【作者】 董宇欣；

【导师】 印桂生；

【作者基本信息】 哈尔滨工程大学 ， 计算机应用技术， 2011， 博士

【摘要】 近几年,对网构软件可信性的研究成为学术界研究的热点,网构软件的出现给现有的软件技术研究提出了新的课题,现有的软件理论、方法和相应的中间件平台技术体系难以有效地适应网构软件这种新的形态。在软件理论与模型方面,传统软件理论与模型难以描述计算单元的分布、自治和异构性,以及计算单元间协同、交互的开放、动态和演化特性；在软件方法与技术方面,传统方法难以适应网构软件的协同性、自适应性,以及需求的多目标性；而在软件可信性(可靠性与安全性)方面,传统软件方法与技术体系难以适应开放环境所要求的整体。网构软件系统需要一种动态演化的、相对“柔性”的可信保障机制。信任机制的建立可有效提高网构软件系统的可信性,在网构软件信任系统中,实体通过选取信任度高的实体进行协作,即只允许高信任度的实体访问自身提供的服务,有效地避免free-riding问题的产生,从而达到提高网构软件系统整体可信性的目的。在进行网构软件信任机制的研究时,必须全面考虑网构软件可能面对的来自需求、环境等方面的变化,并设计相应的处理措施,使网构软件具备足够的反应性。基于网构软件的以上特征,本文的研究内容包括以下几个方面：(1)研究网构软件的信任机制,包括信任机制的描述、分析及逻辑推理。基于信念逻辑及信任关系,结合PKI模型实例对信任链建立过程进行描述与推演。提出一种基于贪心策略寻找最优信任链搜索算法GSTC和多路径信任聚合算法MPTA,以避免置信度较差的节点通过信任链传播到整个网络,控制恶意信任链的传播,并减少信任评估过程中的计算开销和网络负载。(2)针对多维信任属性的度量与评估机制,研究网构软件可信属性之间的交互关系及可能涌现的特征。提出一种历史实例数据和信任属性相结合的动态信任度量方法,通过获取多维属性的高信任度的相似构件集合,来合理评价和选择网构软件实体,以提高整个网构软件系统的信任水平。(3)根据网构软件演化过程具有选择遗传特征,提出一种基于Wright-Fisher的网构软件信任演化模型；基于网构软件实体信任行为的特性,提出一种基于逻辑斯蒂方程的网构软件自组织信任演化模型。从不同的角度对系统的信任演化趋势进行预测分析,并且对网构软件系统的演化方向及稳定性进行分析,建立相应的激励惩罚机制,以提高网构软件系统整体的信任水平。(4)基于对信任的合并、传递以及决策,提出一种基于惩罚机制的网构软件信任评估方法,以提高系统抵抗恶意攻击的能力。由于信任关系经信任网络中传递合并后可能会产生无效的信任信息,本文借鉴了RIP路由算法思想给出一种获得信任网络信任有效信息的算法,并通过实验验证其有效性和可靠性。(5)针对网构软件运行过程中的构件故障问题,以静态博弈为分析工具,探索网构软件的在线维护最优策略选择方法。提出一种能够模拟构件故障演化态势,具有依赖关系和维护过程特征的在线维护博弈模型；研究在具有依赖关系的两实体发生故障的情况下,采取各种维护策略所获得的综合收益的计算方法,并对该方法进行推广,使其适用于更普遍的多构件故障维护中策略的选择问题。本文从网构软件的基本特征出发,以开放网络的动态演化为基础,结合生物学、社会学等领域的相关知识,对网构软件信任机制、信任度量、信任演化模型、信任评估以及博弈策略展开研究,为网构软件在动态演化环境中的信任机制建立系统的信任演化模型。更多还原

【Abstract】 In recent years, the study on trust technology of Internetware has been a research hotspot in academic world. The appearance of Internetware puts forward a new subject for the existing software technology. The existing software theory, methods and corresponding middleware platform technology are hard to adapt the new software paradigm. In the aspect of software theory and model, traditional software theory and models are difficult to describe the distribution, autonomy and heterogeneity of the calculating units, nor could they depict the open, dynamic and evolutional characteristics among calculating units in cooperative interaction. In respect of software methods and techniques, traditional methods are hard to adapt the cooperativity and self-adaptiveness of Internetware, and the multi-objectiveness of requirements. Furthermore, with regard to software trustworthiness (reliability and security), traditional approaches and technologies are hard to accommodate the entirety of the open environment.Internetware needs a dynamic, evolutional, relatively flexible and dependable safeguard mechanism. The credibility of Internetware system could be increased via the construction of trust mechanism. In such systems, entities tend to select those with high credibility to cooperate, that is to say, each only allows the entities with high credibility to access its own services in order to effectively avoid the phenomenon of free-riding and enhance the overall trust level of Internetware system. While studying on trust mechanism of Internetware, the variability that Internetware may encounter from requirements, environments, etc, should be taken into account and meanwhile corresponding countermeasures should be designed, so as to make Internetwares be equipped with sufficient reactivity. Based on the above characteristics of Internetware, this paper makes research in the following aspects.1. The trust mechanism of Internetware is studied, including description, analysis and logical reasoning. Based on belief logic and trust relationship, combined with an instance of PKI model, the description and deduction of the building process of trust chain is given in the paper. An optimal search algorithm of greedy strategy for trust chain (GSTC) and multipath trust aggregation algorithm (MPTA) are proposed, so as to prevent the nodes with relatively low credibility being spread to the whole network through trust chain, control the spread of malicious trust chain, and reduce the calculating cost and network load in the process of trust evaluation.2. With respect of measurement and evaluation mechanism of multidimensional trust properties for Internetware, the interactions between trust properties and the potential characteristics that may emerge are studied. A dynamic trust measurement approach conjoining historical data and trust properties is proposed, so as to evaluate and select Internetware entities reasonably and increase the overall trust level of the Internetware system via acquiring similar components set with high credibility of multidimensional trust properties.3. On the basis of the selective and hereditary properties of evolutional process of Internetwares, a trust evolution model of Internetware based on the Wright-Fisher is proposed. Meanwhile, according to the trust behavior characteristics of Internetware entities, a self-organizing trust evolution model of Internetware based on Logistic equation is put forward. The trust evolutional trend of Internetware is analyzed and forecasted from different angles, and the evolution direction and stability of Internetware system are analyzed. Furthermore, the corresponding incentive and punishment mechanism is established, so as to improve the whole trust level of Internetware system.4. On account of the trust combination, transmission and trust decision, a trust evaluation method of Internetware based on punishment mechanism is proposed, so as to improve the system’s capability to resist malicious attacks. As invalid information may be generated through the process of transmission and combination of trust, an algorithm based on the idea of RIP route algorithm is proposed in the paper in order to achieve valid trust information. And its effectiveness and dependability are proved via experiments.5. In terms of the troubleshooting problem of Internetware components in their running process, using static game as analysis tool, the optimal strategy selection method of online maintenance for Internetware is explored. A kind of online maintenance game model with dependent relationship and characteristics of maintenance process, which could simulate the evolution tendency of component faults, is proposed. In the case of two broken-down entities with dependent relationship, the calculation method for obtaining the comprehensive income of adopting different maintenance strategies are researched, and then the method is extended to be applicable to the strategy selection of more pervasive troubleshooting problems for multiple components.To start with the basic characteristics of Internetwares, based on the dynamic evolution for open network, combined with the relevant knowledge in the field of Biology and Sociology, the trust mechanism, trust measurement, trust evolutional model, trust evaluation, and game strategy are studied in the paper. And then systematic evolutional models are established for trust mechanism in evolutional environment.更多还原