Cloud Service Selection based on the Credibility persistency of Users’ Feedbacks

Nowadays, trust is a major topic under discussion in the cloud computing environments. The existence of a mechanism for building and preserving trust among service consumers and providers is a critical component in the success of providing cloud services. Therefore, computational trust in cloud computing environments has turned into a considerable concern. The lack of trust among service providers and consumers may result in the reduction of the general appeal for the acceptance of cloud services among users. In other words, even though the services provided by each vendor maybe similar in terms of functionality, they may vastly differ in terms of quality of service. For this reason, a false choice in selecting a service may have devastating impacts on the requirements and goals of the end-user. To this aim, in this paper, a computational trust model based on the credibility of users’ feedbacks for the calculation of services’ trustworthiness is introduced. The proposed model, not only takes into account the existing experiences that other users have with a service provider, but also considers the credibility of such feedbacks as well as the persistency of correct and constructive feedbacks through time. In the end, the efficiency of the proposed model is investigated through a series of evaluation scenarios and it is shown that the proposed model is capable of accurately calculating the trustworthiness of the system. Such accuracy is maintained even in the presence of malicious users.