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101.
102.
提出了一个多用户量子信令树型传输系统,并详细阐述了信令的传输过程.研究了系统中信令受到特洛伊木马攻击的损伤模型及其修复的必要性.将量子密钥分发的思想引入量子信令安全的直接通信中,分析了采用非正交量子态,以克服特洛伊木马攻击的问题,从而提高了信令传输的安全性.对多用户量子信令树型传输系统进行改进,提出了新的广义的多用户量子信令树型拓扑传输模型.研究结果表明,本文所提出的对多用户信令攻击的修复策略可有效地防止特洛伊木马攻击,从而保证信令传输过程安全有效的进行. 相似文献
103.
Dr. Gavin S. Heverly‐Coulson Prof. Russell J. Boyd Prof. Otilia Mó Prof. Manuel Yáñez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(11):3629-3638
The reactivity of disulfide and diselenide derivatives towards F? and CN? nucleophiles has been investigated by means of B3PW91/6‐311+G(2df,p) calculations. This theoretical survey shows that these processes, in contrast with the generally accepted view of disulfide and diselenide linkages, do not always lead to S? S or Se? Se bond cleavage. In fact, S? S or Se? Se bond fission is the most favorable process only when the substituents attached to the S or the Se atoms are not very electronegative. Highly electronegative substituents (X) strongly favor S? X bond fission. This significant difference in the observed reactivity patterns is directly related to the change in the nature of the LUMO orbital of the disulfide or diselenide derivative as the electronegativity of the substituents increases. For weakly electronegative substituents, the LUMO is a σ‐type S? S (or Se? Se) antibonding orbital, but as the electronegativity of the substituents increases the π‐type S? X antibonding orbital stabilizes and becomes the LUMO. The observed reactivity also changes with the nature of the nucleophile and with the S or Se atom that undergoes the nucleophilic attack in asymmetric disulfides and diselenides. The activation strain model provides interesting insights into these processes. There are significant similarities between the reactivity of disulfides and diselenides, although some dissimilarities are also observed, usually related to the different interaction energies between the fragments produced in the fragmentation process. 相似文献
104.
In order to increase the accuracy of turbulence field reconstruction, this paper combines experimental observation and numerical simulation to develop and establish a data assimilation framework, and apply it to the study of S809 low-speed and high-angle airfoil flow. The method is based on the ensemble transform Kalman filter(ETKF) algorithm, which improves the disturbance strategy of the ensemble members and enhances the richness of the initial members by screening high flow field sensitivity ... 相似文献
105.
逆同余发生器的密码分析 总被引:1,自引:0,他引:1
使用格中的最短向量对未知向量进行逼近的方法,证明了在已知乘子a和模数p的条件下,若连续的wi满足|ui-wi|是一个很小的数时,在多项式时间内可以恢复出逆同余发生器的移位B. 本文的结论表明将逆同余发生器直接应用于密码学必须十分慎重. 相似文献
106.
Wang Xiang-bin Ying Hao Ma Huai-xing Peng Cheng-zhi Yang Tao Pan Jian-wei 《Frontiers of Physics in China》2006,1(3):251-255
In principle, quantum key distribution (QKD) can be used to make unconditionally secure private communication. However, the
security of the existing real system for QKD needs to be carefully examined. Actually, the existing experiments based on weak
coherent states are not secure under photon-number-splitting attack. Fortunately, the decoy-state method and the entanglement-distribution
method can be used to realize the unconditionally secure QKD based on real-life systems with existing technology. 相似文献
107.
108.
109.
Novel cis-chelated bidentate bis(NHC)-Pd(II) complexes derived from 1,1′-binaphthyl-2,2′-diamine (BINAM) bearing weakly coordinating acetate or trifluoroacetate counterions have been synthesized and their structures have been characterized by X-ray diffraction of single crystals. We found that these bis(NHC)-Pd(II) complexes were highly effective in the allylation of aldehydes with allyltributyltin to give the corresponding products in good to excellent yields in most cases at room temperature. 相似文献
110.
通过研究密码芯片运行时的光辐射迹及其数据依赖性, 建立了操作数汉明重量与泄漏光子数的对应关系, 提出了一种简单有效的针对高级加密标准(AES)加密算法的密码芯片光辐射分析方法. 根据密码芯片运行时的光泄漏特性, 利用时间相关单光子计数技术搭建了光辐射分析攻击实验平台, 在AES加密算法执行第一次的轮密钥加操作后和字节替换操作后分别进行光泄露信号采集, 对基于操作数Hamming weight和AES密码芯片泄漏光子数对应关系的密钥分析攻击方法的有效性进行了实验验证, 通过选择几组明文成功地破解了AES加密算法的密钥. 实验结果表明, 当密码芯片的泄露光子数与操作数的汉明重量呈近似线性关系时, 该种光辐射密钥分析攻击方法对AES密码芯片的安全性构成了严重的威胁. 相似文献