Search

For data owners of restricted cloud access with a delegated proxy, public auditing technology for cloud data integrity, plays critical roles in ensuring powerful productivity that flexible cloud services provide for their business. In order to address the scalability of data owners and storage clouds for secure public auditing, Yu et al. (2017) proposed an Identity-Based Public Auditing for Dynamic Outsourced Data with Proxy Processing (https://doi.org/10.3837/tiis.2017.10.019), which also overcomes complicated public key certificates management issue. In this article, we figure out that this scheme is vulnerable to data loss attack where clouds could pass integrity auditing without original data. Meanwhile, a threat of system security is demonstrated, i.e., any entities are able to recover proxy private keys and impersonate proxy to forge proxy tag, with two arbitrary data tag pairs of same data owner. To enable secure identity-based batch public auditing with proxy processing, we propose an improved scheme without these security flaws and prove its security under CDH hard problem in the random oracle model. With complexity analysis, our scheme shows better efficiency over identity-based proxy-oriented data uploading and remote data integrity checking in public cloud (ID-PUIC) in a single owner effort on a single cloud. Especially, we give the detailed analysis for how efficiently the attacks on Yu et al.'s scheme could be launched with an experiment, and demonstrate complete reduction on probability and time for proving security of our improved scheme. For potential application in big data storage, we first evaluate the error detection probability varying on number of auditing blocks, and then conduct detailed performance analysis by simulating our scheme and ID-PUIC scheme on the different number of data owners and storage clouds, with up to 106 data blocks. [ABSTRACT FROM AUTHOR]

Provable Data Possession (PDP), which enables cloud users to verify the data integrity without retrieving the entire file, is highly essential for cloud storage. Observing all the existing PDP schemes rely on the Public Key Infrastructure (PKI), Wang proposed an identity-based distributed provable data possession (ID-DPDP) scheme that can (1) eliminate the complex certificate management and (2) be applied to the multi-cloud scenario. The scheme is efficient, flexible and supports private verification, delegated verification and public verification. In this paper, we find that ID-DPDP is flawed since it fails to achieve soundness. We then fix the flaw by presenting a generic construction for identity-based PDP (ID-PDP) protocol, derived from secure digital signature schemes and traditional PDP protocols. We prove that the soundness of the generic ID-PDP construction depends on the security of the underlying PDP protocols and the signature schemes. An instance of the generic construction by utilizing a state-of-the-art PDP protocol due to Shacham and Waters and BLS short signature scheme is given. Moreover, a new ID-DPDP protocol is obtained by extending the basic ID-PDP to multiple clouds environment. The implementation shows that the proposed ID-PDP protocol is efficient. [ABSTRACT FROM AUTHOR]