【作者】 余院兰；

【导师】 徐兰芳；

【作者基本信息】 华中科技大学 ， 信息安全， 2007， 硕士

【摘要】 信誉可有效地帮助双方维持可信的事务关系。信誉评估是规避风险最好的手段,可以迫使销售者提供最好的产品和服务,也可以避免消费者的欺诈行为,因此可作为买卖双方的一个重要信息参考中介。所以说,信誉评估系统是数字社会必不可缺的重要组件,信誉评估是建立在线信任、规避风险、减少不确定性的重要支撑技术之一。因此对信誉评估系统的深入研究有非常重要的现实意义。目前已有的信任评估模型倾向于采用基于一定的概率分布假设的事件概率方式来表述和度量信任关系,而且大多采用求简单算术平均的方法综合多个不同推荐路径的信任度,不能很好地解决恶意推荐对信任度评估的影响。因此针对信任评估的主观性、模糊性以及无法精确地描述和验证等问题,引出一个基于模糊数学的信誉评估系统,并给出了信誉评估算法。该算法能用直观、简洁的语义定量地描述信任值,反映了实体之间信任的模糊性,解决了关于模糊性实体之间的信任建模问题,适用于电子商务和电子政务领域。网络安全的主流技术是基于密码学的安全技术,如数字身份证书,但数字身份证书缺少的一个重要内容就是证书持有人的信誉。在证书中没有任何关于其过去行为的信息,而这些内容正是信誉系统所能提供的。信誉评估系统与数字证书的共同目标都是增强网络安全,减少风险,促进电子商务的发展。因此,可以将信誉评估与数字身份证书结合起来,并将信誉评估后的信誉值扩展为基于数字身份证书的属性证书的一部分,形成信誉属性证书,然后通过绑定信息与数字身份证书直接相关。这样认证中心既是数字身份证书的管理者,又可通过其查询到相应的信誉值。最后,给出了信誉评估和数字证书结合起来在电子商务中的应用协议。更多还原

【Abstract】 Reputation is the best means to avoid risks. It can force suppliers offer best products and services, and can also avoid the cheat of consumers. Reputation can maintain trust business relationship between them effectively. Reputation system is the necessary component of digital social. So the research of reputation system is of great importance.Currently, reputation system based on the assumption that the probability distribution of certain events and to express the probability metric the relation of trust, and mostly using the method of simple arithmetic average overall trust in a variety of recommended trails. It is unable to successfully resolve the impact of malicious recommendation. Because trust itself has objective and fuzzy, and we can’t descript and validate it exactly, we propose a reputation evaluation system based on fuzzy logic, give a reputation evaluation algorithm. The algorithm not only reflects the fuzzy of trust but also a visual and simple quantification description mechanism. It can apply in e-commerces and e-government.The dominating technology of network security is based on cryptogram, such as digital identity certification. What the identity certification lacks is the reputation of certification holder. There are nothing information about the history of the holder, and the reputation system does have. And the common goal of reputation system and identity certificate is enhancing network security, reducing risks and promoting the development of e-commerce. So the idea of combing the identity certification with reputation system is presented. The content of reputation is written in the attribute-item of attribute certification. The reputation attribute certificate is correlated with identity certification by the binding information. So, CA is not only the administrator of identity certifications, but the reputation also can be reviewed through CA. Finally, we discuss the application in e-commerce.更多还原