Trust and distrust on the web: User experiences and website characteristics

The aim of this research is to study the content of trustful and distrustful user experiences on the web to identify website characteristics that enhance trust or cause distrust. We collected users’ reports about critical incidents and quantitative questionnaire data by means of an online survey. Results from N = 221 participants suggest that distrust is mostly an effect of graphical (e.g., complex layout) and structural (e.g., pop-ups) design issues of a website, whereas trust is based on social factors such as reviews or recommendations by friends. The content of a website affects both trust and distrust: privacy issues had an effect on distrust and security signs enhanced trust. Furthermore, we show how trustful and distrustful user experiences differ in terms of perceived honesty, competence, and benevolence. High honesty and competence characterize a trustful experience, whereas a distrustful experience is associated with missing honesty and missing benevolence. We discuss how different website characteristics help to enhance trust or to prevent distrust and how this impacts the allocation of design resources.     

基于信任和时间约束的访问控制模型TTRBAC

在分析基于信任的访问控制模型TrustBAC及模型中信任级计算方法的基础上,提出在信任级计算中引入了时间因素后的TTRBAC模型,给出了时间因素影响信任级的计算方法.新模型把用户在线时长作为影响用户信任级的重要因素,提高了模型的描述能力.     

Trust management towards service-oriented applications

In service-oriented computing (SOC) environments, service clients interact with service providers for services or transactions. From the point view of service clients, the trust status of a service provider is a critical issue to consider, particularly when the service provider is unknown to them. Typically, the trust evaluation is based on the feedback on the service quality provided by service clients. In this paper, we first present a trust management framework that is event-driven and rule-based. In this framework, trust computation is based on formulae. But rules are defined to determine which formula to use and what arguments to use, according to the event occurred during the transaction or service. In addition, we propose some trust evaluation metrics and a formula for trust computation. The formula is designed to be adaptable to different application domains by setting suitable arguments. Particularly, the proposed model addresses the incremental characteristics of trust establishment process. Furthermore, we propose a fuzzy logic based approach for determining reputation ranks that particularly differentiates new service providers and old (long-existing) ones. This is further incentive to new service providers and penalize poor quality services from service providers. Finally, a set of empirical studies has been conducted to study the properties of the proposed approaches, and the method to control the trust changes in both trust increment and decrement cases. The proposed framework is adaptable for different domains and complex trust evaluation systems.

一种改进的基于向量的P2P电子商务信任模型

在交易之前通过信任模型帮助交易对象之间建立信任关系,是P2P电子商务发展的必要条件,也是近年来的研究热点。本文针对现有模型的不足,在基于投票协议的P2P电子商务安全信任模型的基础上,引入了向量表示信任,并且在权限的确定、信任的表述和信任的评估等多方面做了改进。经过模拟实验和分析证明,改进后的模型不仅可以让用户根据各自的不同要求对交易对象做出更合理的信任评估,而且能快速识别和隔离恶意节点,从而降低了交易风险。     

分布式信任模型直接信任的模糊计算方法

在电子商务、数据通信和网络安全等应用系统中,信任模型是不可缺少的基本机制。但是对于Ad—hoe网络,Peer-to—Peer网络等分布式系统,由于不存在集中专用的服务器,传统的信任模型无法被采用。本文分析了保证分布式信任模型有效性的关键因素,提出了一种新的直接信任模糊计算方法,仿真数据表明,新方法比传统方法更准确。     

A trust negotiation system for digital library Web services

A scalable approach to trust negotiation is required in digital library (DL) environments that have large and dynamic user populations. In this paper we introduce Trust-Serv, a model-driven trust negotiation framework for Web services, and show how it can be used to effectively handle trust negotiation in DLs. The framework employs a model for trust negotiation based on state machines, extended with security abstractions. High-level specifications expressed with the state-machine-based model are then translated into formats suitable for automating the trust negotiation process. The proposed framework also supports negotiation policy lifecycle management, an important trait in the dynamic environments that characterize DLs. In particular, we present a set of policy change operations that enable the dynamic evolution of negotiation policies without disrupting ongoing negotiations. The proposed approach has been implemented as a container-centric mechanism that is transparent to the DL and to the developers of DL Web services, simplifying DL development and management as well as enabling scalable deployments.     

Extracting trust information from security system of a service

The issue of trust is a research problem in emerging open environments, such as ubiquitous networks. Such environments are highly dynamic and they contain diverse number of services and autonomous entities. Entities in open environments have different security needs from services. Trust computations related to the security systems of services necessitate information that meets needs of each entity. Obtaining such information is a challenging issue for entities. In this paper, we propose a model for extracting trust information from the security system of a service based on the needs of an entity. We formally represent security policies and security systems to extract trust information according to needs of an entity. The formal representation ensures an entity to extract trust information about a security property of a service and trust information about whole security system of the service. The proposed model is applied to Dental Clinic Patient Service as a case study with two scenarios. The scenarios are analyzed experimentally with simulations. The experimental evaluation shows that the proposed model provides trust information related to the security system of a service based on the needs of an entity and it is applicable in emerging open environments.     

基于Skyline的动态可信服务选择方法

服务选择是实现服务共享、组合、复用的重要前提。随着具有相同功能属性但非功能属性(如服务质量C Quali- ty of Scrvicc, QoS))不同的候选服务数量日益增多,QoS已成为服务选择的关键指标。然而,在动态网络环境下,服务 选择过程中QoS数据的真实可信性无法得到保障。通过引入包括度量服务资源种类及服务提供商信任的服务信任 ( Trust of Scrvicc, ToS)来构建服务的信任机制。利用Skyline技术的支配关系及投影模型,给出QoS和"hoS两者之 间的关联,提出了基于Sk沙nc的动态服务选择算法,它在确保服务质量的前提下可提高服务选择的可信性。仿真实 验表明了所提算法的可行性与有效性。     

面向个性化需求的云制造服务可信评价模型

针对传统的云制造服务可信评价模型中存在的可扩展性弱、难以满足个性化需求等问题,提出一种可扩展性强、可以较好地满足个性化需求的可信评价模型.首先构建多层次的、多粒度的云制造服务可信评价框架;然后基于此框架,提出了基于云模型的云制造服务可信评价方法,在该方法中,引入云模型理论,用于统一表征不同类型的评价指标,以及描述用户的...     

基于性能量化矩阵的计算网格作业调度算法研究

提升计算网格系统运行效率的关键在于作业调度算法,如何综合各种因素使得调度策略更为全面是一个有挑战性的问题.通过建立网格资源性能量化矩阵,构建了一个作业调度模型,并基于此模型给出了一个具体的作业调度算法.通过性能分析和实验仿真,该算法在运行时间、占用资源等方面都有较大的改善,能较好地适应网格系统的动态性和可扩展性特点,提高了作业调度效率.