受控循环远程态制备

为了解决多方量子通信问题,首先提出一种构造十粒子纠缠态的方法,并籍此构造出一个3◢n◣+1粒子纠缠态。其次,以十粒子纠缠态为量子信道,提出一个三方受控循环远程制备协议。该协议在监察者David的控制下,Alice能为Bob远程制备一个任意单粒子态,Bob能够在Charlie处远程制备一个任意单粒子态,Charlie也能为Alice远程制备任意单粒子态。进一步,借助3◢n◣+1粒子纠缠态,将此循环协议推广到任意◢n◣方受控循环远程态制备情形。在远程态制备过程中,每个发送者充分利用各自掌握的信息和前馈策略来构造恰当的测量基,通过经典通信和局域操作,就能成功实现任意单粒子态的远程制备。     

通过五粒子信道的非对称双向量子信息传输

利用一个五粒子团簇态为信道,分别提出了三个关于二粒子态和单粒子态的双向受控量子信息传输协议。在第一个协议中,通过引入辅助粒子,实施受控非门运算和Bell态测量,Alice能把二粒子未知态传送给Bob,同时Bob也能把单粒子未知态传送给Alice。在第二个方案中,通过引入辅助粒子、巧妙构造正交基和执行单粒子投影测量,Alice能帮助Bob远程地制备二粒子已知态,同时Bob也能帮助Alice远程地制备单粒子已知态。由于他们充分利用了前馈策略去构造测量基,制备任务能够完美完成。在第三个方案中,结合前两个方案的特点,Alice能成功将二粒子未知态传送给Bob,Bob也完美地在Alice处制备单粒子已知态。上述三个方案离开监控者的允许是不能实现的。     

以任意高维纠缠态为量子信道的受控隐形传态

目的是利用高维量子纠缠态为量子信道，讨论未知单粒子态的受控隐形传输问题。以三维量子纠缠态为信道，提出一个二维任意单粒子态的受控隐形传输协议。提出了以任意[d]-维量子纠缠态为量子信道，[t]-维任意单粒子态的隐形传输协议[(t相似文献   

利用纠缠态实现任意N粒子量子态的秘密共享

针对量子秘密共享的量子态局限于最大纠缠态的问题,提出一种实现任意N位量子态的秘密共享方案。该方案使用纠缠态作为量子信道,首先发送方对粒子进行Bell基测量,然后接收方Bob或Charlie使用单粒子测量,最后参与者根据Alice和单粒子测量得到的结果,选用合适的联合幺正变换对量子态进行相应的变换,这样可以实现任意N粒子量子态的秘密共享。该方案能够抵御外部窃听者和内部不诚实参与者的攻击,安全性分析表明此方案是安全的。     

传送任意三粒子纠缠态的三个方案

提出传送任意三粒子纠缠态的三个方案,分别是利用三对二粒子纠缠态、单个三粒子最大纠缠态和利用两个EPR态作为量子通道实现三粒子纠缠态的传送。通过发送者(Alice)对需传送的三粒子纠缠态与属于自己的纠缠对中的粒子分别进行适当的Bell基测量,然后把结果通过经典通道告诉接收者(Bob),接收者根据这些信息对自己拥有的三粒子进行相应的联合幺正变换,就可以实现一定概率的隐形传态。这些方案都可以推广至N个粒子纠缠态的传送。     

基于多参数测量的双向受控隐形传态

融合了双向隐形传态、受控隐形传态、概率隐形传态及多参数测量思想,提出了一个新的双向受控概率隐形传态协议。在该协议中,以五粒子非最大纠缠团簇态为信道,发送者采用多参数通用测量,接收者引入辅助粒子,并在控制者的允许下,利用测量信息施行适当酉变换,就能以一定概率同时交换他们的量子态。分析了成功概率（经典耗费）与量子纠缠参数及测量参数间的依赖关系,说明了该协议可以根据量子信道的参数来调整多参数测量的参数,达到调节成功概率或经典耗费,满足真实世界中多种不同需求的目的。此外,该协议是经典双向受控隐形传态的推广。     

以最大slice态为信道的受控量子远程控制

利用三量子最大slice态作为量子信道,提出了单量子酉算子的受控远程执行的两个协议.首先,利用双向量子隐形传态(BQST),给出了一个任意单量子酉算子的受控隐形传输方案.结果 表明,通过非最大纠缠信道,发送者能够在遥远的接受者的量子系统上远程地执行一个任意单量子酉算子.如果发送者和控制者对各自量子执行恰当的投影测量,那...     

9-量子团簇态信道的非对称双向量子信息传输

利用一个9-量子团簇态为信道,分别提出了三个关于二量子态和三量子态的双向量子信息传输协议。在第一个协议中,Alice能把三量子a1、a2和a3的未知态传送给Bob,Bob能把二量子b1和b2的未知态传送给Alice。Alice采用特殊三粒子态测量基,使得方案简化了一半。在第二个协议中,Alice在远方的Bob处制备三粒子a1、a2和a3的已知态,同时Bob也能在Alice处制备二量子b1和b2的已知态。由于他们充分利用了前馈测量策略,制备任务能够完美完成。在第三个协议中,利用前两个协议的优点,Alice能成功将三量子a1、a2和a3的未知态传送给Bob,Bob也完美地在Alice处制备二量子b1和b2的已知态。     

基于Bell态纠缠交换的量子盲签名方案

基于量子纠缠交换理论,提出一种基于Bell态纠缠交换的量子盲签名方案。消息拥有者Alice将待签名消息发送给盲签名者Charlie,Charlie根据双方共享的量子密钥对消息进行盲化签名,加密后发送给消息验证者Bob。Bob收到盲化签名后,根据他与Charlie共享的量子密钥对签名进行验证。利用量子纠缠特性,实现了消息对签名者Charlie的盲化性。基于量子密钥分发和一次一密技术,保证了签名过程的绝对安全性。     

可控量子远程通信方案的研究

针对一般可控量子远程通信方案能防止外部窃听,但无法有效防止冒充攻击这一安全缺陷,提出一种具备身份认证功能的可控量子远程通信方案。可信任第三方Charlie利用纠缠交换对接收者Bob进行身份认证,在确定Bob的合法身份并将消息反馈给发送者Alice后,Alice再传送量子信息。该方案利用身份认证能有效防止冒充攻击,并能够增强量子信息传送的正确性和安全性。     

Three-party remote state preparation schemes based on entanglement

By exploiting the entanglement correlation in quantum mechanics, two three-party remote state preparation (RSP) schemes are proposed. One is three-party remote preparation of a single-particle quantum state, and the other is three-party remote preparation of a two-particle entangled state. In the proposed schemes, the sender Alice knows the quantum states to be prepared, while the receivers Bob and Charlie do not know the quantum states; Alice performs measurement and unitary operations on her own particles with two three-particle GHZ states as the quantum channel. According to Alice’s measurement results, Bob and Charlie measure their own particles on the corresponding quantum measurement bases and perform unitary operations on the corresponding particles to reconstruct the quantum states, respectively. Compared with multiparty joint remote preparation and two-party RSP of a quantum state, the proposed schemes realize quantum multicast communication successfully, which enables Bob and Charlie to obtain the prepared quantum states simultaneously in the case of just knowing Alice’s measurement results, while Bob and Charlie do not know each other’s prepared quantum states. It is shown that only three classical bits are required for the two proposed RSP schemes when Bob and Alice introduce an auxiliary particle, respectively, and the proposed schemes are secure after the quantum channel authentication.     

Bidirectional controlled quantum teleportation and secure direct communication using five-qubit entangled state

A scheme is presented to implement bidirectional controlled quantum teleportation (QT) by using a five-qubit entangled state as a quantum channel, where Alice may transmit an arbitrary single qubit state called qubit A to Bob and at the same time, Bob may also transmit an arbitrary single qubit state called qubit B to Alice via the control of the supervisor Charlie. Based on our channel, we explicitly show how the bidirectional controlled QT protocol works. By using this bidirectional controlled teleportation, espcially, a bidirectional controlled quantum secure direct communication (QSDC) protocol, i.e., the so-called controlled quantum dialogue, is further investigated. Under the situation of insuring the security of the quantum channel, Alice (Bob) encodes a secret message directly on a sequence of qubit states and transmits them to Bob (Alice) supervised by Charlie. Especially, the qubits carrying the secret message do not need to be transmitted in quantum channel. At last, we show this QSDC scheme may be determinate and secure.     

Deterministic controlled bidirectional remote state preparation via a six-qubit entangled state

In this paper, we presented a controlled bidirectional remote state preparation scheme which used the six-qubit entangled state as quantum channel. In our scheme, Alice and Bob can prepare simultaneously an arbitrary single-qubit state in each other’s place with the control of the supervisor Charlie. The success probability for our scheme reaches unit. Furthermore, we analyze the expression of quantum channel for controlled bidirectional remote state preparation. Finally, we discuss the security of our scheme, the detailed security analysis shows that the supervisor Charlie’s control can greatly improve the security of our scheme.

     

Cluster态的量子签名方案

提出一种利用Cluster state纠缠态实现的量子签名方案。该方案中用Cluster态作为量子信道,每一组量子比特串分别分发给消息拥有和签名者Alice、公证人TA、验签名者Bob。加载消息的方法是Alice在TA规定量子比特串序列下,分别对拥有的量子比特对的第一个量子比特进行幺正变换操作而进行。对拥有的量子比特对进行的Bell测量结果是消息的签名。Bob对拥有的对应的两个量子比特对进行Bell测量来验证签名,但要得到公证人TA对其约束才能完成。Cluster state纠缠态在纠缠特性、局域操作保真性和安全性有较好的性能。     

Controlled teleportation against uncooperation of part of supervisors

We study the teleportation of an unknown quantum state from a sender (Alice) to a receiver (Bob) via the control of many supervisors (Charlie 1, Charlie 2, . . .) in a network. It has been shown that such a task can be achieved by distributing a GHZ-type entangled state among the participants in advance. In the protocols with GHZ-type entanglement channel, the achievement of teleportation between Alice and Bob is conditioned on the cooperation of all the supervisors. In other words, if anyone of the supervisors does not cooperate, the teleportation will fails. In this paper, we introduce another kind of controlled teleportaton protocol with other types of entangled states acting as the quantum channel, in which the teleportation between Alice and Bob can be realized with high degree of endurance against uncooperation of part of supervisors.      

Bidirectional controlled teleportation by using nine-qubit entangled state in noisy environments

A theoretical scheme is proposed to implement bidirectional quantum controlled teleportation (BQCT) by using a nine-qubit entangled state as a quantum channel, where Alice may transmit an arbitrary two-qubit state called qubits \(A_1\) and \(A_2\) to Bob; and at the same time, Bob may also transmit an arbitrary two-qubit state called qubits \(B_1\) and \(B_2\) to Alice via the control of the supervisor Charlie. Based on our channel, we explicitly show how the bidirectional quantum controlled teleportation protocol works. And we show this bidirectional quantum controlled teleportation scheme may be determinate and secure. Taking the amplitude-damping noise and the phase-damping noise as typical noisy channels, we analytically derive the fidelities of the BQCT process and show that the fidelities in these two cases only depend on the amplitude parameter of the initial state and the decoherence noisy rate.     

Multi-party quantum secret sharing with the single-particle quantum state to encode the information

We present a three-party quantum secret sharing (QSS) scheme via the entangled Greenberger–Horne–Zeilinger state. In this scheme, the sender Alice encodes her arbitrary secret information by means of preparing a single-particle quantum state. The agent Bob obtains his shared information according to his hobby, while Charlie can easily calculate his shared information. The proposed scheme is secure. It is shown that even a dishonest agent, who may avoid the security checking, cannot obtain any useful information. Moreover, we further investigate the multi-party QSS scheme which allows most agents to predetermine their information.