Comment on “Privacy-preserving public auditing for non-manager group shared data”

Abstract

Using cloud storage, users can remotely store their data without the burden on complicated local storage management and maintenance. However, users will no longer physically possess the storage of their data after they upload the data to the cloud. It is very natural for users to suspect whether their data stored in the cloud is intact. To help users efficiently check the integrity of the outsourced data, many public auditing schemes have been proposed. Recently, Huang et al. have proposed a privacy-preserving public auditing scheme for non-manager group shared data. In this paper, we find a security flaw in their auditing scheme. Even if the cloud has deleted or polluted the whole outsourced data, it still can pass the verification of the verifier. And then, we overcome this shortcoming by improving their scheme, which prevents the cloud forging a valid proof to pass the integrity auditing. Last, we perform the concrete implementation of our improved scheme and Huang et al. ’s scheme.