Attribute-based public integrity auditing for shared data with efficient user revocation in cloud storage

Abstract

With the exponential growth of cloud storage services, users can easily form a group and share the data with one another in the group. Since the cloud is untrusted and users deprived of direct control over data, it is essential to guarantee the integrity of shared data in the cloud. Several public auditing schemes have been proposed based on public key infrastructure or identity-based cryptography to check the integrity of outsourced data. However, they suffer from complex key management. Besides, how to achieve user privacy and efficient revocation is also a challenge in shared data auditing. To address these issues, in this paper, we propose attribute-based public auditing for shared data in the cloud storage. In our scheme, users sign data blocks over a set of attributes without disclosing any identity information, and a unique public key is used to verify the integrity instead of the individual public key of each user. Further, our scheme achieves user revocation through proxy re-signatures. Security analysis proves that our scheme is provably secure. The performance analysis demonstrates the practicality of the scheme.