云环境下基于IFAHP的用户行为信任模型研究

摘要

In cloud computing environment, user behavior will cause security problems. Considering the randomness and fuzziness of these security problems, the paper proposes a model for evaluating the reliability of the user in the use of cloud services by using the intuitionistic fuzzy analytic hierarchy process (IFAHP). In this model, the user behavior is decomposed into several factors according to the hierarchical decomposition. By comparing the degree of priority, the degree of non priority and the degree of uncertainty among factors, the initial judgment matrix given by the expert or decision maker is amended. Thus, a more reasonable judgment matrix is obtained, which reduces the subjective inlfuence of the cloud service provider and decision maker on analysis. The weight of each factor is gradually determined, and the objectivity and quantitative characteristic of the factor are improved. The user behavior trust value is obtained by the model calculation and different authority is given to user according to different trust level, which reduces the impact of the user on cloud environment security. Experimental results show that the model can effectively detect the malicious users in the cloud environment, and improve the security of the cloud environment.%云计算环境下，用户行为会对云环境造成安全问题。考虑到这些安全问题所具有的随机性和模糊性，结合可信云的思想，文章提出利用改进后的层次分析法进行建模，实现采用基于主观推断模糊层次分析法（IFAHP）的模型评价用户在使用云服务时行为的可信程度。该模型将用户行为按层次分解为若干因素，通过比较因素之间的优先程度、非优先程度以及不确定性程度，修正了决策者、专家给出的初始判断矩阵，从而得到更为合理的判断矩阵，减少了云服务提供商和决策者在分析时的主观影响；逐步确定各因素的权重，提高了因素的客观性和量化特性；通过模型计算得到用户行为信任值，通过信任等级赋予用户不同的权限，降低用户对云环境安全的影响。实验结果表明，该模型能够有效检测出云环境中的恶意用户，提高云环境的安全。