Abstract

Cloud computing is the most discussed research area now-a-days which helps to provide flexibility and elasticity in using the computing properties and services to fulfill the condition of current companies. Cloud computingdeals dynamic, shared services, scalable and cost-effective for enterprises from distant data center. However, the problem of trusting the cloud computing is a supreme concern for enterprises as trust is widely regarded as one of the top problems for the approval and development of cloud computing. It deals with many obstacles in the path of its growth, that are security issues, data privacy issues and distrust on Cloud Service Providers (CSP). To achieve this, trust should be established between CSP and Cloud Consumer (CC). There are a lot of methods proposed to help the consumers identify the cloud service provider who seems to be more reliable. Authentication based trust models use encryption and key management technologies to establish trust between CCs and CSPs. This category includes trust models that ensure the availability, integrity and confidentiality of data on cloud by using certificates from standardized body, trust tickets, private and public keys, Tested Platform Module (TPM) endorsement keys and etc. This paper addresses the existing trust models for trust establishment in cloud services and also tries to find out the shortcomings of these models. Trust models are measured as a methodology that aids to estimate trust on the CSP’s or the third party suppliers that are providing the cloud services.