Biblio

Rapid development of cloud storage services, users are allowed to upload heavy storage and computational cost to cloud to reduce the local resource and energy consumption. While people enjoy the desirable benefits from the cloud storage service, critical security concerns in data outsourcing have been raised seriously. In the cloud storage service, data owner loses the physical control of the data and these data are fully controlled by the cloud server. As such, the integrity of outsourced data is being put at risk in reality. Remote data integrity checking (RDIC) is an effective solution to checking the integrity of uploaded data. However, most RDIC schemes are rely on traditional public key infrastructure (PKI), which leads communication and storage overhead due to the certificate management. Identity-based RDIC scheme is not need the storage management, but it has a drawback of key escrow. To solve these problems, we propose a practical certificateless RDIC scheme. Moreover, many public auditing schemes authorize the third party auditor (TPA) to check the integrity of remote data and the TPA is not fully trusted. Thus, we take the data privacy into account. The proposed scheme not only can overcome the above deficiencies but also able to preserve the data privacy against the TPA. Our theoretical analyses prove that our mechanism is correct and secure, and our mechanism is able to audit the integrity of cloud data efficiently.

We seek to answer the following question: To what extent can we deduplicate replicated storage? To answer this question, we design ReDup, a secure storage system that provides users with strong integrity, reliability, and transparency guarantees about data that is outsourced at cloud storage providers. Users store multiple replicas of their data at different storage servers, and the data at each storage server is deduplicated across users. Remote data integrity mechanisms are used to check the integrity of replicas. We consider a strong adversarial model, in which collusions are allowed between storage servers and also between storage servers and dishonest users of the system. A cloud storage provider (CSP) could store less replicas than agreed upon by contract, unbeknownst to honest users. ReDup defends against such adversaries by making replica generation to be time consuming so that a dishonest CSP cannot generate replicas on the fly when challenged by the users. In addition, ReDup employs transparent deduplication, which means that users get a proof attesting the deduplication level used for their files at each replica server, and thus are able to benefit from the storage savings provided by deduplication. The proof is obtained by aggregating individual proofs from replica servers, and has a constant size regardless of the number of replica servers. Our solution scales better than state of the art and is provably secure under standard assumptions.

In the existing remote data integrity checking schemes, dynamic update operates on block level, which usually restricts the location of the data inserted in a file due to the fixed size of a data block. In this paper, we propose a remote data integrity checking scheme with fine-grained update for big data storage. The proposed scheme achieves basic operations of insertion, modification, deletion on line level at any location in a file by designing a mapping relationship between line level update and block level update. Scheme analysis shows that the proposed scheme supports public verification and privacy preservation. Meanwhile, it performs data integrity checking with low computation and communication cost.