Cloud storage has become a commonplace of storing and sharing data across multiple users. It is a challenge to preserve confidentiality and maintain identity privacy while sharing data within multiple dynamic groups, due to frequent change in the membership. Also, maintaining data integrity is an issue as data is stored and audited by untrusted Cloud Service Provider (CSP). In this paper, they propose, Third Party Auditor (TPA) auditing scheme to maintain data integrity and enabling TPA to perform audits for multiple users efficiently and simultaneously. By exploiting group signature scheme any member can anonymously share data within the group.