Efficient quantum private comparison protocol utilizing single photons and rotational encryption

As a branch of quantum secure multiparty computation,quantum private comparison is applied frequently in many fields,such as secret elections,private voting,and identification.A quantum private comparison protocol with higher efficiency and easier implementation is proposed in this paper.The private secrets are encoded as single polarized photons and then encrypted with a homomorphic rotational encryption method.Relying on this method and the circular transmission mode,we implement the multiplexing of photons,raising the efficiency of our protocol to 100%.Our protocol is easy to realize since only single photons,unitary operation,and single-particle measurement are introduced.Meanwhile,the analysis shows that our protocol is also correct and secure.

Efficient quantum private comparison protocol based on one direction discrete quantum walks on the circle

We propose an efficient quantum private comparison protocol firstly based on one direction quantum walks.With the help of one direction quantum walk,we develop a novel method that allows the semi-honest third party to set a flag to judge the comparing result,which improves the qubit efficiency and the maximum quantity of the participants’secret messages.Besides,our protocol can judge the size of the secret messages,not only equality.Furthermore,the quantum walks particle is disentangled in the initial state.It only requires a quantum walks operator to move,making our proposed protocol easy to implement and reducing the quantum resources.Through security analysis,we prove that our protocol can withstand well-known attacks and brute-force attacks.Analyses also reveal that our protocol is correct and practical.

Measure-Resend Semi-Quantum Private Comparison Scheme Using GHZ Class States

Quantum private comparison is an important topic in quantum cryptography.Recently,the idea of semi-quantumness has been often used in designing private comparison protocol,which allows some of the participants to remain classical.In this paper,we propose a semi quantum private comparison scheme based on Greenberge-Horne-Zeilinger(GHZ)class states,which allows two classical participants to compare the equality of their private secret with the help of a quantum third party(server).In the proposed protocol,server is semi-honest who will follow the protocol honestly,but he may try to learn additional information from the protocol execution.The classical participants’activities are restricted to either measuring a quantum state or reflecting it in the classical basis{0,1}.In addition,security and efficiency of the proposed schemes have been discussed.

Linear optical realization of unambiguous quantum state comparison

In this paper, we propose an experimental scheme for unambiguous quantum state comparison assisted by linear optical manipulations, twin-photons produced from parametric down-conversion, and postselection from the coincidence measurement. In this scheme the preparation of the general two mixed qubit states with arbitrary prior probabilities and the realization of the optimal POVMs for unambiguous quantum state comparison are presented. This proposal is feasible by current experimental technology, and may be used in single-qubit quantum fingerprinting.

Quantum private comparison of arbitrary single qubit states based on swap test

By using swap test,a quantum private comparison(QPC) protocol of arbitrary single qubit states with a semi-honest third party is proposed.The semi-honest third party(TP) is required to help two participants perform the comparison.She can record intermediate results and do some calculations in the whole process of the protocol execution,but she cannot conspire with any of participants.In the process of comparison,the TP cannot get two participants’ private information except the comparison results.According to the security analysis,the proposed protocol can resist both outsider attacks and participants’ attacks.Compared with the existing QPC protocols,the proposed one does not require any entanglement swapping technology,but it can compare two participants’ qubits by performing swap test,which is easier to implement with current technology.Meanwhile,the proposed protocol can compare secret integers.It encodes secret integers into the amplitude of quantum state rather than transfer them as binary representations,and the encoded quantum state is compared by performing the swap test.Additionally,the proposed QPC protocol is extended to the QPC of arbitrary single qubit states by using multi-qubit swap test.

New Quantum Private Comparison Using Hyperentangled GHZ State

In this paper,we propose a new protocol designed for quantum private comparison(QPC).This new protocol utilizes the hyperentanglement as the quantum resource and introduces a semi-honest third party(TP)to achieve the objective.This protocol’s quantum carrier is a hyperentangled three-photon GHZ state in 2 degrees of freedom(DOF),which could have 64 combinations.The TP can decide which combination to use based on the shared key information provided from a quantum key distribution(QKD)protocol.By doing so,the security of the protocol can be improved further.Decoy photon technology is also used as another means of security and checks if the transmission in the quantum channel is secure or not before sending the quantum carrier.The proposed protocol is proved to be able to fend off various kinds of eavesdropping attacks.In addition,the new QPC protocol also can compare secret inputs securely and efficiently.

A Comparison of the Concurrence and the Quantum Discord in a Two-Qubit System

The quantum correlation dynamics in an anisotropic Heisenberg XY Z model under decoherence are investigated with the use of concurrence C and quantum discord （QD）. There is a remarkable difference between the time evolution behaviors of these two correlation measures： there is a entanglement-sudden-death phenomenon in the concurrence while there is none in QD, which is valid for all of the initial states of this system, and the interval time of the entanglement death is found to be strongly dependent on the initial states and the parameters B and △. With the long-time limit the steady entanglement （SC） and steady quantum discord （SO, D） can be obtained. The magnitudes of SC and SQD are closely related to the parameters B and △, while the strength of the Dzyaloshinskii-Moriya interaction, D, has no influence. In addition, the effects of the parameters B and △ on SC and SQD display such different and complicated features that one cannot obtain a uniform law about them, thus we give an analytical explanation of this phenomenon. Lastly, it can be noted that the value of SC is not always larger than SQD, which is strongly dependent on the parameters B and △.

Efficient error estimation in quantum key distribution

In a quantum key distribution（QKD） system, the error rate needs to be estimated for determining the joint probability distribution between legitimate parties, and for improving the performance of key reconciliation. We propose an efficient error estimation scheme for QKD, which is called parity comparison method（PCM）. In the proposed method, the parity of a group of sifted keys is practically analysed to estimate the quantum bit error rate instead of using the traditional key sampling. From the simulation results, the proposed method evidently improves the accuracy and decreases revealed information in most realistic application situations.

Relativistic Reduction of the Electron-Nucleus Force in Bohr’s Hydrogen Atom and the Time of Electron Transition between the Neighbouring Quantum Energy Levels

The aim of the paper is to get an insight into the time interval of electron emission done between two neighbouring energy levels of the hydrogen atom. To this purpose, in the first step, the formulae of the special relativity are applied to demonstrate the conditions which can annihilate the electrostatic force acting between the nucleus and electron in the atom. This result is obtained when a suitable electron speed entering the Lorentz transformation is combined with the strength of the magnetic field acting normally to the electron orbit in the atom. In the next step, the Maxwell equation characterizing the electromotive force is applied to calculate the time interval connected with the change of the magnetic field necessary to produce the force. It is shown that the time interval obtained from the Maxwell equation, multiplied by the energy change of two neighbouring energy levels considered in the atom, does satisfy the Joule-Lenz formula associated with the quantum electron energy emission rate between the levels.

Faster than the Speed of Light Is a Quantum Phenomena

Classical Mechanics using Einstein’s theories of relativity places a limit on speed as the speed of light. Quantum Mechanics has no such limitation. To understand space accelerating faster than the speed of light and information being exchanged instantaneously between two entangled electrons separated by huge distances, one uses Planck’s length, Planck’s time, and Planck’s mass to indicate that space and time are discrete and therefore along with masses smaller than Planck’s mass are Quantum Mechanical in nature. Faster than the speed of light c = 3 × 108 m/s is a classical effect only in dimensions of space lower than our 3-D Universe, but it is a Quantum effect in all dimensions of space. Because space can oscillate sending out ripples from the source, it is the medium used for transporting light waves and gravity waves.

基于半量子安全直接通信的量子拍卖协议

针对现有量子密封拍卖协议中存在的报价隐私保护不够、恶意竞标者与第三方共谋等问题,提出了一种基于半量子安全直接通信的量子密封投标拍卖协议。该协议采用半量子安全直接通信,通信时拍卖方仅需拥有测量和反射粒子的能力;通过对投标方报价的保序加密,实现对报价的隐私保护;利用隐私比较,在无第三方参与的情况下,拍卖方也能比较保序加密后的报价信息。理论分析表明面对截获-重发、受控非门(CNOT)、相位反转、共谋等攻击时,所提出协议仍具有较高的安全性,且与同类型量子拍卖协议相比,新协议通信效率不受投标人数的影响。

基于Bell态纠缠交换的量子私密比较方案

提出了一种新的量子私密比较方案,该方案以Bell态为量子资源,在不泄露用户私密信息的前提下,利用Bell测量和纠缠变换实现对用户的信息相等与否的比对。第三方(TP)制备Bell态和诱饵单光子,在传送粒子过程中,TP插入诱饵单光子,通过经典信道的讨论保证了方案的安全性。用户双方不需要做任何幺正变换,只需执行Bell测量,随后将自己的私密信息加密后发送给第三方。第三方通过简单的计算就可以实现两比特经典信息的比对.整个过程中所涉及到的三方都无法得知他人的私密信息,只能得到比对结果.最后,由TP宣布比较结果。此外,也验证了方案的正确性。

从哥本哈根解释到退相干解释——量子力学解释的建构与比较

量子力学解释是对量子理论的扩展,必须体现量子理论语义上的一致性。正统的哥本哈根解释、最低限度的系综解释、本体论解释、多世界解释、模态解释、退相干解释,它们的解释力强弱与附加性要求不同,从两者之间的张力比较这些解释,既是整体科学知识的需要,也是理论语义上一致性的需要。

量子密钥分发误码协调算法分析

误码消除是量子密钥分发过程的关键技术之一。分析了奇偶-汉明单向函数纠错算法的原理,给出了对原始量子密钥进行误码协调的步骤及表达式,对这种算法的纠错能力进行了理论和实验分析。结果显示,当原始密钥误码率为11%时,利用该纠错技术能够完全消除误码,且最终密钥生成效率与密钥的原始误码率直接相关。

周期性信号之间的相位量子特征及其应用

针对周期性信号之间的普遍规律性,分析了等效鉴相频率和相位量子的概念.周期性信号除自身的变化规律外,周期性信号之间相互作用和联系的基础是相位量子,它揭示了周期性信号普遍联系的本质.实验证明相位量子是相互作用的周期性信号之间不可分割的基本个体,以相位量子为基础的测量、比对和控制能实现任意频率信号之间的直接相位比对.相位量子在主动型氢原子钟锁相环线路改造中简化了传输线路,减少了相位噪声引入,提高了性能。

几种多步辛演化法的对比(英文)

提出了一种新的确定多步是子时间演化辛算法系数的方法，并比较了现有的三种确定系数的方法．发现对于三步辛算法，这里提出的方法在小时间间隔下更精确，而文献中从对称性出发确定的系数的稳定性区间更宽．

新型量子霍尔电阻样品计量应用研究

采用AsGa砷化镓系材料研制了多种结构的新型量子霍尔电阻样品,介绍了该样品的特点及应用领域。使用常温电流比较仪和低温电流比较仪,用过渡比对法对新型的量子霍尔电阻与标准量子霍尔电阻样品进行了双重测量比对验证,在实验室内测量结果的相对偏差小于4×10^-8,验证了新型的量子霍尔电阻样品和测量系统的准确度满足当前计量应用需求。

我国的1V及10V约瑟夫森量子电压基准装置

文章描述了我国量子电压基准的建立、发展、现状和所取得的成果,以及与国际计量局进行基准关键比对的情况。

C与S构图评估技术的比较研究

引用Yue等学者关于2种概念图——自由构图与选择构图(简称C与S)评估技术等价性的实验研究,用总正确得分、单命题得分、命题选择和结构复杂性4个变量,以《量子力学》为载体对C与S技术进行了定性和定量的比较研究.实验结果显示,2种构建概念图技术的效果不同,|Z|=1.98,P<0.05,因此,C技术比S技术更能捕捉学生构建知识结构的情况,而S技术在构图的制作上易于C技术;就评价工具而言,C技术更适于形成性评估,而S技术较适于终结性评估.构图结果表明,当今大学生在知识组织、知识构建、知识表征特别是知识创新方面有待提高.

共线和非共线模式下单光子探测器定标比对实验研究

采用相关光子法定标单光子探测器的量子效率对提高光学载荷的辐射定标准确度具有重要意义.利用355nm连续激光泵浦BBO晶体产生Ⅰ类自发参量下转换,在共线和非共线两种相位匹配模式下分别测量了单光子探测器雪崩光电二极管在736nm波段的量子效率.结果表明,共线和非共线两种模式测量结果的合成不确定度分别为0.71%和0.39%,相对偏差均优于0.4%,这两种模式都可以定标探测器量子效率,且具有很好的一致性.最后比较了两种模式定标探测器量子效率的优缺点,该研究为以后利用相关光子法对遥感器进行辐射定标提供了晶体相位匹配模式选择的依据.