The Research Of Trust Evolution Model For Cloud Services

Cloud computing, evolved from Internet, is an emerging business computing mode which can access to share resources anytime, and anywhere. It has been widely seen as one of the fifth generation of computing technology. It is also known as a service-based computing. Cloud computing apply "service providers" and "user" separation of business model to provide services for users. It uses virtualization technology to provide wealthy information in the cloud to customers.Cloud computing is still in the preliminary development stage. Various manufacturers are developing different types of cloud computing services. Now, major form of service contains three categories:software as a service (SaaS), Platform as a Service (PaaS) and infrastructure as a service (IaaS). The major manufacturers providing the three types of services are Google, Amazon, IBM and Microsoft, also there are many emerging small and medium-sized companies. So there are a wide variety of clouds services appearing in the market whose quality vary a lot. How to ensure the security of these cloud services has become a particular concern, but also become barriers to popularize and promote cloud computing. To establish an effective and reliable trust management mechanism is an important means to solve the cloud security. There are many scholars began to study the issue of trust in cloud computing. Their study is in its infancy. Based on the characteristics of cloud services, this paper conducts a deep study and discussion on the evolution of trust between the two sides of cloud services transactions.Start from the trust relations theory of interpersonal community, this paper build a cloud service-oriented trust evolution model by summarizing previous studies of dynamic trust model and combing the characteristics of cloud services. By introducing the modular idea, the model divides the evolution of the trust relationship between the cloud services transactions parties into three modules, namely trust initialization module, trust evaluation module and service satisfaction evaluation module. The model combines the service time and the service amount and other factors to calculate the direct trust values in the trust relationship and use behavioral similarity theory to calculate indirect trust value. After getting the list of trusted cloud service providers, the paper chooses the best trusted cloud service providers by combing QoS attributes of the cloud service provider and using TOPSIS law. Finally, according to the characteristics of cloud services, assess the transaction parties mutually and update the trust value of both sides dynamically to complete the trust dynamic evolution process. By designing and implementing simulation experiments to analyze the model, the experiments’results prove that the model has high validity and reliability.