Cloud computing has played much important role in comparison to other fields of IT, in providing Data storage, Data security, Quality of Services (QoS) etc. In the last few years, it had emerged and evolved so quickly due to its number of facilities and advantages to the organizations and end users. Many data security factors have also increased due to this fast evolution of cloud in the IT industry. Therefore several security models and trust establishing techniques have been deployed and are been in execution for providing more security to the data, especially the sensitive data. Despite of that much security, many of the models/techniques lacks in one or more security threat measures. In this paper a new model have been designed and proposed which introduces Security Aware Cloud. First the trust of the user or organization is established successfully on cloud than the security to the data is granted through privacy and encryption module. Level of quality of service and security are achieved under the Contract Trust layer while the Authentication and Key Management are covered under Internal Trust layer. For critical data privacy and encryption, Homomorphism mechanism is used. By the use of proposed trust and security model, we can enhance Return on Investment factor in the cloud for the data security and service provided by it.