MMLT: A mutual multilevel trust framework based on trusted third parties in multicloud environments

In this article, a mutual multilevel trust framework is proposed, which involves managing trust from the perspective of cloud users (CUs) and cloud service providers (CSPs) in a multicloud environment based on a set of trusted third parties (TTPs). These independent agents are trusted by CUs and CSPs and distributed on different clouds. The TTPs evaluate the CUs' trustworthiness based on the accuracy of feedback ratings and assess the CSPs' trustworthiness based on the quality of service monitoring information. They are connected themselves through the trusted release network, which enables a TTP to obtain trust information about CSPs and CUs from other clouds. With the objective of developing an effective trust management framework, a new approach has been provided to improve trust-based interactions, that is, able to rank the trusted cloud services (CSs) based on CU's priorities via fuzzy logic. Fuzzy logic is applied to manage the different priorities of CUs, all the CUs do not have the same priorities to use trusted CSs. Customizing service ranking allows CUs to apply trusted CSs based on their priorities. Experiments on real datasets well matched the analytical results, indicating that our proposed approach is effective and outperforms the existing approaches.     

基于双重完整性的可信证明模型

传统可信远程证明方法对于动态证明问题描述不足,且在可信证明过程中,证明主/客体交互行为对于可信性的影响缺乏理论依据。为此,提出一种基于证明主/客体双重完整性的可信证明模型,在该模型中引入可信性概念,定义可信属性及可信状态的建立规则,根据该模型设计可信证明系统,并分析主/客体不同完整性的证明方法。     

基于法予权利权利义务模型的可信计算环境实现

针对目前对信任的定义和模型没有尚未建立通用表达的研究现状问题,提出了一种基于现有计算机网络的可信计算平台模型,该模型充分利用了现有的计算机及其网络平台的通用性,提出一个可信计算平台模型。通过把现有的计算平台分层逻辑化为不同的信任层,降低了可信计算平台模型实施的难度,提高了其灵活性、扩展性和效率。,同时该模型从在客户端系统的引导阶段出发构建完整的可信链,以保证了可信计算平台的安全性。原型系统的实现的结果表明：由于,系统中所有的计算机及其网络构成统一的可信计算平台,使信任的传递从用户到用户,进而实现真正的对于用户体验间的可信计算。     

A trust-based service suggestion system using human plausible reasoning

Nowadays, there is a growing need to manage trust in open systems as they may contain untrustworthy service providers. Agent Trust Management (ATM) tries to address the problem of finding a set of the most trusted agents in multi agent systems. This paper presents ScubAA, a novel generic ATM framework based on the theory of Human Plausible Reasoning (HPR). For each user’s request, ScubAA determines a ranked list of the most trusted service agents, within the context of the request, and forwards the request to those trusted services only. ScubAA determines an agent’s degree of trust in terms of a single personalized value derived from several types of evidences such as user’s feedback, history of user’s interactions, context of the submitted request, references from third party users as well as from third party service agents, and structure of the society of agents. ScubAA is able to utilize more trust evidences towards a more accurate value of trust. We also propose a function to figure out how similar two users are in a given context. We apply the proposed HPR-based ATM framework to the domain of Web search. The resulting ATM system recommends to the user a list of the most trusted search engines ranked according to the retrieval precision of documents returned in response to the user’s query as well as the degree of trust of the search engines have gained by interacting with other related users within the context of the query. In addition, we conduct a statistical analysis of ScubAA based on ANOVA and by using a data set of forty queries in different domains. This analysis clearly reveals that ScubAA is able to successfully assess the trustworthiness of service agents.     

一种基于行为证明的主观动态可信模型建立方法

在分布式环境中如何在实体之间建立信任关系一直是信息安全领域研究的热点问题,远程证明为解决该问题提供了一种新的研究方向。远程证明是可信计算中非常重要的特性,利用可信远程证明方法能够在实体之间建立起信任关系。但是,二进制等静态远程证明方法对于计算平台的可信性证明存在明显不足,在建立信任关系时不能够提供充分的证据。主要研究基于行为证明方法在实体之间如何建立可信关系的问题。因此,利用基于行为的远程证明方法对计算机平台可信性进行证明,该方法能够为建立信任关系提供更加准确的经验结果。在证明过程中存在一些不确定因素,这些不确定因素将影响信任关系的建立以及评估。利用主观逻辑对信任关系进行了度量,建立了TMBA动态可信模型,该模型能够在基于行为证明所获得的经验的基础上,通过考虑过去经验以及现有经验分析信任关系的动态性,并且将信任关系中的信任度用主观逻辑的观点来表示。最后给出根据TMBA对信任观点进行计算的方法。     

带有激励机制的车联网合作下载信任管理方案

由于高速公路上行驶的车辆间未预先建立信任关系，车辆相互进行合作下载服务时，存在信任危机及安全隐患，严重影响合作下载的发展。为实现可信任的安全合作下载服务，提出基于SORT算法的信任管理方案，通过服务信任值选择合适的车辆进行合作，设计激励机制和公平交易协议保证合作下载的积极性和公平性，应用区块链技术对车辆的身份隐私以及数据信息进行存储和保护。分析结果表明，该方案能够使用户选择可信任的车辆进行安全的合作下载服务，促进车辆用户下载效率的提高。     

分级的软件可信评估模型研究及应用

针对软件的可信任问题,展开对软件可信程度的度量和评估的研究,提出了软件质量模型及分级的可信软件评估模型,将软件的信任程度分为存在级、不可信级、可用级、证实级、推荐级、应用级等6个可信级别。基于决策树给出了可信软件等级的评估过程,并将其应用于可信构件平台中。经过测试,系统运行稳定,对高可信软件的开发和重用具有引导作用。     

云环境中可信虚拟平台的远程证明方案研究

云环境中如何证明虚拟平台的可信,是值得研究的问题.由于云环境中虚拟平台包括运行于物理平台上的虚拟机管理器和虚拟机,它们是不同的逻辑运行实体,具有层次性和动态性,因此,现有的可信终端远程证明方案,包括隐私CA （privacy certification authority,简称PCA）方案和直接匿名证明（direct anonymous attestation,简称DAA）方案,都并不能直接用于可信虚拟平台.而TCG发布的Virtualized Trusted Platform Architecture Specification 1.0版中,可信虚拟平台的远程证明方案仅仅是个框架,并没有具体实施方案.为此,提出了一种自顶向下的可信虚拟平台远程证明实施方案——TVP-PCA.该方案是在虚拟机中设置一个认证代理,在虚拟机管理器中新增一个认证服务,挑战方首先通过顶层的认证代理证明虚拟机环境可信,然后通过底层的认证服务证明运行于物理平台上的虚拟机管理器可信,顶层和底层证明合起来确保了整个虚拟平台的可信,有效解决了顶层证明和底层证明的同一性问题.实验结果表明,该方案不仅能够证明虚拟机的可信,而且还能证明虚拟机管理器和物理平台的可信,因而证明了云环境中的虚拟平台是真正可信的.     

一个适用于网构软件的信任度量及演化模型

网构软件的构建依赖于对开放协同环境中各种异构的、自治的软件服务实体间的有效协同.Internet的开放性与动态性,使得对于诚实的、具有可靠服务质量协同实体的选择难度较大,难以确保网构软件的可信性.软件实体间的信任关系对于保障网构软件的可信性具有重要的指导意义.软件实体间的信任关系通常随协作的进行而不断变化,但现有的信任模型缺乏对实体间信任关系的自动形成与更新的支持,从而无法刻画信任关系的动态性.针对该问题,提出了一个适用于网构软件的信任度量及演化模型.该模型不仅对信任关系度量过程和信任信息传递及合并过程进行了合理抽象,而且还提供了一种合理的方法,用于促进协同实体间信任关系的自动形成与更新.该模型有助于解决开放环境下网构软件的可信性问题.     

Qualitative trust model with a configurable method to aggregate ordinal data

Trust models are mechanisms that allow agents to build trust without relying on a trusted central authority. Our goal was to develop a trust model that would operate with values that humans easily understand and manipulate: qualitative and ordinal values. The result is a trust model that computes trust from experiences created in interactions and from opinions obtained from third-party agents. The trust model, termed qualitative trust model (QTM), uses qualitative and ordinal values for assessing experiences, expressing opinions and estimating trust. We treat such values appropriately; we never convert them to numbers, but merely use their relative order. To aggregate a collection of such values, we propose an aggregation method that is based on comparing distributions and show some of its properties; the method can be used in other domains and can be seen as an alternative to median and similar methods. To cope with lying agents, QTM estimates trustworthiness in opinion providers with a modified version of the weighted majority algorithm, and additionally combines trustworthiness with social links between agents; such links are obtained implicitly by observing how agents provide opinions about each other. Finally, we compare QTM against a set of well-known trust models and demonstrate that it consistently performs well and on par with other quantitative models, and in many cases even outperforms them, particularly when the number of direct experiences is low.     

基于UEFI的可信BIOS研究与实现

分析固件基本输入输出系统(BIOS)的安全需求,定义了可信BIOS概念。基于UEFI规范和可信计算机制设计UTBIOS体系结构。UTBIOS的实现以新一代符合UEFI规范的BIOS产品为基础,使用可信测量根核对BIOS运行和系统引导过程中各部件进行可信测量,构建操作系统运行前的可信链,讨论可信测量对BIOS引导过程的性能影响。     

两层市场环境中信任感知的资源交易机制

在以往建立信任团体时,假设一个节点只拥有一种类型的资源,但在实际的网格市场中,一个节点可以拥有多种资源.资源提供者有效地分配这些资源以获得收益,资源使用者为完成特定任务需要从多个节点获得多种资源.为解决此情况下信任框架的建立问题,本文将信任机制融入两层市场(资源市场和服务市场)的资源交易模型中,在改进信任团体建立方法的同时,提出了基于两层市场的资源交易机制.     

Comparative trust management with applications: Bayesian approaches emphasis

Trust relationships occur naturally in many diverse contexts such as collaborative systems, e-commerce, interpersonal interactions, social networks, and semantic sensor web. As agents providing content and services become increasingly removed from the agents that consume them, the issue of robust trust inference and update becomes critical. There is a need to find online substitutes for traditional (direct or face-to-face) cues to derive measures of trust, and create efficient and robust systems for managing trust in order to support decision-making. Unfortunately, there is neither a universal notion of trust that is applicable to all domains nor a clear explication of its semantics or computation in many situations. We motivate the trust problem, explain the relevant concepts, summarize research in modeling trust and gleaning trustworthiness, and discuss challenges confronting us. The goal is to provide a comprehensive broad overview of the trust landscape, with the nitty-gritties of a handful of approaches. We also provide details of the theoretical underpinnings and comparative analysis of Bayesian approaches to binary and multi-level trust, to automatically determine trustworthiness in a variety of reputation systems including those used in sensor networks, e-commerce, and collaborative environments. Ultimately, we need to develop expressive trust networks that can be assigned objective semantics.     

一种P2P网络服务环境的信任度计算模型

首先依据新实体能力属性给出了初始信任度计算算法,然后根据实体的直接交互满意度与其他信任实体的推荐信息,设计了直接信任度和推荐信任度计算算法。综合三种信任度,提出了信任度计算模型。该模型为网络实体间信任关系的建立和信任行为的决策提供了有力依据,从而减少实体交互风险,提高网络运行稳定性。     

基于交互式马尔可夫链的可信动态度量研究

可信动态度量为保障可信计算平台的可靠运行提供了重要支撑.根据系统的可靠性、可用性、信息和行为安全性,提出了可信度量要达到的目标.当前的可信度量集中在可信功能度量上,基于交互式马尔可夫链增加性能特征指标度量,即在预期行为描述模型中,运用变迁系统模型描述功能预期,通过将体现在可靠性上的路径概率与预期的关联,获取完成特定行为...     

基于分布式可信度量的移动代理安全应用模型研究

本文主要讨论了可信计算平台上的移动代理安全方案。利用可信计算平台提供的可信度量策略与信任链机制,构建基于可信度量的移动代理安全体系结构。进一步地,在此类平台所构成的移动代理分布式计算环境中,建立了移动代理平台间基于可信度量的信任关系数学模型,并进行了数值模拟与测试验证。     

Linux可信引导技术研究

可信计算对于信息系统的安全需求,提出了新的计算机系统安全解决方案,成为目前安全领域的研究热点.提出基于可信平台模块TPM(Trusted Platform Module)的Linux引导技术,阐述Linux引导模块之间信任链的建立及完整性度量的方法.任何模块加载执行之前必须通过完整性度量才能获得控制权,远程系统通过完整性度量值验证引导过程是否真实可信.     

网站可信标识架构与查验协议研究

高可信性是下一代互联网的重要特征,主要包括服务提供者可信、信息传输可信和终端用户可信,其中服务提供者的身份可信是构建可信网络的前提。为此,提出一种网站身份可信标识的体系结构,描述基于域名资源记录的网站可信标识查验协议。通过该协议,用户可在各种互联网应用中方便地查询服务提供者的身份信息。实验结果表明,该体系结构与相关查询协议在效率、易用性、可扩展性等方面均可满足实际应用需要,单机查询性能达到15万次／s。     

基于精确分类和最优匹配机制微电网交易决策方法

随着国家对电力市场改革的不断推进和售电市场的优化,微电网将成为未来电能发展和电网运营管理改革的重要载体。为了提升产消者和消费者的订单匹配效率以及经济效益,首先提出了一种基于区块链技术的微电网电能安全交易,利用双链完成交易双方信息的认证,并提出基于Shapley值分配合作博弈的定价策略。其次,对参与微电网交易的消费者进行精确分类,提高订单交易匹配效率。再次,在订单交易阶段提出基于总优先指数的匹配满意度函数,建立满意稳定的微电网交易双边匹配模型。最后,交易双方通过智能合约完成无第三方信任机构的交易结算。算例结果表明,基于区块链技术和最大满意度及稳定性的微电网交易方法可以完成微电网内部的直接交易,保证了微电网交易的稳定性,并提高了参与微电网交易双方的满意度及匹配稳定性。     

贸易信用下考虑零售商违约风险的供应链协调问题研究

本文研究延迟支付和提前支付同时存在下的供应链协调问题。考虑由一个供应商和一个零售商构成的二级供应链,市场需求随机,延迟支付下零售商会增加订购数量,但由于其违约风险的存在,供应商会降低其交付量,最终导致供应商交付量小于零售商订购量,降低供应链收益。要求零售商提前支付部分货款则可以有效避免零售商的违约问题,通过建立延迟支付和提前支付同时存在下的零售商收益模型和供应商的收益模型,给出了零售商的最优订购量决策和供应商的最优交付量决策,通过调整延迟支付期限和提前支付比例,使得二者相等,并等于供应链整体收益最大化下的生产数量,实现供应链协调。最后通过数值算例分析了相关参数的敏感性等问题。