Cloud computing is a collection of an Information and supplies them in rental bases. In cloud computing Data-Security is a major and a serious issue as data is located in different forms in different places. Data-Security is most important technique for the future development in industries, business and some for the governments. This is relevant to both the hardware and a software this will deals to protect the data in the cloud environment. Cloud has many advantages like flexibility; efficiency, scalability, and integration they provide the operations in advanced and run their applications. One current research activity no going is the Fault-detection it is the building block of reliability and multi-cloud solutions and implement these characteristics on a cloud testbed. This paper will study about the security issue and challenge to overcome from data hacking. Security is the main challenge in the cloud computing it is the heart of the cloud to keep the data secure. This paper discuss about the various security issues and the possible opportunities are stated and resolve the issues based on the techniques in the cloud computing. The major security opportunity discussed in this paper is encapsulation of data among others