Abstract: Cloud computing provides a service based on internet for several shared resources and system software across various environment. The major advantages of storing applications and documents in public cloud are lower cost through use of shared computing resources and no upfront infrastructure costs. Security and privacy represent major concerns in the adoption of cloud technologies for data storage as the network are open to many other users. Thus encryption with a fine grained access control is inevitable to enforce security in clouds. Several techniques implementing attribute based encryption for fine grained access control have been proposed. Under such approaches, the encryption technique creates a little bit overhead to the data owner and also the key management overhead is a little bit high in terms of computational complexity. Our proposed approach addresses these requirements and reduces the lack in encryption technique, the overhead of the key management by using efficient algorithms and protocols in the cloud computing two layer encryption environment.

Keywords: Cloud computing, attribute-based encryption, decentralised dynamic broadcast encryption, access control, group key management, fine grained access