ABSTRACT
The cloud computing is playing a major role in the evaluation of technical life of mankind with the successful execution of various cloud services such as software, application, platform, storage, and networking resources on a pay-per-use basis. Cloud data security is always the topmost priority of Cloud Service Providers. The cyber-attacks on cloud data prove that there is a need for continuous research for finding various updated ways to protect the cloud data from unauthorized users. Fully HEA allows computations on encrypted data without releasing the decryption key to the CSP. This review paper aims at focusing on various past proposed approaches or methodologies and their limitations, lagging issues that are related to cloud security. Based on these limitations, the future scope can be decided as what exactly can be the approach to protect the cloud data from unauthorized access to build a more secured CS.
