Now a days everywhere talking about cloud computing paradigm and if you look at business enterprises there are lot of initiatives to put everything on a cloud computing . Most of the IT industries are insisting to adopt cloud computing in their business operations. A Cloud Computing is a one infrastructure which can cater to the need of many people and it can do different varieties of services and functionalities such as ,it can store for you, it can compute for you, importantly it can scale for your need, so cloud computing means a provision of infrastructure which is scalable and it can do different varieties of services. A major challenge today in providing cloud computing is data security, access control and privacy of users data, so first we need to identify what are the security issues, security threats and security vulnerabilities present in cloud computing ,after identifying and analyzing all these issues we have to propose a solution model which will provide data security ,access control and data privacy in cloud computing. Information security is one of the significant imperatives for re-appropriated information in a distributed storage condition. This paper addresses key concerns that are presumed to have long haul pertinence to distributed computing security and protection on the basis of established concerns and vulnerabilities. The main aim of this paper is to highlight key security , privacy and trust concerns in current cloud computing environments and to help users understand the tangible and intangible risks associated with their use, including those associated with cloud computing. (a)Survey the most important protection, security and trust gives that present dangers to current distributed computing conditions and (b) Analyze how these possible risks to privacy , security and confidence can be handled and provide a high level of security, confidence and reliability in the cloud computing world. In the near future, we will further examine and evaluate privacy, protection and trust problems in the cloud computing environment through a quantifiable methodology, further build and deploy comprehensive security, privacy trust assessment, management system for truly cloud computing environments.

Keywords : Access Control, Trust Issues, Security Threats, Vulnerabilities, Multitenancy, Virtualization