Implementing Operating System Support for Extended Trusted Path in TPM-Capable Environments

Trusted path is one of the crucial features that operating systems must provide for fundamental security support. In order to explore the possibility of implementing a trusted path mechanism with the support of trusted platform module （TPM） technologies, and to support TPM capabilities in operating systems, the paper extended the scope of the conventional trusted path to cover the situation in which a user communicates with software residing on a remote host. The paper combined the concept of operating system support for trusted path with that for TPM platforms, and proposed the architecture of an extended trusted path mechanism in operating system with considerations on TPM-capable platforms support. As part of the author＇s research in secure operating systems, the work of the paper was carried out with Linux as an experimental prototype system. The research result shows that TPM capabilities can strengthen extended trusted path mechanisms of operating systems.     

动态电压恢复器的控制策略

通过把负载电压看作动态电压恢复器(DVR)的控制对象,开关器件的占空比看作控制量,电网电压和负载电流看作干扰量,可将DVR的数学模型简化为单输入单输出系统.结合控制量的计算方法,推导出了控制量到被控对象和干扰量到被控对象的传递函数.分析传递函数可知,负载电流特别是其中的高频分量会使DVR的补偿性能变坏.提出了误差校正控制方法,在传统电网电压前馈的基础上通过误差校正实现了负载电流前馈,基本消除了负载电流的影响.仿真结果验证了理论分析的正确性.     

生物组织冻结相变过程的数值模拟

建立了生物组织(含正常生物组织和肿瘤)冻结过程的传热模型.生物组织作为一种多孔介质,其相变发生在一个温度范围内,且存在一个固相与液相共存的糊状过渡区.采用显热容法模拟了生物组织冻结过程中的传热和冰晶增长过程.模拟结果显示,在冻结过程中,冷刀的初始温度越低,冷刀的降温速率越快,生物组织内温度下降和冰晶增长的速率越快.结果还表明组织中液相流动会增加生物组织内传热和冰晶生长的速度.计算结果为冷刀设计和冷冻外科手术提供了理论依据.     

我国民营企业信用文化体系建设的对策研究

改革开放以来,我国民营企业迅猛发展,但在信用文化建设方面严重缺失,由此导致了经济秩序失范现象。本文阐述了民营企业失信对发展社会主义市场经济的危害,探讨了建立民营企业信用文化体系的新思路。     

磁控技术成膜的工艺研究与微观表征分析

在氩气的气氛中采用直流磁控溅射方法,在玻璃基片上制备铂薄膜热敏电阻,并对铂薄膜的微观组织进行分析,同时研究了磁控溅射镀膜工艺参数对制备铂薄膜的影响,分析了参数中溅射功率、溅射时间与膜厚的关系。并利用Matlab软件建立了溅射时间、溅射功率与膜厚的三维关系模型图。     

基于活动预调度的工作流管理研究

在工作流管理中,通过将顺序执行的活动重叠执行来缩短过程执行周期、提高系统的执行效率,是长久以来大家关注的问题。传统支持过程管理的系统在这方面没有提供足够的支持手段。本文通过对实际应用情况的分析抽象,提出了用活动预调度的方法来解决以上问题,并针对项目管理型系统提出了解决方案:基于信息约束驱动执行的工作流管理机制。分析证明,预调度在实际工作流管理中是有意义且可行的。     

废旧电池回收处理利用方法综述

针对废电池对环境存在的潜在危害,简要介绍了不同类型的废电池回收综合利用技术。     

Security Architecture of Trusted Virtual Machine Monitor for Trusted Computing

With analysis of limitations Trusted Computing Group （TCG） has encountered, we argued that virtual machine monitor （VMM） is the appropriate architecture for implementing TCG specification. Putting together the VMM architecture, TCG hardware and application-oriented ＂thin＂ virtual machine （VM）, Trusted VMM-based security architecture is present in this paper with the character of reduced and distributed trusted computing base （TCB）. It provides isolation and integrity guarantees based on which general security requirements can be satisfied.     

Provable Efficient Certificateless Group Key Exchange Protocol

Certificateless public key cryptography （CL-PKC） avoids the inherent escrow of identity-based cryptography and does not require certificates to guarantee the authenticity of public keys. Based on CL-PKC, we present an efficient constant-round group key exchange protocol, which is provably secure under the intractability of computation Diffie-Hellman problem. Our protocol is a contributory key exchange with perfect forward secrecy and has only two communication rounds. So it is more efficient than other protocols. Moreover, our protocol provides a method to design efficient constant-round group key exchange protocols and most secret sharing schemes could be adopted to construct our protocol.     

Escrow-Free Certificate-Based Authenticated Key Agreement Protocol from Pairings

Key agreement protocols are essential for secure communications. In this paper, to solve the inherent key escrow problem of identity-based cryptography, an escrow-free certificate-based authenticated key agreement （CB-AK） protocol with perfect forward secrecy is proposed. Our protocol makes use of pairings on elliptic curves. The protocol is described and its properties are discussed though comparison with Smart＇s protocol.