Shared Dynamic Data Audit Supporting Anonymous User Revocation in Cloud Storage

Collusion between revoked users and cloud service providers can pose a threat to the security of cloud storage data. If the original legitimate users cannot be revoked securely, it will lead to the leakage of shared data, thus affecting the security of cloud storage. In this paper, we combine vector commitment and anonymous revocation of group signature to propose an integrity audit scheme for cloud storage data that can support data modification. The anonymity of the group signature ensures that users' privacy information will not be snooped by the server. The proposed scheme supports the dynamic operation of stored data by legitimate group users besides data owners. When the user behaves improperly, the membership can be revoked by the group manager. After the user-modified data is stored in the cloud, whether the cloud server correctly stores the data can be audited by a trusted third party. Security analysis and experimental results demonstrate that our scheme is secure and efficient.