Improving the security of multiparty quantum secret sharing based on the improved Boström-Felbinger protocol

In a recent paper [Z.J. Zhang et al., Opt. Commun. 269 (2007) 418], a protocol of multiparty quantum secret sharing was presented. We study the security of this protocol and found that it is not secure for a dishonest agent Charlie, who can illegally elicit half of Alice’s secret message by himself. Finally a feasible improvement of this quantum secret sharing protocol is proposed.     

Eavesdropping on the improved three-party quantum secret sharing protocol

Lin et al. [Song Lin, Fei Gao, Qiao-yan Wen, Fu-chen Zhu, Opt. Commun. 281 (2008) 4553] pointed out that the multiparty quantum secret sharing protocol [Zhan-jun Zhang, Gan Gao, Xin Wang, Lian-fang Han, Shou-hua Shi, Opt. Commun. 269 (2007) 418] is not secure and proposed an improved three-party quantum secret sharing protocol. In this paper, we study the security of the improved three-party quantum secret sharing protocol and find that it is still not secure. Finally, a further improved three-party quantum secret sharing protocol is proposed.     

Multiparty quantum secret sharing based on the improved Boström-Felbinger protocol

Based on the famous quantum secure direct communication protocol (i.e., the Boström-Felbinger protocol) [Phys. Rev. Lett. 89 (2002) 187902] and its improvements, we propose a scheme of multiparty quantum secret sharing of classical messages (QSSCM), in which no subset of all the classical message receivers is sufficient to extract the sender’s secret classical messages but all the parties cooperate together. Then we take advantage of this multiparty QSSCM scheme to establish a scheme of multiparty secret sharing of quantum information (SSQI), in which the unknown quantum state in the sender’s qubit can be reconstructed in one receiver’s qubit if and only if all the quantum information receivers collaborate together.     

Cryptanalysis of multiparty quantum secret sharing with Bell states and Bell measurements

The security of multiparty quantum secret sharing with Bell states and Bell measurements [R.H. Shi et al., Opt. Commun. 283 (2010) 2476] is analyzed. It is shown that the first agent and the last one can gain access to the dealer's secret if they collaborate in this protocol. Therefore, this protocol does not satisfy the security requirement of quantum secret sharing.     

Differential Phase Shift Quantum Secret Sharing Using a Twin Field with Asymmetric Source Intensities

As an essential application of quantum mechanics in classical cryptography, quantum secret sharing has become an indispensable component of quantum internet. Recently, a differential phase shift quantum secret sharing protocol using a twin field has been proposed to break the linear rate-distance boundary. However, this original protocol has a poor performance over channels with asymmetric transmittances. To make it more practical, we present a differential phase shift quantum secret sharing protocol with asymmetric source intensities and give the security proof of our protocol against individual attacks. Taking finite-key effects into account, our asymmetric protocol can theoretically obtain the key rate two orders of magnitude higher than that of the original protocol when the difference in length between Alice’s channel and Bob’s is fixed at 14 km. Moreover, our protocol can provide a high key rate even when the difference is quite large and has great robustness against finite-key effects. Therefore, our work is meaningful for the real-life applications of quantum secret sharing.     

Multiparty quantum secret sharing of secure direct communication using single photons

We propose a protocol for multiparty quantum secret sharing of secure direct communication using single photons. In this protocol, random phase shift operations instead of some special discrete unitary operations used usually are employed to realize the sharing controls. The security of this protocol with respect to various kinds of attacks is discussed. Due to the complete randomicity of the phase shift characterizing the unitary operations, the security of secret sharing is therefore enhanced.     

Improving the security of multiparty quantum secret sharing against an attack with a fake signal

We come up with a special attack strategy to the multiparty quantum secret sharing protocol [Z.J. Zhang, Y. Li, Z.X. Man, Phys. Rev. A 71 (2005) 044301]. Using fake signal and Bell measurement, the agent Bob who generates the initial signals can elicit Alice's secret message. With little modification, our strategy also works for an improved version of this protocol. At last, a further improvement of the multiparty quantum secret sharing protocol is proposed.     

Expandable quantum key distribution networks based on secret bits comparison

A scheme of quantum network based on multiuser differential phase shift quantum key distribution system (DPS-QKD) is proposed. In this quantum network, arbitrary two users can achieve secret bits sharing by point-to-multipoint quantum key distribution and secret bits comparison. A protocol of secret bits sharing between arbitrary two users is presented. This network can implement secret bits distribution over 200 km with higher key generation rate by today's technologies. In theory, the capacity of user numbers in this network is unlimited. Hence, our proposed quantum network can serve for a metropolitan QKD network. A wide area QKD network can be constructed with this metropolitan QKD network.     

Improvement on ‘Cryptanalysis and Improvement of a Multiparty Quantum Direct Secret Sharing of Classical Messages with Bell States and Bell Measurements’

Recently, Liu (Int J Theor Phys: pp.1–6, 2018) pointed out that Song et al.’s multiparty quantum direct secret sharing protocol (Int J Theor Phys: 57, 1559, 2018) suffers from several attacks and then an improved quantum direct secret sharing protocol was hence proposed. However, this study shows that Liu’s protocol still suffers from an intercept-resend attack. To solve this problem, a modification is proposed here.

     

High-Dimensional Circular Quantum Secret Sharing Using Orbital Angular Momentum

Quantum secret sharing is to distribute secret message securely between multi-parties. Here exploiting orbital angular momentum (OAM) state of single photons as the information carrier, we propose a high-dimensional circular quantum secret sharing protocol which increases the channel capacity largely. In the proposed protocol, the secret message is split into two parts, and each encoded on the OAM state of single photons. The security of the protocol is guaranteed by the laws of non-cloning theorem. And the secret messages could not be recovered except that the two receivers collaborated with each other. Moreover, the proposed protocol could be extended into high-level quantum systems, and the enhanced security could be achieved.     

Threshold Quantum Secret Sharing of Secure Direct Communication

We propose a （L, n）-threshold quantum secret sharing protocol of secure direct communication following some ideas of Zhang＇s protocol [Phys. Lett. A 342 （2005） 60] and Tokunaga et al.＇s protocol [Phys. Rev. A 71 （2005） 012314]. The sender distributes the classical secret shares to his or her n agents and each agent owns a secret share in advance. The sender＇s secure direct communication message can be extracted by an agent subset by collaboration in such a way that at least t or more agents can obtain the secret message with the mutual assistances but any t - 1 or fewer agents cannot. In contrast to the previous multiparty quantum secret sharing protocols in which the sender＇s secret message can be recovered only if all the agents collaborate, our protocol is more practical and more flexible.     

基于显微物镜的表面等离子体共振

对孙莹等提出的利用Greenberger-Horne-Zeilinger态实现的可控量子秘密共享协议Alice-Bob信道和Alice-Charlie信道窃听检测的虚警概率进行分析,指出该协议窃听检测虚警概率不为0的原因在于窃听检测测量基选择的随机性.然后,提出一种改进的利用Greenberger-Horne-Zeilinger态实现的可控量子秘密共享协议,以确定性的方式选择窃听检测的测量基.理论分析表明,改进的利用Greenberger-Horne-Zeilinger态实现的可控量子秘密共享协议不仅能够以原协议2倍的概率发现任何一个内部不可信方,从而具有更高的安全性,而且窃听检测虚警概率达到0.     

可控量子秘密共享协议窃听检测虚警概率分析

对孙莹等提出的利用Greenberger-Horne-Zeilinger态实现的可控量子秘密共享协议Alice-Bob信道和Alice-Charlie信道窃听检测的虚警概率进行分析,指出该协议窃听检测虚警概率不为0的原因在于窃听检测测量基选择的随机性.然后,提出一种改进的利用Greenberger-HorneZeilinger态实现的可控量子秘密共享协议,以确定性的方式选择窃听检测的测量基.理论分析表明,改进的利用Greenberger-Horne-Zeilinger态实现的可控量子秘密共享协议不仅能够以原协议2倍的概率发现任何一个内部不可信方,从而具有更高的安全性,而且窃听检测虚警概率达到0.     

Quantum secret sharing protocol using modulated doubly entangled photons

In this paper, we propose a quantum secret sharing protocol utilizing polarization modulated doubly entangled photon pairs. The measurement devices are constructed. By modulating the polarizations of entangled photons, the boss could encode secret information on the initial state and share the photons with different members to realize the secret sharing process. This protocol shows the security against intercept-resend attack and dishonest member cheating. The generalized quantum secret sharing protocol is also discussed.     

Quantum Secret Sharing Using GHZ-Like State

This paper presents a simple and novel quantum secret sharing schemeusing GHZ-like state. The characteristics of the GHZ-like state areused to develop the quantum secret sharing scheme. In contrast withthe other GHZ-based QSS protocols with the same assumptions, the proposed protocol provides the best quantum bit efficiency.     

Quantum secret sharing without entanglement

After analysing the main quantum secret sharing protocol based on the entanglement states, we propose an idea to directly encode the qubit of quantum key distributions, and then present a quantum secret sharing scheme where only product states are employed. As entanglement, especially the inaccessible multi-entangled state, is not necessary in the present quantum secret sharing protocol, it may be more applicable when the number of the parties of secret sharing is large. Its theoretic efficiency is also doubled to approach 100%.     

n-Bit Quantum Secret Sharing Protocol Using Quantum Secure Direct Communication

International Journal of Theoretical Physics - The proposed quantum secret sharing protocol in this article conveys n bit secret messages from the sender to the n receivers making use of a secure...     

A Multi-party Quantum Key Agreement Protocol Based on Shamir’s Secret Sharing

Quantum networks can extend the advantages of quantum key distribution protocols to more than two remote participants. Based on Shamir threshold secret sharing scheme, a new quantum key agreement protocol on a quantum network with any number of participants is proposed. First, each participant and distributor negotiate a sub-secret key using a kind of quantum key distribution protocol, and then each of these participants, as distributor, shares these sub-secret keys with other participants using Shamir threshold secret sharing scheme. Furthermore, each participant combines all these shared sub-secret keys and his own sub-secret key in sequence to form secret key, and sends the hash function values of this secret key to the master distributor to authenticate, finally they obtain the security key. Our scheme is practical and secure, and it can also prevent fraudulent from participants.

     

Multiparty quantum secret sharing based on Bell measurement

A multiparty quantum secret sharing scheme based on Bell measurement is proposed and analyzed. In this scheme, all agents are not required to prepare entangled states or perform any local unitary operation. The security of the protocol is also analyzed. It is shown that any eavesdropper will introduce errors invariably and be detected if he tries to steal information about Trent’s secret. Moreover, because no classical bit needs to be transmitted except those for detection, the total efficiency of the scheme approaches to 100%.     

Dynamic quantum secret sharing protocol based on two-particle transform of Bell states

To solve the problems of updating sub-secrets or secrets as well as adding or deleting agents in the quantum secret sharing protocol, we propose a two-particle transform of Bell states, and consequently present a novel dynamic quantum secret sharing protocol. The new protocol can not only resist some typical attacks, but also be more efficient than the existing protocols. Furthermore, we take advantage of the protocol to establish the dynamic secret sharing of a quantum state protocol for two-particle maximum entangled states.