基于受控隐形传态[Phys. Rev. A \textbf{72}，02338（2005）]的思想，我们提出了一个对称的多方量子态共享方案，其中任意一个$m$ -量子比特态与$m$ Greenberger-Horne-Zeilinger态共享.发送方Alice对她的$2m$粒子进行$m$ Bell态测量，而控制方只需要对它们的光子进行单光子乘积测量，而不需要Bell态测量，这使得该方案比后者更方便。而且它不需要各方对光子执行受控非门来重建未知的$m$ -量子比特状态，并且它是最佳的，因为它对量子比特的效率接近最大值。
英文摘要：
We present a scheme for symmetric multiparty quantum state sharing of an arbitrary $m$-qubit state with $m$ Greenberger-Horne-Zeilinger states following some ideas from the controlled teleportation [Phys. Rev. A \textbf{72}, 02338 (2005)]. The sender Alice performs $m$ Bell-state measurements on her $2m$ particles and the controllers need only to take some single-photon product measurements on their photons independently, not Bell-state measurements, which makes this scheme more convenient than the latter. Also it does not require the parties to perform a controlled-NOT gate on the photons for reconstructing the unknown $m$-qubit state and it is an optimal one as its efficiency for qubits approaches the maximal value.
Comment on "A special attack on the multiparty quantum secret sharing of secure direct communication using single photons"
在这篇评论中，我们表明，特殊攻击[S.- J. Qin，F. Gao，Q.- Y. Wen，F.- C. Zhu，Opt. Commun. 281（2008）5472.]，其声称能够通过随机相移操作获得使用单光子的安全直接通信的多方量子秘密共享的协议的所有传输的秘密消息比特值，失败了。此外，一类类似的攻击也被证明是无法提取的秘密消息。
Based on the two-step protocol [Phys. Rev. A68(03)042317], we propose a $(n,n)$-threshold multiparty quantum secret sharing protocol of secure direct communication. In our protocol only all the sharers collaborate can the sender's secure direct communication message be extracted. We show a variant version of this protocol based on the variant two-step protocol. This variant version can considerably reduce the realization difficulty in experiment. In contrast to the use of multi-particle GHZ states in the case that the sharer number is larger than 3, the use and identification of Bell states ar…
Improving the security of multiparty quantum secret splitting and quantum state sharing
Deng { \rm et al.}最近提出了一个利用有序的$N$ Einstein-Podolsky-Rosen（EPR）对和Bell态测量的多方量子秘密分裂（MQSS）协议。[Phys. Lett. A 354（2006）190]。对协议的安全性进行了分析，发现该协议对除代理人Bob采用拦截重发攻击外的任何窃听者都是安全的。Bob可以在不被发现的情况下单独获得Alice的所有信息。我们还提出了一个改进的MQSS协议。
Comment on "Cryptanalysis and improvement of multiparty quantum secret sharing schemes"
我们表明，使用王等人攻击[T.- y.王，Q.- y. Wen，F. Gao，S. Lin，F.- C. Zhu，Phys. Lett. A 373（2008）65]，在Zhang等人的QSSCM方案[Z.- j. Zhang，G. Gao、X.王湖，澳-地f Han，S.- H. Shi，Opt. Commun. 269（2007）418]。从某种意义上说，Wang等人的攻击对Zhang等人的QSSCM方案是不成功的。
Improving the security of multiparty quantum secret sharing against Trojan horse attack
分析了Zhang，Li和Man [Phys. Rev. A \textbf{71}，044301（2005）]提出的多方量子秘密共享（MQSS）协议的安全性，发现该协议对于除准备量子信号的代理人Bob之外的任何窃听者都是安全的，因为他可以利用特洛伊木马攻击量子通信.也就是说，Bob用多光子信号替换了单光子信号，而另一个代理Charlie无法发现这种欺骗，因为她在光子从老板Alice那里跑回来之前没有测量光子，这表明这种MQSS协议对Bob来说并不安全。最后，我们提出了一个可能的改进MQSS协议的安全性与两个单光子测量和六个酉操作。
A scheme for secure multiparty quantum summation was proposed by Run-hau Shi et al.,(SCIENTIFIC REPORTS, 6:19655, DOI:10.1038/srep19655). IBM Corporation has released a superconductivity based 5-qubit quantum computer named "Quantum Experience" and placed it on "cloud". In this paper we take advantage of the online availability of this real quantum processor(ibmqx2) and carry out the above protocol that has never been experimentally demonstrated earlier. Here, we set up experiments for secure quantum summation of one-qubit secret states . Besides, we propose a protocol for square and cubic sum…
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Consider the problem: Alice wishes to send the same key to $n-1$ users (Bob, Carol,. . . , Nathan), while preventing eavesdropper Eve from acquiring information without being detected. The problem has no solution in the classical cryptography but in quantum telecommunication there are some codes to solve the problem. In the paper \cite{zengetall}, Guo-Jyun Zeng, Kuan-Hung Chen, Zhe-Hua Chang, Yu-Shan Yang, and Yao-Hsin Chou from one side and Cabello in \cite{cabello} from other side, used Hadamard gates, Pauli gates in providing the quantum communication code for two-partity telecommunication …
Monogamy is a nonclassical property that limits the distribution of quantum correlation among subparts of a multiparty system. We show that monogamy scores for different quantum correlation measures are bounded above by functions of genuine multipartite entanglement for a large majority of pure multiqubit states. The bound is universal for all three-qubit pure states. We derive necessary conditions to characterize the states that violate the bound, which can also be observed by numerical simulation for a small set of states, generated Haar uniformly. The results indicate that genuine multipart…
