基于信任扩展的可信虚拟执行环境构建方法研究

为保护虚拟机运行环境及上层服务软件的完整性、安全性,提出了一种基于信任扩展的可信虚拟执行环境的构建方法.首先,建立物理平台配置寄存器(PCR,platform configuration register)与虚拟PCR的映射关系,以此实现虚拟可信平台模块(vTPM)与底层可信计算基的绑定;其次,利用本地vTPM管理器签...     

Label-based protection scheme of vTPM secret

The virtual trusted platform module (vTPM) played an important role in virtualization of trusted computing.According to security problems of existed vTPM,a protection scheme based on vTPM label was proposed.Firstly,a vTPM label was created for each virtual machine.This label had four main components,signature information,encryption information,measurement information and status information.Then,the security-enhanced vTPM dynamic migration protocol based on vTPM label status information was designed,to ensure the security of vTPM during live migration based on status information of vTPM label.Experiments show that the proposed scheme can protect vTPM secrets effectively and the increased performance cost during live migration is only 19.36%.     

基于虚拟机的可信计算

当前,虚拟机技术和可信计算技术是两大热门技术,可信计算技术是实现信息系统安全的重要手段。是否可以在虚拟机的环境下,通过结合虚拟机和可信计算的技术优势,来实现终端系统与网络的可信,提高整个信息系统的安全？研究了如何设计一个基于虚拟机的可信计算平台安全架构,并进一步研究了虚拟化TPM的问题。同时,分析并总结了TCG定义的可信链技术。在此基础上,提出了虚拟机环境下可信链的实现方法,加强终端系统与网络的安全性。     

基于扩展LS的可信虚拟平台信任链分析

针对可信虚拟平台信任链的形式化分析问题,建立了包括虚拟机和虚拟信任根在内的可信虚拟平台完整的信任链模型,并详细定义其应满足的信任属性,通过扩展LS2,验证了可信虚拟平台信任链模型能够有条件地满足其正确性、唯一性。对实例系统分析表明本文所建立信任链模型的通用性及基于扩展LS2分析方法的有效性。     

可信终端动态运行环境的可信证据收集机制

可信计算的链式度量机制不容易扩展到终端所有应用程序,因而可信终端要始终保证其动态运行环境的可信仍然困难.为了提供可信终端动态运行环境客观、真实、全面的可信证据,提出了可信终端动态运行环境的可信证据收集机制.首先,在可信终端的应用层引入一个可信证据收集代理,并将该代理作为可信平台模块(trusted platform module,简称TPM)链式度量机制的重要一环,利用TPM提供的度量功能保证该代理可信;然后通过该代理收集可信终端的内存、CPU、网络端口、磁盘文件、策略配置数据和进程等的运行时状态信息,并利用TPM提供的可信存储功能,保存这些状态信息作为终端运行环境的可信证据,并保障可信证据本身的可信性.该可信证据收集机制具有良好的可扩展性,为支持面向不同应用的信任评估模型提供基础.在Windows平台中实现了一个可信证据收集代理的原型,并以一个开放的局域网为实验环境来分析可信证据收集代理所获取的终端动态运行环境可信证据以及可信证据收集代理在该应用实例中的性能开销.该应用实例验证了该方案的可行性.     

Efficient ID-based TPM key loading scheme for trusted platform

One important function in trusted computing is protected storage,which can protect unlimited amount of data and keys.In the existing trusted platform module(TPM)key loading scheme for trusted platform,a computing platform with TPM as its trusted anchor,the total times of loading operation is the same as the number of the loaded target object's ancestors,resulting in low efficiency of loading a TPM key which has many ancestors.To improve efficiency,an identity-based TPM key loading scheme is proposed.In this scheme,the times of loading operation is only two when any TPM key is loaded into TPM.Therefore,the required time cost for loading a TPM key can be reduced,especially for complex TPM key storage hierarchy.By analyzing the correctness,security,efficiency and feasibility,the proposed scheme has the better theoretical and application value.     

基于TPM的可信集群系统设计与实现

集群系统既有分布式系统的特点,又有单一系统的特征。由于传统集群计算节点缺少可信计算平台的支持,集群作为一个单一的系统缺少可信安全技术的支持。作为一个分布式系统,其可信安全机制和信任链传递机制又很不同于单机系统。在TCG可信计算的规范和可信链的基础之上,提出了可信集群的构架,构建了基于TPM的可信集群,实现了基于可信集群架构的可信集群系统。针对集群中的应用,对所实现的可信集群系统如何解决集群中的可信安全问题作了探讨和研究。     

Survey on trusted cloud platform technology

Information security technology confronts severe challenges because of the safety demands of cloud computing.The trustworthiness and self-safety of cloud computing platform are the foundation of cloud computing security.The confidence of cloud users is the key issue the deep development and popularization for cloud computing.The trusted cloud computing technology provides a feasible solution.From the standpoint of guaranteeing the trustworthiness of cloud computing platform,related research progresses on trusted virtualization,construction of trusted cloud platform and trusted virtual machine were introduced.Additionally,the characteristics,application scopes and effectiveness of typical schemes were analyzed and compared.Finally,current limitations and possible directions for future research were discussed.     

嵌入式系统的可信计算

文章介绍了可信计算的基本概念,给出嵌入式系统可信计算的硬件设计要求,具体阐述其中CPU和可信平台模块设计思路。     

跨平台的可信执行环境模块方案研究

针对现有TPM、MTM等可信计算模块不能跨平台使用,未考虑算法、协议、功能更新等问题,提出一种基于硬件的可信执行环境模块（TEEM, trusted execution environment module）架构,该架构利用ARM TrustZone技术构建一个运行在硬件安全隔离环境中的可信计算模块。该模块能够为多种平台提供可信计算功能,具备较强的移动性和便携性,并且允许用户根据需要灵活地配置、升级模块的功能和算法。设计并实现了基于TEEM架构的原型系统,原型系统的安全性分析和性能测试结果表明,TEEM能够为用户提供一个安全、稳定、高效的可信执行环境。     

基于TPM联盟的可信云平台管理模型

以可信计算技术为基础,针对可信云平台构建过程中可信节点动态管理存在的性能瓶颈问题,提出了基于TPM联盟的可信云平台体系结构及管理模型。针对TPM自身能力的局限性,提出了宏TPM和根TPM的概念。针对可信云中节点管理时间开销大的问题,引入时间树的概念组织TPM联盟,利用TPM和认证加密技术解决数据在TPM联盟内节点间的可信传输问题,提出了一种基于时间树的TPM联盟管理策略,包括节点配置协议、注册协议、注销协议、实时监控协议、网络管理修复协议和节点更新协议,阐述了时间树的生成算法,分析了建立可信节点管理网络的时间开销和节点状态监控的有效性。最后,通过仿真实验说明了模型具有较好的性能和有效性。     

可信计算平台可信计算基构建研究

对基于PC构建的可信计算平台中可信计算基的构建方式进行了分析,指出通过逻辑方式构建的可信计算基存在被篡改和绕过的可能性,并提出了一种基于密码技术构建可信计算基的方法。该方法以可信平台模块为信任根,验证可信计算基的完整性,防止可信计算基被篡改;将系统中受控可执行程序执行解释部分加密存放,密钥存放在可信平台模块,程序的执行必须通过可信计算基,防止了可信计算基被绕过。通过分析其基本原理,验证了基于密码技术可有效构建具备完整性和唯一性的可信计算基。     

一种可信计算平台及信任链传递验证方法

信任链是可信计算机系统的重要部分,它保证计算机系统从可信源头至系统各组件的可信,但存在信任链建立过程的信任度逐层衰减问题。文中通过可信平台控制模块授权CPU进行链式度量,同时TPCM尾随CPU对信任链进行实时的、随机的和分块的度量,然后在平台信任链中嵌入检查点,统计并检查各块运行时间,从而判断各信任节点是否被篡改。该方法提高了信任链建立和验证的实时性,尤其可以防御针对信任链的时间差攻击。     

A Trusted Smart Phone and Its Applications in Electronic Payment

With the growing intelligence and popularity of mobile phones, and the trend of cellular network＇s convergence to IP based network, more and more mobile applications emerge on the market. For mission critical applications, like the electronic payment which will be discussed in this paper, the lack of trust in the underlying mobile infrastructure and secure interface to legacy systems （for this case, the banking systems） poses obstacles to their widespread presence in mobile services. Recently, the exposure of hacking of iPhone and other smart phones further emphasizes the criticality of establishing a trust platform for mobile applications. This paper analyzes the building blocks of the trusted smart phone, and proposes a framework to provide a trusted platform for mobile electronic payment. Such a proposed system may allow direct interface to the banking systems due to the banking industry recognized strong security, and hence, may enable its widespread use.     

基于可信计算平台的认证机制的设计

身份认证是可信计算平台的基本功能。其中,平台必须能够向外部实体认证自己,让其它实体以确信系统是正确可信的。基于可信计算平台的认证机制设计的出发点是,在利用PKI认证机制的基础上,实现平台身份和平台状态的双重验证。身份认证证书（AIK）是认证实现的基础,可信CA是整个认证系统中的核心,负责所有可信计算平台的身份认证证书的颁发,同时描述了一套具体的基于可信计算平台的认证协议。     

基于用户卡的可信执行环境初始化方案

智能终端具备的可信执行环境在加载环节存在加载证书权威性问题.在分析可信执行环境(TEE)初始化架构和初始化方案的基础上,利用信任链技术,设计提出了将运营商用户卡作为可信根,进行智能终端可信执行环境初始化的方案,为电信运营商利用用户卡资源参与可信执行环境的产业链建设提供思路.     

Trust chain generating and updating algorithm for dual redundancy system

In trusted computing field,the traditional construction mode of trust chain is only applicable to a single system.For the dual redundancy system,it causes break of transitive trust.A trust model suitable for dual redundancy system was proposed.Through double trust chain design and IMC/IMV interaction mechanism,the trust chain extension of trust from a computing unit to another unit was realized.On this basis,a trust chain generating and update algorithm for dual redundancy system was proposed.Finally,the validity of the proposed model was proved based on the trusting theory.     

基于可信包装的可信软件构造模型

Since the guarantee of trustiness is considered inadequate in traditional software development methods, software developed using these methods lacks effective measures for ensuring its trustiness. Combining agent technique with the support of trusted computing provided by TPM, a trust shell based constitution model of trusted software (TSCMTS) is demonstrated, trust shell ensures the trustiness of software logically. The concept of Trust Engine is proposed, which extends the “chain of trust” of TCG into application, and cooperates with TPM to perform integrity measurement for software entity to ensure the static trustiness; Data Structure called trust view is defined to represent the characteristic of software behavior. For the purpose of improving the accuracy of trustiness constraints, a strategy for determining the weights of characteristic attributes based on information entropy is proposed. Simulation experiments illustrate that the trustiness of software developed by the TSCMTS is improved effectively without performance degradation.     

可信计算环境下的Canetti-Krawczyk模型

在可信环境下,我们对密钥协商协议的形式化方法—Canetti-Krawczyk(CK)模型进行研究,对该模型中定义的攻击者三种攻击能力重新进行分析.发现在可信环境下,如果用户的签名/验证公私钥对是由TPM生成的,则CK模型中的攻击者只有一种攻击能力:会话密钥查询(session-key query);否则攻击者有两种攻击能力:会话密钥查询和一种新的攻击能力—长期私钥攻陷攻击(long-term private key corruption).另外,TPM克服了CK模型中基于加密算法认证器的安全缺陷.在此基础上,我们提出了可信环境下的CK模型—CKTC.之后,通过一个使用CKTC模型进行密钥协商的例子可以看出该模型简化了可信环境下密钥协商协议的设计与分析.另外,通过分析我们发现:为了提高密钥协商协议的安全性,不同国家应该根据各自的需要在TPM内部增加对称加解密模块;用户的签名/验证公私钥对也尽可能由TPM来生成.     

云计算中动态可信平台模块的实现

针对目前在云计算环境中用户虚拟计算环境不可信的问题,利用可信平台模块虚拟化技术,在云服务器端为用户构造一个虚拟可信平台模块,然后以虚拟可信平台模块为基石,为用户在云服务器端构造了一个虚拟的可信计算环境,从而使现有的云计算用户中虚拟计算环境的可信情况获得了有效保障。通过与现有的可信平台模块虚拟化方案作对比发现,所提方案不仅周全地考虑了在云计算中虚拟机效率损耗的相关问题,而且相较显著提高了它的安全性和执行效率,更加适合被应用于用户虚拟计算环境。