A Hierarchical Third Party Based Model for Security & Integrity in Multi Cloud Computing Environment - A Survey

It has been observed that the concept of cloud computing is increasing day by day in the world of IT industry in recent years. Data Owners are progressively counting on the cloud services for storing their data, backing up their data and use it in real time when ever needed. Since the data stored is online it requires data owners to entrust their valuable data to cloud service providers, so there ought to be increased security and privacy concerns on data. In this paper, various attribute based encryption schemes are explained such as key - policy attribute base encryption scheme , cipher - policy attribute based encryption scheme , cipher - policy attribute set based encryption scheme, Hierarchical identity based encryption scheme , Hierarchical attribute based encryption scheme and hierarchical attribute set based encryption scheme for providing security , integrity and fined grained access control of the outsourced data along with their strength and weaknesses. Also a new mechanism is presented, a hybrid model for providing security in cloud computing environment. This model combines the advantages of two most popular existing cloud security models.