基于预报单光子源的BB84诱惑态量子密钥分配研究

结合预报单光子源的量子密钥分配系统模型,介绍了三种典型的BB84诱惑态方案：主动诱惑态方案,被动诱惑态方案以及主动诱惑态思想和被动诱惑态思想相结合的方案。结合数值仿真深入分析了三种方案在性能、实现难度等方面的优缺点。结论表明被动诱惑态思想可以进一步提高BB84诱惑态方案的密钥生成效率;BB84被动诱惑态方案（AYKI方案）由于无需主动制备诱惑态,所以实现最为简单,密钥分配速度快,且方案性能趋近于无穷诱惑态的理论极限值;主动诱惑态思想和被动诱惑态思想相结合的方案性能虽然稍优于AYKI方案,但是改善空间很小。     

基于测量设备无关协议的量子身份认证方案

借助测量设备无关量子密钥分配协议的安全性,提出了测量设备无关的量子身份认证协议。在此协议下,认证中心和认证方以共享密钥加密认证信息和认证密钥,将其发送至第三方进行贝尔态测量以提取安全的认证信息,实现认证中心对认证方有效认证,并更新共享密钥。分析协议性能显示,系统在不同攻击下认证过程是安全且有效的。     

Four-state reference-frame-independent quantum key distribution using heralded pair-coherent sources with source flaws

We propose a four-state reference-frame-independent quantum key distribution (RFI-QKD) protocol with the heralded pair-coherent source (HPCS). We investigate the performance of the proposed protocol and simulation results show that our protocol can achieve a high key generation rate in long-distance transmission, taking source flaws and statistical fluctuations into consideration. Although fewer states are used, this protocol not only has a higher key generation rate at the same transmission distance but also a longer transmission distance with the same secure communication compared with the original six-state RFI-QKD protocol using the weak coherent source (WCS).     

Passive measurement-device-independent quantum key distribution with orbital angular momentum and pulse position modulation

Based on the orbital angular momentum and pulse position modulation, we present a novel passive measurement-device-independent quantum key distribution (MDI-QKD) scheme with the two-mode source. Combining with the tight bounds of the yield and error rate of single-photon pairs given in our paper, we conduct performance analysis on the scheme with heralded single-photon source. The numerical simulations show that the performance of our scheme is significantly superior to the traditional MDI-QKD in the error rate, key generation rate and secure transmission distance, since the application of orbital angular momentum and pulse position modulation can exclude the basis-dependent flaw and increase the information content for each single photon. Moreover, the performance is improved with the rise of the frame length. Therefore, our scheme, without intensity modulation, avoids the source side channels and enhances the key generation rate. It has greatly utility value in the MDI-QKD setups.     

Research on measurement-device-independent quantum key distribution based on an air-water channel

A measurement-device-independent quantum key distribution (MDI-QKD) method with an air-water channel is researched. In this method, the underwater vehicle and satellite are the legitimate parties, and the third party is at the air-water interface in order to simplify the unilateral quantum channel to water or air. Considering the condition that both unilateral transmission distance and transmission loss coefficient are unequal, a perfect model of the asymmetric channel is built. The influence of asymmetric channel on system loss tolerance and secure transmission distance is analyzed. The simulation results show that with the increase of the channel’s asymmetric degree, the system loss tolerance will descend, one transmission distance will be reduced while the other will be increased. When the asymmetric coefficient of channel is between 0.068 and 0.171, MDI-QKD can satisfy the demand of QKD with an air-water channel, namely the underwater transmission distance and atmospheric transmission distance are not less than 60 m and 12 km, respectively.     

基于挑战-应答机制的量子密钥分发协议

基于BB84协议,利用挑战-应答机制,提出了一种量子密钥分发协议。发送方Alice和接收方Bob通过安全信道共享三个不同的Hash函数( , 和 ),以及随机比特串 。在每次密钥分发时,Alice产生随机比特串 （挑战信息）和 （密钥）,结合 和 ,基于BB84协议产生光子串 ;Alice将 和 发送给Bob,Bob接收到对应的 和光子串 ;Bob利用 ,结合 和 ,基于BB84协议对光子串 进行测量得到 。理想情况下共享密钥 。另外,Bob利用 , , 及 产生应答序列 ;Alice和Bob利用各自拥有的序列及 分别产生序列 和 ,并对各自的 做更新。在密钥分发过程中光子的利用率为百分百,该协议既有BB84协议类似的安全性,又有单向身份认证功能。     

基于W态的量子确定性密钥分发方案

提出了一种基于W态的量子确定性密钥分发方案,方案采用在量子信道中传输更加稳定的W态作为承载信息的粒子,利用量子相干特性以及一串公开的信息序列S作为密钥分发的关键,在兼顾传输粒子稳定性的前提下能够达到54.54%的密钥分发效率,与使用GHZ态相比,在效率相差无几的情况下保证粒子在传输过程中具有更强的鲁棒性。安全分析表明,此方案能经受窃听者采取的截获——转发（重发）攻击和纠缠攻击两种攻击方式,确保通信安全可靠。同时,该方案在执行过程中不涉及任何幺正操作,简单便捷。     

预报单光子源下的经典-量子信息共信道同传系统研究

分析了密集波分复用下的经典-量子信息共信道同传系统噪声特性,提出基于预报单光子源的经典-量子信息共信道同传方案。与传统的弱相干光源相比,其可以更精确控制APD探测门限,进而实现时域滤波减少信道噪声干扰;并且可以通过控制探测器开启时间,有效避免空光子发送时的信道噪声及探测器暗计数影响。仿真结果表明,本方案提出的同传系统可有效抑制噪声干扰,与弱相干光源方案相比于更远距离达到误码率阈值,提升了安全通信距离,可作为远距离量子密钥通信共信道同传参考方案。     

一种无证书的跨域量子密钥协商协议

针对传统跨域密钥协商协议安全性不足问题,提出一种新的跨域量子密钥协商协议。在无证书密钥协商体系下,采用量子密钥协商与经典密码算法结合的方案,提高了协议适应现有通信网络架构的能力。密钥协商过程使用三粒子量子隐形传态,利用量子态不可克隆定理保障协商过程中密钥的安全性。与其他方案相比,本协议具有较高的量子比特效率,并且可以抵抗中间人攻击、重放攻击等多种内部和外部攻击手段。     

Improved nonorthogonal decoy state method in quantum key distribution with a parametric down-conversion source

With parametric down-conversion sources (PDCSs), the nonorthogonal decoy state protocol based on one vacuum and two weak decoy states is presented. The detection events on Bob’s side are divided into two groups depending on whether Alice gets a trigger or not: triggered components and nontriggered components. The triggered components are used to estimate the fractions and error rates of single-photon and two-photon pulses, and then the final secure key rate is deduced. Besides, both triggered and nontriggered components are used to deduce a more accurate value of the key generation rate. The simulation of the final key generation rate over transmission distance shows that the first method can obtain a key generation rate close to the theoretical limit of the infinite decoy state protocol, while the second method is better.     

Two-step unsymmetrical quantum key distribution protocol using GHZ triplet states

The security, efficiency, transmission distance and error rate are important parameters of a quantum key distribution scheme. In this article, the former two parameters are focused on. To reach high efficiency, an unsymmetrical quantum key distribution scheme that employs Greenberger-Horne-Zeilinger (GHZ) triplet states and dense coding mechanism is proposed, in which a GHZ triplet state can be used to share two bits of classical information. The proposed scheme can be employed in a noisy or lossy quantum channel. In addition, a general approach to security analysis against general individual attacks is presented.     

量子密钥分配协议的Petri网建模及安全性分析

量子密钥分配协议已经被证明具有无条件安全特性,但是证明过程比较复杂,不利于推广到其他量子密码协议的安全性分析和证明中.为了简化量子密码协议的安全性证明以及建立一种通用的证明方法,基于Petri网提出一种量子密钥分配协议的形式化分析方法,根据Biham的等效对称化攻击模型,将协议分为主体模型和攻击模型两部分,建立了BB84协议的Petn网模型,然后对模型进行安全性分析,分析结果表明, BB84协议是无条件安全的.该方法提高了安全性分析效率,形式上简洁统一,容易推广到其他量子密码协议的安全性分析中.     

A universal quantum key distribution method

Combining heralded pair coherent state(HPCS) with passive decoy-state idea,a new method is presented for quantum key distribution(QKD).The weak coherent source(WCS) and heralded single photon source(HSPS) are the most common photon sources for state-of-the-art QKD.However,there is a prominent crossover between the maximum secure distance and the secure key generation rate if these two sources are applied in a practical decoy-state QKD.The method in this paper does not prepare decoy states actively.Therefore,it uses the same experimental setup as the conventional protocol,and there is no need for a hardware change,so its implementation is very easy.Furthermore,the method can obtain a longer secure transmission distance,and its key generation rate is higher than that of the passive decoy-state method with WCS or HSPS in the whole secure transmission distance.Thus,the limitation of the mentioned photo sources for QKD is broken through.So the method is universal in performance and implementation.     

抗特洛伊木马攻击的量子密钥多播通信协议

提出在一个源量子节点与M个目的量子节点组成的网络中抗量子特洛伊木马攻击的组播通信协议,源量子节点构建2n+δ个EPR纠缠对,并用发送序列标记;在发送序列中随机选取n个作为检测纠缠对,利用CHSH不等式进行信道检测;发送序列中剩余n+δ个EPR纠缠对变形为非正交的量子态作为密钥,将广播明文信息分组编码成密文,利用量子态的不精确克隆复制M份发送给每个目的节点;目的节点接收密文逆向解密。分析了通信的吞吐量、信道的利用率、协议的安全性等问题。通过分析,证明该协议能有效防止特洛伊木马攻击,保证组播信息的安全。     

SARG04 decoy-state quantum key distribution based on an unstable source

A three-state protocol for the SARG04 decoy-state quantum key distribution(QKD)based on an unstable source is presented. The lower bound to the secure key generation rate is derived without using the basic hypothesis of the original decoy-state idea.The three-state SARG04 decoy-state protocol with an unstable parametric down-conversion source is considered in the simulation.The simulation results show that the protocol in this paper with an unstable source gives a key generation rate that is close to that with a stable source,and only slight advantage appears by using a stable source when the transmission distance is long.So the SARG04 decoy-state protocol with an unstable source still can obtain the unconditional security with a slightly shortened final key.     

基于单粒子态的双向认证多方量子密钥分发

量子密钥分发是一种重要的量子通信方式.为了提高量子密钥分发的可行性、安全性和效率,提出了一种基于单粒子态的具有双向认证功能的多方量子密钥分发协议.在协议中,量子网络中的任意两个用户均可在半可信第三方的帮助下进行双向认证并共享一个安全的会话密钥;协议中作为量子信息载体的粒子不需要存储,这在当前技术下更容易实现.安全性分析表明所提出协议在理论上是安全的.     

一种新的适合于Internet环境的密钥分配协议

提出了一个基于椭圆曲线数字签名密钥分配的新协议，该协议去掉了引起争议的事件标记，同时增加了可认证性，并在该协议基础上提出了适合于Internet的分级密钥分配协议。     

一种新的多用户量子密钥分发方案

提出了一种基于偏振态相位编码的多用户量子密钥分发方案。以偏振编码作为地址码以区分用户,以相位编码携带信息,具有同时调制偏振态的相位和偏振角度的特点。建立了多用户量子信道模型,通过仿真获得其安全通信距离。结果表明,本文方案不但能够有效区分多用户通信中各用户信息,而且比基于偏振编码或相位编码的量子密钥分发方案更加安全。     

A simple control system of quantum key distribution with high visibility

A relatively simple plug-and-play control system of quantum key distribution(QKD) based on PCI7300 card is demonstrated,including mechanism design,key generation and key acquisition.The system works very well at the repetition frequency of 1 MHz,and the key generation rate is 100 k/s.A visibility of better than 95% over 50 km-long fiber at 1.31 μm is obtained,which is stable under ordinary lab conditions for 24 h without any feedback control or adjustment.The presented system is a quite promising candidate to realize the QKD in the future.     

融合量子密钥分配的电信运营商密码应用体系

基于量子密钥分配(quantum key distribution,QKD)的通信网络具备实现“perfect secrecy”(完美保密性)的能力,当前还不能满足大规模应用的需求,在实际应用中需要结合经典密码技术。提出了融合量子密钥分配的电信运营商密码应用体系的功能架构模型,介绍了模型的层次结构、核心的网元和功能模块以及接口关系,给出了应用体系的整体框架,介绍了框架的主要组成部分,描述了应用体系的典型应用场景及其工作流程。