A multiparty quantum secret sharing (QSS) protocol is proposed by using swapping quantum entanglement of Bell states. The secret messages are imposed on Bell states by local unitary operations. The secret messages are split into several parts and each part is distributed to a party so that no action of a subset of all the parties but their entire cooperation is able to read out the secret messages. In addition, the dense coding is used in this protocol to achieve a high efficiency. The security of the present multiparty QSS against eavesdropping has been analyzed and confirmed even in a noisy quantum channel.
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。
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。
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 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。
Multiparty quantum communication is an important branch of quantum networks. It enables private information transmission with information-theoretic security among legitimate parties. We propose a sender-controlled measurement-device-independent multiparty quantum communication protocol. The sender Alice divides a private message into several parts and delivers them to different receivers for secret sharing with imperfect measurement devices and untrusted ancillary nodes. Furthermore, Alice acts as an active controller and checks the security of quantum channels and the reliability of each rece…
In order to avoid the risk of information leakage during the information mutual transmission between two authorized participants, i.e., Alice and Bob, a quantum dialogue protocol based on the entanglement swapping between any two Bell states and the shared secret Bell state is proposed. The proposed protocol integrates the ideas of block transmission, two-step transmission and unitary operation encoding together using the Bell states as the information carriers. Besides the entanglement swapping between any two Bell states, a shared secret Bell state is also used to overcome the information le…
In this paper, a novel multi-party quantum private comparison (MQPC) protocol with a semi-honest third party (TP) is proposed based on the entanglement swapping of d-level cat states and d-level Bell states. Here, TP is allowed to misbehave on his own but will not conspire with any party. In our protocol, n parties employ unitary operations to encode their private secrets and can compare the equality of their private secrets within one time execution of the protocol. Our protocol can withstand both the outside attacks and the participant attacks on the condition that none of the QKD methods is…
This study proposes a multiparty mediated quantum secret sharing (MQSS) protocol that allows n restricted quantum users to share a secret via the assistance of a dishonest third-party (TP) with full quantum capabilities. Under the premise that a restricted quantum user can only perform the Hadamard transformation and the Z-basis measurement, the proposed MQSS protocol has addressed two common challenges in the existing semi-quantum secret sharing protocols: (1) the dealer must have full quantum capability, and (2) the classical users must equip with the wavelength quantum filter and the photon…
Quantum secret sharing (QSS) is essential for multiparty quantum communication, which is one of cornerstones in the future quantum internet. However, a linear rate-distance limitation severely constrains the secure key rate and transmission distance of QSS. Here, we present a practical QSS protocol among three participants based on the differential phase shift scheme and twin field ideas for the solution of high-efficiency multiparty communication task. In contrast to formerly proposed differential phase shift QSS protocol, our protocol can break the linear rate-distance bound, theoretically i…
A quantum steganography protocol with large payload is proposed, based on dense coding and entanglement swapping of GHZ states. Its super quantum channel is formed by building up the hidden channel within the original quantum secure direct communication (QSDC) scheme. Based on the original QSDC, secrets messages are transmitted by integrating dense coding of GHZ states and entanglement swapping of GHZ states. Its capacity of super quantum channel achieves six bits per round covert communication, much higher than the previous quantum steganography protocols. Its imperceptibility is good, since …
Eavesdropping on the improved three-party quantum secret sharing protocol
Lin等[S. Lin，F. Gao，Q.- y. Wen，F.- C. Zhu，Opt. Commun. 281（2008）4553]指出多方量子秘密共享协议[Z.- j. Zhang，G. Gao、X.王湖，澳-地F.汉，S.- H. Shi，Opt. Commun. 269（2007）418]是不安全的，提出了一种改进的三方量子秘密共享协议。本文研究了改进的三方量子秘密共享协议的安全性，发现它仍然是不安全的。最后，提出了一个进一步改进的三方量子秘密共享协议。
In this paper, a multi-party quantum private comparison (MQPC) scheme is suggested based on entanglement swapping of Bell entangled states within d-level quantum system, which can accomplish the equality comparison of secret binary sequences from n users via one execution of scheme. Detailed security analysis shows that both the outside attack and the participant attack are ineffective. The suggested scheme needn't establish a private key among n users beforehand through the quantum key distribution (QKD) method to encrypt the secret binary sequences. Compared with previous MQPC scheme based o…
Multiparty quantum communication provides delightful applications including quantum cryptographic communication and quantum secret sharing. Measurement-Device-Independent (MDI) quantum communication based on the Greenberg-Horne-Zeilinger (GHZ) state measurement provides a practical way to implement multiparty quantum communication. With the standard spatially localized GHZ state measurement, however, information can be imbalanced among the communication parties that can cause significant problems in multiparty cryptographic communication. Here, we propose an equitable multiparty quantum commun…
Recently, Liu W et al. proposed a two-party quantum private comparison (QPC) protocol using entanglement swapping of Bell entangled state (Commun. Theor. Phys. 57(2012)583-588). Subsequently, Liu W J et al. pointed out that in Liu W et al.'s protocol, the TP can extract the two users' secret inputs without being detected by launching the Bell-basis measurement attack, and suggested the corresponding improvement to mend this loophole (Commun. Theor. Phys. 62(2014)210-214). In this paper, we first point out the information leakage problem toward TP existing in both of the above two protocols, an…
We introduce a class of two-level multi-particle Greenberger-Horne-Zeilinger (GHZ) states, and study entanglement swapping between two systems for Bell states and the class of GHZ states in qubit systems, respectively. We give the formulas for the entanglement swapping of Bell states and GHZ states in any number of qubit systems. We further consider entanglement swapping between any number of Bell states and between any number of the introduced GHZ states, and propose a series of entanglement swapping schemes in a detailed way. We illustrate the applications of such schemes in quantum informat…
