On the Security of Three Public Auditing Schemes in Cloud Computing

Cloud computing provides a scalability environment for growing amounts of data and processes that work on various applications and services by means of on-demand self-services. It is necessary for cloud service provider to offer an efficient audit service to check the integrity and availability of the stored data in cloud. In this paper, we study three auditing schemes for stored data including the public auditing scheme with user revocation, the proxy provable data possession and the identity-based remote data possession checking. All three mechanisms claimed that their schemes satisfied the security property of correctness. It is regretful that this comment shows that an active adversary can arbitrary alter the cloud data to generate the valid auditing response which can pass the verification. Then, we discussed the origin of the security flaw and proposed methods to remedy the weakness. Our work can help cryptographers and engineers design and implement more secure and efficient auditing mechanism in the cloud.