Privacy-Preserving Cloud Auditing for Multiple Users Scheme With Authorization and Traceability

Abstract

With the widespread application of cloud storage, users could obtain many conveniences such as low-price data remote storage and flexible data sharing. Considering cloud service provider (CSP) is not full-trusted, lots of cloud auditing schemes are proposed to ensure the shared data security and integrity. However, existing cloud auditing schemes have some security risks, such as user identity disclosure, denial of service attack and single-manager abuse of power. To solve the above issues, we use certificateless signature technology to construct a privacy-preserving cloud auditing scheme for multiple users with authorization and traceability in this paper. Unlike the traditional schemes, our scheme realizes user identity anonymity without group signature and ring signature techniques, which guarantees the tag is compact. Meanwhile, our scheme supports that at least d managers could trace the identity of malicious user collaboratively, which avoids the abuse of single-manager power and provides non-frameability. Furthermore, we introduce an identity authentication process between the third-party auditor (TPA) and the CSP to prevent the denial of service attack. That is, our scheme could solve the problem that anyone can challenge the CSP for the proofs, which averts network congestion and waste of cloud resources. In terms of function, the proposed scheme also supports efficient user revocation from a group. Certificateless cryptography ensures that our scheme does not involve certificate management burden and the key escrow problem. The security analysis shows that our scheme is provably secure against two types of adversaries in the environment of certificateless cryptography. The performance analysis demonstrates that our scheme is efficient.

Certificateless Reliable and Privacy-Preserving Auditing of Group Shared Data for FOG-CPSs

“…is can happen only when the Proof-Ver algorithm resulted in success for each of the instance t ∈ T, since we assume that the data auditor executed the Proof-Ver algorithm honestly for each of these instances. Hence, each of the instance t ∈ T must satisfy equation (20), i.e.,…”

“…Since both proofs P 1u and P 2u are valid proofs, they must satisfy auditor verification equation (20):…”

“…In CLPKC, like IBC, the authenticity of the public key of an user is implicit; however, the full private key of an user is known only to that user. Recently, a number of CLPKC-based shared data auditing protocols have been proposed in the literature [16][17][18][19][20][21][22][23][24]39] for traditional cloud storage systems. However, these protocols cannot be directly adopted for a FOG-CPS because of its discriminating characteristics as discussed below.…”

“…e CLPKC-based group shared data auditing protocols proposed in [16][17][18][19][20][21][22] trust the data auditor on the data confidentiality and hence do not provide any data privacy mechanisms against the auditor. In these protocols, the auditor can extract the data blocks from the information received from the cloud as part of the data auditing process.…”

Privacy Preserving Dynamic Provable Data Possession with Batch Update for Secure Cloud Storage

“…Certificateless authentication [29], [30] is one of the cryptographic techniques for authentication. Some authors proposed privacy-preserving integrity verification scheme [31], [32] using certificate-less ring signature which greatly reduces the computation cost during auditing. Li et al [19] proposed integrity checking of group shared data using certificateless signature.…”