During last few years, the demand of cloud computing has immensely arisen among the Corporate/Business organizations. The cloud computing concept brings exclusive monetary benefits to the corporate houses through its pay-as per use facility. The incurred cost only lies in the consumption of hardware and software resources for any particular available business applications [1].For any particular project, all the web applications are deployed on available physical servers ,dispersed throughout the countries ,connected through cloud service providers. This mega scale growth in the adoption of cloud platform leads to extreme revenue benefits to the involved parties. But at the same time, information security also requires to be well enveloped in the cloud environment [2].In this research work, we have incorporated various cryptographic algorithms to improve the authentication module such as Challenge response Authentication protocol and file data storage using suitable and efficient Digital Signature Standard scheme along with effective encryption schemes such as AES as well. The proposed framework represents proper client -server authentication and secured & trusted architecture for stored information on cloud server. We have done research work to alleviate the security of stored information with in the cloud and also to protect it from any outside attack during information exchange between client and server.