The wider adoption of cloud computing due to its inherent advantages also brings concerns of trust and security. Trust is a fundamental subject in human life. Although, several trust models exists in different areas including cloud, none of the trust models to-date are comprehensive enough to accommodate the characteristics of the cloud environment. This paper defines a trust model based on the essential cloud characteristics as the dimensions of the trust model together with several features relevant to the dimension to build the context. The proposed trust model is supported with an opinion model that considers uncertainty for building context specific trust and credibility complimented with early filtering to reduce the impact of malicous feedback providers. The proposed model is evaluated for its robustness against malicious feedback providers.