Empowered service delegation with attribute encryption for distributed cloud computing

Cloud computing has emerged as one of the most influential paradigms in the IT industry. In this, new computing technology requires users to entrust their valuable data to cloud providers, there have been increasing security and privacy concerns on outsourced data. Several schemes employing attribute-based encryption (ABE) have been proposed for access control of outsourced data in cloud computing. The most[1][2] of them suffer from inflexibility in implementing complex access control policies. In this paper, allowing cloud service providers (CSPs), which are not in the same trusted domains as enterprise users, to take care of confidential data, may raise potential security and privacy issues. To keep the sensitive user data confidential against untrusted CSPs, a Natural way is to apply cryptographic approaches, by disclosing Decryption keys only to authorized users. But also provide full delegation, and scalability, so as to best serve the needs of accessing data anytime and anywhere, delegating within enterprises, and achieving a dynamic set of users. [3][4]HASBE employs multiple value assignments for access expiration time to deal with user revocation more efficiently than existing schemes. It can be providefine-grained access control and full delegation. Finally, we propose a scalable revocation scheme by delegating to the CSP most of the computing tasks in revocation, to achieve a dynamic set of users efficiently.