ABSTRACT: Protecting the data andcontrolling its access is a challenging problem for cloud storage which is openfor public. Ciphertext Policy Attribute-Based Encryption (CP-ABE) has beenembraced as a promising ability to give flexible, fine-grained and secureinformation access control for public cloud storage with genuine yetinquisitive cloud servers. However various works have been proposed utilizingCP-ABE technique, in which the single attribute authority must execute thetedious client authenticity confirmation and secret key distribution and thusit brings about a single point execution bottleneck when a CP-ABE technique isembraced in a large-scale cloud storage framework. Clients may be stuck in thewaiting line for a long stretch to get their secret keys, which results inlow-efficiency of the framework. Even though the multiple authority accesscontrol plans are proposed, these plans still not able to conquer thedisadvantages of the single-point bottleneck problem and low efficiency;because of the way that each of the authority still autonomously deals with adisjoint attribute set. In this work, it has been proposed a novel system toexpel the issue of single point execution bottleneck and give a more effectiveaccess control scheme with an auditing system. This framework utilizes multipleattribute authorities to share the heap of client authenticity check. In the interim,in this plan, a CA (Central Authority) is acquainted with producing secret keysfor authenticity checked clients and each of the AAs (Attribute Authorities) inour scheme manages the whole attribute set individually. This system makesperformance improvement in key generation and also guarantees securityrequirement. To improve the system, it has been proposed to choose one amongAAs to act as CA instead of separate CA and have an observer to trace if CA isworking properly or not. If observer finds any discrepancy it creates a reportand new CA chosen from AAs. This makes the system more secure and efficient andemanates forensic analysis.
KEYWORDS- Public Cloud storage, Access control, Auditing, CP-ABE, MultipleAuthority.