Asymmetric multi-party quantum state sharing of an arbitrary m-qubit state

We present a scheme for asymmetric multi-party quantum state sharing of an arbitrary m-qubit state with n agents. The sender Alice first shares m − 1 Bell states and one n + 1-particle Greenberger–Horne–Zeilinger state with n agents, where the agent Bob, who is designated to recover the original m-qubit state, just keeps m particles and other agents (all controllers) n − 1 particles, that is, each controller only holds one particle in hand. Subsequently, Alice performs m Bell-basis measurements on her 2m particles and each controller only need take a single-particle measurement on his particle with the basis X. Finally, Bob can recover the original m-qubit state with the corresponding local unitary operations according to Alice and all controllers’ measurement results. Its intrinsic efficiency for qubits approaches 100%, and the total efficiency really approaches the maximal value, which is higher than those of the known symmetric schemes.     

An efficient scheme for multi-party quantum state sharing of an arbitrary multi-qubit state with one GHZ channel

We present an innovative and extremely efficient scheme to share an arbitrary multi-qubit state between n agents with only 1 GHZ channel under control of m agents in a network. Compared with existing ones in this literature, our scheme requires less communication resources, least qubits and only three physical favorable simple operations (single-qubit measurement, Bell-basis measurement and CNOT gate operations) are included, leading to a higher overall efficiency.     

Multi-party quantum state sharing of an arbitrary two-qubit state with Bell states

We present a new scheme for sharing an arbitrary two-qubit quantum state with n agents. In our scheme, the sender Alice first shares n Einsein-Podolsky-Rosen (EPR) pairs in Bell states with n agents. After setting up the secure quantum channel, Alice first applies (n − 2) Controlled-Not (CNOT) gate operations, and then performs two Bell-state measurements and (n − 2) single-particle measurements (n >2). In addition, all controllers only hold one particle in their hands, respectively, and thus they only need to perform a single-particle measurement on the respective particle with the basis {|0?, |1?}{{{vert}0rangle, {vert}1rangle}}. Compared with other schemes with Bell states, our scheme needs less qubits as the quantum resources and exchanges less classical information, and thus obtains higher total efficiency.     

Multi-party quantum state sharing of an arbitrary multi-qubit state via \chi -type entangled states

By using the \(\chi \) -type entangled states, a novel scheme for multi-party quantum state sharing (MQSTS) of an arbitrary multi-qubit state is investigated. It is shown that the MQSTS scheme can be faithfully realized by performing appropriate Bell state measurements, Z basis measurements and local unitary operations, rather than multi-qubit entanglement or multi-particle joint measurements. Thus, our MQSTS scheme is more convenient in a practical application than some previous schemes. Furthermore, its intrinsic efficiency for qubits approaches 100 %, and the total efficiency really approaches the maximal value, which is higher than those of the previous MQSTS schemes. Finally, we analyze the security from the views of participant attack and outside attack in detail.     

Quantum state sharing of an arbitrary four-qubit GHZ-type state by using a four-qubit cluster state

We demonstrate that a four-qubit cluster state can be used to realize the deterministic quantum state sharing (QSTS) of an arbitrary four-qubit GHZ-type state among three parties by introducing three ancillary qubits and performing three controlled-NOT operations. In our scheme, any one of the two agents has the ability to reconstruct the original state if he/she collaborates with the other one, whilst individual agent obtains no information.     

Quantum state sharing of an arbitrary three-qubit state by using three sets of W-class states

A new application of the W-class state for quantum state sharing (QSTS) of an arbitrary three-qubit state with a certain probability is presented explicitly. We show that three sets of W-class states can be used to realize the QSTS of an arbitrary three-qubit state involving Bell-state measurement, single-qubit measurement and one high dimensional unitary operation. The performance demonstrates that our scheme can considerably reduce the difficulty of physical implementation.     

Quantum information splitting of an arbitrary three-qubit state by using two four-qubit cluster states

A new application of the four-qubit cluster state is investigated for quantum information splitting (QIS) of an arbitrary three-qubit state. Muralidharan and Panigrahi (Phys Rev A 78:062333, 2008) argued that a four-qubit cluster state is impossible for QIS of an arbitrary two-qubit state. In this paper, we demonstrate that two four-qubit cluster states can be used to realize the deterministic QIS of an arbitrary three-qubit state by performing only the Bell-state measurements. Our scheme considered here is secure against certain eavesdropping attacks.     

基于团簇态的量子秘密共享方案

提出了一个基于团簇态的量子秘密共享方案,发送者通过Pauli操作将经典秘密信息编码在团簇态上进行分发,接收者通过联合测量实现秘密共享。协议插入EPR对作为诱骗态以防止窃听,通过安全性分析证明本协议是安全的,可以抵抗截获-测量、截获-重发和纠缠-测量攻击。此外,协议传输一个四粒子团簇态可以共享四个经典比特信息,量子比特效率达到100%。     

基于Cluster态的n位量子态共享方案

为达到n位量子态秘密共享的目的,建立四粒子Cluster态和五粒子Cluster态的量子信道,提出两个量子秘密共享方案。Cluster态与其它纠缠态(W态和GHZ态)不同,相比最大纠缠态,其在某些方面具有很好的稳定性,且实验容易制备。两个方案均只用两次bell测量。第一个方案中,重构者只需对所持有的粒子进行相应的幺正变换即可;第二个方案引入一个辅助粒子最后实施CNOT操作就可恢复原始秘密。对于任意量子态的共享方案,都可以根据需要将最终量子态通过相应的量子线路得到所需要恢复的初始量子态。在安全性方面,分析外部攻击和内部攻击,得到所提出的方案是安全的。     

Highly efficient remote preparation of an arbitrary three-qubit state via a four-qubit cluster state and an EPR state

An efficient protocol for remotely preparing an arbitrary three-qubit state is devised with a four-qubit cluster state and an Einstein–Podolsky–Rosen state as the shared quantum resource. Using an appropriate set of eight-qubit mutually orthogonal measurement basis, the remote three-qubit preparation is successfully completed with the probability of ${\frac{1}{8}}$ in general case. Then to achieve our concerns of improving the probability of this protocol, some special ensembles of three-qubit states are minutely investigated. As a result, it is shown that the total probability of the RSP protocol, in these particular cases, can be improved to ${\frac{1}{4}}$ and ${\frac{1}{2}}$ , respectively, or even that the RSP protocol can be realized with unit success probability.     

Arbitrated quantum signature scheme based on cluster states

Cluster states can be exploited for some tasks such as topological one-way computation, quantum error correction, teleportation and dense coding. In this paper, we investigate and propose an arbitrated quantum signature scheme with cluster states. The cluster states are used for quantum key distribution and quantum signature. The proposed scheme can achieve an efficiency of 100 %. Finally, we also discuss its security against various attacks.     

Controlled quantum dialogue using cluster states

This paper presents a new controlled quantum dialogue (CQD) protocol based on the cluster entangled states. The security analyses indicate that the proposed scheme is secure under not only various well-known attacks but also the collusive attack, where the participants may collude to communicate without the controller’s permission. Compared to a previous CQD scheme, which is also robust against the conspiracy attack, the proposed protocol is more efficient in both the qubit efficiency and the hardware requirement.     

一种高效实用的秘密分存方案

秘密分存机制在密钥管理、数据安全等方面有非常广泛的应用,是现代密码学领域中一个非常重要的分支,也是网络信息安全方向一个重要的研究内容。本文针对校园网中教务管理的实际应用,提出一种高效实用的2人秘密分存方案,并详细介绍其原理和实现方法。该方案算法简单方便,容易编码实现,并结合对称密钥、公开密钥加密机制保护原始秘密,可为增强类似系统的安全性提供参考。     

三态纠缠的可控的量子秘密共享协议

提出由3个节点组成的星型量子网络中,基于三态纠缠的可控的量子秘密共享协议。在协议中,3个节点S₁、S₂、S₃共享2N个GHZ-like states,发送编码序列,利用可控制的状态参量α,将测量结果的联合计算共享密钥。理论分析证明,该协议对于外在的窃听者Eve和内在的窃听者都具有很高的安全性。如果存在窃听者,则必然发现,从而保证了共享量子密钥的安全性。     

Efficient joint remote preparation of an arbitrary two-qubit state via cluster and cluster-type states

In this paper, we present a possible improvement of the successful probability of joint remote state preparation via cluster states following some ideals from probabilistic joint remote state preparation (Wang et al. in Opt Commun, 284:5835, 2011). The success probability can be improved from $1/4$ to 1 via the same quantum entangled channel by adding some classical information and performing some unitary operations. Moreover, we also discussed the scheme for joint remote preparation via cluster-type states. Compared with other schemes, our schemes have the advantage of having high successful probability for joint preparation of an arbitrary two-qubit state via cluster states and cluster-type states.     

两个基于四粒子纠缠态的量子秘密共享方案

本文分别基于四粒子Cluster态和一个非对称的四粒子纠缠态,提出两个量子秘密共享的方案,其中共享的秘密是未知的单粒子态。秘密的发送者需要对手中的粒子进行Bell基测量,协助者需要对手中的粒子进行测量或者实施幺正操作,最后接收者通过对手中的粒子进行相应的幺正变换或者受控非门操作,就可以重构原始秘密。通过分析表明,任何一个代理者在其他两方协助下是可以恢复秘密的,所以我所提出的方案是高效且安全可靠的。     

An efficient Boolean based multi-secret image sharing scheme

The purpose of this paper is to develop an algorithm for sharing k secret images to n participants in such a way that each participant gets a single share image by encoding all k images. Any qualified subgroup of t : t ≤ n of those n participants can reconstruct the k_ith secret image only by combining their share images if they are qualified to reconstruct the k_ith secret image. Most of the existing literature solves this problem for the cases where t =?2 or t = n making it a very restrictive scheme. In this article, we aim to design a multi-secret image sharing scheme based on XOR operation where t is not restricted to be 2 or n. We have used n random matrices of the same size as the secret image size as private share to generate r (where r is the number of qualified subgroups) share images as public share using XOR operations. The proposed scheme is computationally lightweight and lossless due to XOR operation only. It does not involve any pixel expansion. The experimental results with a very low correlation coefficient between share and secret images confirm that share image does not reveal anything about secret image. The scheme is secure against differential attack as a higher value of Number of Changing Pixel rate (NPCR) confirms that. The current proposal is based on a general access structure, and hence any secret image can be reconstructed by a qualified group of t or more shares where t need not be 2 or n only.

     

An efficient quantum blind digital signature scheme

Recently, many quantum digital signature (QDS) schemes have been proposed to authenticate the integration of a message. However, these quantum signature schemes just consider the situation for bit messages, and the signing-verifying of one-bit modality. So, their signature efficiency is very low. In this paper, we propose a scheme based on an application of Fibonacci-, Lucas- and Fibonacci-Lucas matrix coding to quantum digital signatures based on a recently proposed quantum key distribution (QKD) system. Our scheme can sign a large number of digital messages every time. Moreover, these special matrices provide a method to verify the integration of information received by the participants, to authenticate the identity of the participants, and to improve the efficiency for signing-verifying. Therefore, our signature scheme is more practical than the existing schemes.