Enhancing User Revocation Mechanisms for Shared Resources to Strengthen Data Security in Public Clouds

Users may quickly change and share data among themselves using cloud-based data storage and sharing services. Users in the group must calculate signatures on every block of mutually exchanged data to guarantee that its integrity can be independently validated by third parties. Due to data updates made by many users, separate blocks of shared data are typically signed by various end users. For security concerns, if a person left a group, the blocks they previously signed are no longer valid. A current user must sign again for this revoked user. The simple approach, which enables a current user to download the relevant portion of Resigning shared data after a user revokes their access is ineffective because of the amount of the shared information and data in the cloud. In this research paper, we provide a new method for public auditing that guarantees the state of information and data shared while improving the effectiveness of user revocation. Proxy re-signatures enable the cloud to relinquish data blocks on behalf of users who have had their access revoked, removing the requirement for these users to manually download and re-sign the blocks. Furthermore, a public verifier does not need to download the complete file in order to confirm data integrity, even in cases where the cloud has re-signed some of the shared data. Moreover, our approach makes batch auditing easier by allowing several auditing jobs to be validated at the same time. Experimental findings demonstrate that our technique can greatly increase the effectiveness of user revocation.