基于USBkey的虚拟实验平台动态身份认证方案设计及实现

本文提出了一种基于USBkey的动态身份认证方案,该方案利用公钥密码算法和USBKey的硬件保护特性,使密钥能够安全方便的分发和保存,避免了使用时间戳带来的重放攻击的潜在风险,并能抵抗假冒攻击和口令攻击.该动态身份认证方案很好地满足了虚拟实验平台身份认证系统的实际需求.     

可信DRM中直接匿名认证的应用研究

数字版权管理(DRM)技术一直致力于数字内容的保护,特别是防止售后非法使用.而所依靠的密码学保护措施很容易被攻击和破解.为了在硬件方面加入保护,可信DRM引入了TPM安全芯片,借助TPM在身份认证、许可授权等方面加强保护.为了解决身份认证时用户隐私泄露的问题,可信DRM采用了直接匿名认证协议.在此基础上提出了基于零知识认证和ElGamal算法的双随机数签名的改进方案,并介绍了该方案在可信DRM中是如何应用的.最后经过分析得出该方案在安全性和匿名性方面都有所提高.     

一种认证方案的形式分析

首先对用于认证方案分析的BAN逻辑进行了分析并指出了它的限制,在此基础上提出了一种新的扩展,并将BAN逻辑应用到基于HMAC认证方案的分析中。通过对已实现的远程访问认证方案的分析,证明了上述扩展的有效性和合理性,分析结果表明认证方案达到了预期的安全设计目标。     

可信网络连接双向认证协议的设计与分析

针对可信网络连接认证协议的现有方案存在单向认证、平台身份和配置信息泄露、无法抵御伪装及重放攻击等安全问题,提出了一种新的认证协议。该协议通过引入可信第三方实现了双向用户身份和平台身份的认证,防止了伪装攻击。直接匿名证明方法和时间戳的应用,保护了平台身份和配置信息的安全,防止了重放攻击。采用BAN逻辑对协议进行形式化描述及分析,验证了本协议可以提高认证的安全性,具有较高的应用价值。     

远程无纸化阅卷系统身份认证机制的构建方案

首先介绍基于PKI(即“公共密钥体系”)的身份认证机制 ,然后提出远程无纸化阅卷系统中基于PKI的身份认证机制的设计和开发过程 ,接着讨论这一方案在实际应用中的使用方法 .最后 ,对该方案安全性作简要分析 .     

基于OTP的移动商务身份认证机制设计与研究

移动商务的身份认证问题已成为制约移动商务发展的瓶颈.一次性口令(OTP)技术实现简单、成本低、无须第三方认证的特点使其较适合移动商务的身份认证.利用椭圆曲线密码体制实现数字签名,提出一套基于OTP的移动商务身份认证机制,最后利用BAN逻辑方法证明了该机制的安全性.     

一种基于AAA证书和身份签名的混合认证方法

基于移动IPv6结合证书认证和身份签名认证,对移动节点安全提出一种快速、低成本和扩展性好的混合认证方法.该方法综合证书认证和身份签名认证的优点,在认证过程中不完全依赖于可信第三方的安全认证,能够实现移动节点与接入网络的双向认证.并用BAN逻辑方法对提出的改进方法进行了分析,结果表明该方法提高了移动节点的认证效率.     

对NPKI机制的形式化分析

通过一对等实体通信的实例说明了NPKI的认证原理，在分析了传统PKI公钥证书认证原理的基础上，较为具体地说明了NPKI的身份认证过程，指出了NPKI是一种高效率的证书认证机制。然后对NPKI按照BAN逻辑进行了形式化，在明确其初始条件后，按照BAN逻辑中的有关推理规则，重点证明了NPKI是一种安全可靠的身份认证机制。     

移动Adhoc网络环境下的一种安全的通信方案

移动Adhoc网是一种开放式、无中心、自组织的无线局域网,它的开放通信信道导致它在认证、路由、通信时的安全性很难得到保证。在本文,一种安全的移动Adhoc通信方案被提出,该方案首先对认证中心实行分布式管理,由多个节点协同颁发CA证书,路由建立时,利用CA证书和公钥加密技术对通信双方的信息的可靠性进行验证,在会话密钥协商时,采用Diffic-Hellman算法实现了密钥的协商与交换。最后使用BAN逻辑对该方案进行安全性分析,分析结果证明该方案具有较高的安全性和有效性。     

一种基于软令牌的企业即时通信双向认证方案

为了提高EIM(Enterprise Instant Messenger)的安全性,在对比当前常用认证技术的基础上,提出了一种结合HASH函数、对称密码机制以及挑战/应答机制的基于软令牌的双向认证方案.最后对该方案进行了性能分析.结果表明:该方案具有保护用户身份信息,防止诸如重放、假冒和穷举等常见身份认证攻击,实现双向...     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.