击键特征加强口令身份认证安全性的研究

目前,绝大多数计算机系统的安全性都是通过口令保护机制实现的,但口令易被盗用,存在着安全隐患.为此本文提出了将传统的口令认证机制同用户输入口令时生成的击键特征相结合进行身份认证,以此来加强传统的口令认证方式的安全性.同时建立了BP神经网络对此进行实验,并给出了实验结果.     

击键特征加强口令身份认证安全性的研究

目前 ,绝大多数计算机系统的安全性都是通过口令保护机制实现的 ,但口令易被盗用 ,存在着安全隐患。为此本文提出了将传统的口令认证机制同用户输入口令时生成的击键特征相结合进行身份认证 ,以此来加强传统的口令认证方式的安全性。同时建立了 BP神经网络对此进行实验 ,并给出了实验结果。     

OMECNN:一种基于有序马尔可夫枚举器和判别神经网络的口令生成模型

基于口令的身份鉴别是目前最流行的鉴别方式之一,利用口令生成技术进行大规模口令集的生成,进而检测现有用户口令保护机制的缺陷、评估口令猜测算法效率等,是研究口令安全性的重要手段.本文提出一种基于有序马尔可夫枚举器和判别神经网络的口令生成模型OMECNN,使用有序马尔可夫口令枚举器按照口令组合概率的高低生成组合口令,同时基于判别神经网络进行打分筛选口令,选出得分高于阈值的口令组成最终口令集.采用本文提出方法生成的口令集具有按照口令组合概率高低排序的特点,以及符合真实训练口令集的口令分布的特点.实验结果表明,在生成10~7条口令时,OMECNN模型生成的口令集在Rockyou测试集上的匹配条目比OMEN模型高出16.60%,比PassGAN模型高出220.02%.     

基于PCA算法的人脸识别研究及其GUI实现

随着科学技术的飞速发展,传统的身份识别(如门禁卡,身份卡,口令等)安全系数比较低,容易被破解,而生物特征识别技术使得身份鉴别更加可靠,能够达到期望的安全系数;针对上述问题,介绍了一种人脸识别常用的算法及其算法的改进,并采用ORL数据库作为实验库进行了算法改进前后的识别率比较实验,最后在Matlab中通过图形化界面进行了验证实现。     

用VB实现一次性口令的用户认证机制

身份认证和鉴别目前可以通过多种手段实现,口令是其中的一种形式,讨论了用VB实现一次性口令的方法及解决一次性口令的算法不易记忆的问题。     

基于鼠标动力学模型的用户身份认证与监控

针对计算机系统安全中的用户身份识别和监控等基本问题,提出了一种利用鼠标动力学行为特征进行身份识别的新方法.通过采集各种应用环境下的鼠标行为数据,从交互和生理2个层面上对人机交互过程中计算机用户的鼠标行为特征进行建模、分析,以达到实时监测用户身份、检测非法用户的目的.所提方法可为身份监控原型系统实时采集用户的行为数据,并将当前的行为与用户的历史行为模型进行比较,以判断和检测用户身份,再依据判断检测结果产生实时的响应,从而有效防止非法用户侵入.实验采集井分析了10个用户的鼠标行为数据,通过特征降维与神经网络分类相结合的算法,得到了0.48%的误识率和2.86%的拒识率,充分展示了基于鼠标动力学行为模型进行身份认证和监控的可行性.     

基于CNN和RNN的自由文本击键模式持续身份认证

个人击键节奏模式具有很难被模仿的特点并可以用于身份认证。根据个人自由文本输入时的击键数据可以学习到个人独有的击键模式。基于对用户自由文本击键输入的检测,能够在不影响用户输入的情况下完成对用户身份的持续认证。该文提出将整体击键数据划分成固定长度的击键序列,并且根据击键的时间特征将击键序列中的击键时间数据转化成击键向量。使用卷积神经网络(convolutional neural networks,CNN)加循环神经网络(recurrent neural networks,RNN)的模型进行个人击键向量序列进行学习,用于身份认证。结果表明:模型使用公开数据集进行实验获得最优拒真率(false rejection rate,FRR)为1.95%,容假率(false acceptance rate,FAR)为4.12%,相等错误率(equal error rate,EER)为3.04%。     

基于单向散列函数的智能卡鉴别方案

提出了一种在智能卡中实现的基于单向散列函数的远程身份鉴别方案，用户能自己选择口令并且系统不需要维护任何与用户口令相关的信息，系统中用户不受限制，用户利用智能卡以及口令便可成功地登录到远程系统，攻击者不能从公开或传送的信息中获得用户秘密信息，也不能冒充别的合法用户，此外，本方案还能抵抗登录请求的重播。     

云环境下基于PKI的一次性口令身份认证系统设计

当前身份认证系统口令设计过程复杂,不仅容易出现认证错误的现象,而且大大增加了计算复杂度,影响整体性能。为此,提出一种新的云环境下基于PKI的一次性口令身份认证系统,给出设计系统总体结构,其主要由CA证书服务模块、RA注册模块、认证模块与用户模块构成。身份认证选用用户数字证书与一次性口令相结合的形式,对用户名与一次性口令进行验证时,通过用户名得到其数字证书,利用“挑战-应答”协议判断用户是否合法。介绍了一次性口令生成技术,给出公开大素数与保密大素数的确定过程。实验结果表明,采用所设计系统对云环境下用户进行身份认证,不仅认证精度高,而且整体性能强。     

网络在线安全预警中一次性口令身份认证方法的实现

当前网络在线安全预警中身份认证方法大多通过静态口令实现,不仅易于猜测,而且容易被窃听,安全性较差。为此,提出一种新的网络在线安全预警中一次性口令身份认证方法,给出一次性口令身份认证原则,在进行用户注册的过程中,令用户输入注册的用户ID、用户口令PW及两个随机数,对上述数据进行计算,获取首次认证数据,经安全信道传输至服务器中储存,以供第一次认证使用。给出用户登录服务器时一次性口令身份认证的详细过程。实验结果表明,所提方法在用户数量较多和内部用户、外部用户均冒充合法用户的情况下,均可保持较高的认证精度,且认证效率高。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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