Cloud computing has been seen as the next generation architecture of IT enterprise. The cloud paradigm advantages and its potential for decreasing costs and reducing the time for a service that favours towards security issues. Cloud Computing is an aggregation of IT services that offered to the customer based on leasing. Though a large number of security issues are addressed, still some are not addressed and several algorithms are proposed for security issues. This paper presents a perspective

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... f cloud computing technologies, essential characteristics, classifications, delivery models and various encryption mechanisms. A comparative study made on several encryption techniques are used for maintaining the confidentiality in the cloud. Finally, the major data security issues present in cloud computing are discussed. Based on the customer service and their usage, the cloud can be classified as public, private, community, and hybrid.