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1.
张维  韩正甫 《物理学报》2019,68(7):70301-070301
最近有研究者提出了一个基于三粒子最大纠缠态GHZ态的量子广播多重盲签名协议,它能满足一个重要消息需要多人签发,但出于隐私保护要求每一个签名者都不能获取消息的具体内容这一应用需求,并有望应用于电子银行系统.本文给出了一个基于三粒子部分纠缠态的量子广播多重盲签名协议,与原协议相比,该协议用三粒子部分纠缠态代替三粒子极大纠缠GHZ态,并且能不降低协议的安全性.新协议不再依赖于极大纠缠态,仅仅需要在通信参与者之间分享部分纠缠态就可以完成该签名方案,这在一定程度上节约了纠缠资源,降低了协议的实现条件,提高了协议的可应用性.这也充分体现了多体部分纠缠态也可以作为一种量子资源来实现既定的量子通信任务.  相似文献   

2.
远程认证协议能有效的保证远程用户和服务器在公共网络上的通信安全。提出一种匿名的安全身份认证方案,通过登录 的动态变化,提供用户登录的匿名性,通过用户和服务器相互验证建立共享的会话密钥,抵抗重放攻击和中间人攻击,实现用户安全和隐私,通过BAN逻辑分析证明改进方案的有效性,通过安全性证明和性能分析说明了新协议比同类型的方案具有更高的安全性、高效性。  相似文献   

3.
为实现电梯远程呼叫的应用目标,对即时通讯机制进行了分析,将即时通讯工具引入电气控制领域,提出了基于即时通讯的电梯远程呼叫系统;设计并实现了即时通讯服务器/数据库、电梯终端与用户终端三层架构的通讯系统,给出了三方之间网络通讯实现时的信息交互架构;经过测试,该系统满足一般工程应用的需求,提升了电梯系统的整体运行质量与效率;在即时通讯技术的应用与电梯物联网技术的发展上有一定的参考价值和推广价值。  相似文献   

4.
复合量子密钥分发系统双速协议及其安全性分析   总被引:1,自引:0,他引:1       下载免费PDF全文
杨理  吴令安  刘颂豪 《物理学报》2002,51(11):2446-2451
基于真空光速c是极限信号速度这一基本假设,提出了复合量子密钥分发(QKD)系统和双速协议,并证明双速协议的安全性与原BB84协议的安全性相同.结果表明,双速协议在将量子密钥生成效率从50%提高到100%的同时,还降低了窃听者Eve可能得到的信息量.双速协议由于打破了公开讨论之前Bob和Eve的对等地位,使QKD在概念上有了明显的改进,使协议基的选择空间有了本质性的扩充.具体给出了三个双速协议的实例,并详细分析了它们在截取重发攻击下的安全性 关键词: 量子密码 光纤量子密钥分发 双速协议  相似文献   

5.
目前,量子行走已广泛应用于量子计算和量子模拟中,并可应用于量子隐形传态中。提出了一种基于量子行走的电子支付协议。在协议中,买家基于可信第三方平台,将部分购物信息通过量子行走传送给银行和商家,完成一次网络购物。此协议将量子行走与电子支付相结合,使参与方仅需制备单光子便可以得到所需的纠缠资源,便于量子态的制备和实现。同时,协议不仅满足购物清单对银行保密,还实现了购买者的部分私人信息对商家保密,提高了隐私保护能力。最后的安全性分析表明,该协议可以抵御内部和外部攻击,对于当前技术是安全可行的。  相似文献   

6.
基于双模压缩态的量子投票协议   总被引:1,自引:0,他引:1       下载免费PDF全文
易智  何广强  曾贵华 《物理学报》2009,58(5):3166-3172
提出了一种基于双模压缩态的基本量子投票协议,该协议通过随机选择信号加载的方式,充分利用量子信号测不确定性原理实现了分布式投票系统.并在此基础上分析可能遇到的攻击.双模压缩态的模间关联性保证了该方案的安全性. 关键词: 量子投票协议 双模压缩态 不确定性原理  相似文献   

7.
唐琳  方方  罗正华 《应用声学》2016,24(2):195-197
针对目前同步串行协议通信速率低和可靠性差的现状,设计了一个基于ARM加交换芯片的协议转换器来完成同步串行协议到网络通信协议的转换。设计采用S3C2440为核心处理器,并通过服务器和客户端建立连接,以套接字的形式将SPI协议转换成TCP协议接入到以太网,采用网络调试助手和串口调试助手对客户端和服务器的协议转换通信进行测试和分析。实验结果表明服务器通过SPI总线发出的数据经过封包后构造成可以在网络上转发的报文,经过交换芯片的端口转发到达客户端完成SPI到TCP协议的转换。  相似文献   

8.
DSP处理器一般不带网络接口,设计了基于TMS320F2812连接高性能网络控制器AX88796组成的带网络接口的开发系统.该系统采用了AX88796的底层驱动程序,裁减TCP/IP协议栈并将其移植到DSP开发系统上.重点解决了驱动初始化,网卡的接收缓冲环管理和TCP/IP协议校验和计算等问题,实现了F2812驱动AX88796,通过TCP/IP协议接入互联网.  相似文献   

9.
目的:无线传感器网络发展迅速,但传感器的高能耗问题成为制约其发展的主要瓶颈,高效节能的路由协议设计成为研究热点。方法:针对目前无线传感器网络常用的LEACH路由协议存在的簇首能耗过分集中、簇首分布不均衡问题,提出了改进的路由协议EEACRA,在总结、分析LEACH路由协议现有问题的基础上,给出了EEACRA路由协议的簇首选取门限值、簇首位置调整算法和基于能量代价最小的簇间多跳路由算法的实现方法,同时给出了具体的实现EEACRA协议的工作流程和关键算法。在MATLAB环境下对LEACH路由协议和EEACRA路由协议进行了仿真,对比了不同能耗降低措施对网络能耗降低的贡献。结果:仿真结果表明EEACRA路由协议的网络稳定期较LEACH路由协议有较大的改善。结论:证明了改进的路由协议EEACRA可以有效地提高网络的稳定期。  相似文献   

10.
随着能源危机、气候变暖、环境污染等问题日益严重,发展分布式清洁能源已经成为一项国策。大量企业采用基于RS485、RS232等通信接口的Modbus协议作为一种通用工业标准在光伏逆变器等电站设备中作为数字化通信标准,针对不同厂家、不同型号的光伏逆变器与光伏主站之间存在多种协议规约需要主动适配的工程问题,通过对不同厂家、不同型号的光伏逆变器所涉及各种类型通信协议的深入分析和大量工程应用实践,提出了一种用于自动解析光伏逆变器通信协议的算法模型,并基于此模型研发了一种基于光伏逆变器通信协议的智能匹配技术,有效解决了不同类型光伏逆变器与光伏主站的通信问题。经过工程应用验证表明,应用该技术可以实现已解析协议的快速接入、新接入协议的快速解析匹配和已接入设备的现场调试等功能。  相似文献   

11.
Cyclic competition game models, particularly the “rock–paper–scissors” model, play important roles in exploring the problem of multi-species coexistence in spatially ecological systems. We propose an extended “rock–paper–scissors” game to model cyclic interactions among five species, and find that two of the five can coexistent when biodiversity disappears, which is different from the “rock–paper–scissors” game. As the number of fingers is five, we named the new model the “fingers” game, where the thumb, forefinger, middle finger, ring finger, and little finger cyclically dominate their subsequent species and are dominated by their former species. We investigate the “fingers” model in two ways: direct simulations and nonlinear partial differential equations. An important finding is that the number of species in a cyclic competition game has an influence on the emergence of biodiversity. To be specific, the “rock–paper–scissors” model is in favor of maintaining biodiversity in comparison with the “fingers” model when the variables (population size, reproduction rate, selection rate, and migration rate) are the same. It is also shown that the mobility and reproduction rate can promote or jeopardize biodiversity.  相似文献   

12.
Downstep in pitch contour of Chinese Putonghua is examined using subtly designed sentences by controlling tone combinations. The results show both automatic and nonautomatic downstep phenomena exist in Chinese. In non-automatic downstep, low tones compress downwards the pitch range of the following syllables. and the main influence of downstep is on topline. Low tone not only lower the topline behind it, but also raise the high tones before it, the effects are compatible with each other. In automatic downstep, the topline of pitch contour in intonational phrase is presented as a linear downtrend, but it differs among speakers due to the effect of personal stress practice. In comparison with downstep phenomenon in other tone or non-tone languages, the downstep ratio in Chinese is not constant, and the domain of downstep is not limited within the adjacent tones.  相似文献   

13.
The differences of the pitch and duration of Chinese syllables between Putonghua (PTH) and Taiwan Mandarin (TM) were studied. The speech materials to be used are not only isolated syllables, but also sentences. The results reveal that: For the isolated syllables, T1 and T2 in TM are influenced by Minnan dialect, therefore their pitch are lower than those in PTH. T3 is fall-rise in PTH, while it is fall in TM. Moreover, the syllable duration sequence for different tone is T3〉T2〉T1〉T4 in PTH, while it is T1〉T2〉T3〉T4 in TM. For the syllables in sentences, T2 is mid-rise in PTH, while it is mid-level in TM. And the T3 is longer than T4 but shorter than T1 or T2 in PTH, while it is the shortest in TM. Furthermore the effects of prosodic phrase boundary on duration for different tones are almost the same in PTH, but the lengthening part of T1 or T2 is longer than that of T3 or T4 in TM.  相似文献   

14.
It is shown that SU(2) QCD admits an dual Abelian-Higgs phase, with a Higgs vacuum of a type-Ⅱ superconductor. This is done by using a connection decomposition for the gluon field and the random-direction approximation. Using a bag picture with soft wall, we presented a calculational procedure for the glueball energy based on the recent proof for wall-vortices [Nucl. Phys. B 741(2006)1].  相似文献   

15.
16.
Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.  相似文献   

17.
Based on the research in Ref. [5][Materials Science and Engineering, 1989; A122: 57 63], an improved model of heat source is set up, the different modes of Lamb wave in an isotropic sample generated by a chopped electron beam at frequency f are obtained with integral transform and normal function expansion method, and the output signal of PZT coupled at the back surface of the sample is found out. The generation mechanism of SEAM (Scanning Electron Acoustic Microscopy) signal is discussed. It shows that the SEAM is a near field imaging technique with high spatial resolution and its best lateral spatial resolution is about 2√2α (α is the radius of the focused electron beam). Some of experimental results of SEAM images are presented in the paper and it shows that the spatial resolution of SEAM is better than 0.5 μm and smaller than the thermal diffusion length of the sample. Therefore the character of near field imaging in SEAM is also proved experimentally.  相似文献   

18.
Transmission spectra of coupled cavity structures (CCSs) in two-dimensional (2D) photonic crystals (PCs) are investigated using a coupled mode theory, and an optical filter based on CCS is proposed. The performance of the filter is investigated using finite-difference time-domain (FDTD) method, and the results show that within a very short coupling distance of about 3λ, where λ is the wavelength of signal in vacuum, the incident signals with different frequencies are separated into different channels with a contrast ratio of 20 dB. The advantages of this kind of filter are small size and easily tunable operation frequencies.  相似文献   

19.
The key to the restoration of rotational motion blurred image is how to restore the image under a low cost and to correct the irreversibility of the degradation function matrix.Based on the special qualities of degradation function matrix and precise deduction in space-domain, we present a new approach using gradient-loading for restoration of rotational blurred image.By easily adding a gradient operator, the irreversibility of the original matrix is corrected and can be applied for inverse filtering then.Gradientloading is the optimized approach which combines the advantages of both the approaches using constrained least square filtering and traditional diagonal-loading.Compared with the approach using least square filtering, its peak signal-to-noise ratio (PSNR) is improved from 3.18 to 6.46dB, while the computing time is reduced to 1/2-1/3.Experimental results demonstrate the effectiveness, noise-resistibility, robustness, and low complexity of this approach, which make it more suitable for real-time environment.  相似文献   

20.
We propose an all-optical logic device made of a bent tapered Y-junction waveguide with a Kerr-type nonlinear interface. It could provide an AND gate, OR gate, and exclusive-OR (XOR) gate. We could obtain different transmission results by adjusting the bending angle. The numerical simulation results show that the device functions as AND, OR, and XOR gates.  相似文献   

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