证.此外，除了用于窃听检测的部分光子，所有的光子都用于编码秘密消息，而且协议的实现不需要使用纠缠态，该协议具有效率高和实现简单等特点. 关键词： 量子密码 量子安全直接通信 顺序重排 单光子