Towards Fully Anonymous Integrity Checking and Reliability Authentication for Cloud Data Sharing

Cloud storage services improve the efficiency and popularity of data sharing. These services allow groups of participants to jointly maintain the shared data. As important security properties of cloud data sharing, the integrity and the reliability of the shared data have been studied recently. However, the existing research cannot sufficiently solve the issue of participant identity anonymity in the scenario of data modification. In this paper, we propose a novel approach to achieve fully anonymous integrity checking and reliability authentication for cloud data sharing. We design a predicate for the shared data, and construct the Lagrange interpolation polynomials for all participants to compute the secret keys based on the designed predicate. When modifying the shared data, the participants compute the authenticators of the modified data using the secret key associated with the designed predicate instead of their identities. In this way, the integrity checking and reliability authentication of the shared data modified by different participants can be performed while the identities of the corresponding participants remain fully anonymous. In addition, the traceability and revocation of participant identity are considered. The performance analysis demonstrates the efficiency of the proposed approach, and the security analysis shows that the proposed approach satisfies the desired properties.