Cloud storage enables data users to store and access their data anytime, from any location, using any device, under a pay-per-use policy. However, cloud storage raises various security concerns such as integrity and availability of data. To address these problems simultaneously, recently, several multi-replica integrity auditing schemes have been proposed in the literature. However, most of the existing schemes are designed based on either the public key infrastructure (PKI) or identity-based cryptography (IBC), which suffers from a big burden of certificate management or key escrow problems. In this paper, we propose a Certficateless Multi-Replica Dynamic Public Auditing Scheme for Shared data in cloud storage to solve these problems. Our scheme supports shared data dynamics through a novel data structure, namely, the replica version table. Further, our scheme also supports secure user revocation from the group. Through the security analysis, we prove that our scheme is provably secure against type I/II/III adversaries under the hardness assumption of the standard CDH and DL problems in the random oracle model (ROM). The performance and experimental evaluation show that our scheme is efficient and practical.

云存储使数据用户可以根据使用情况付费的策略，随时随地使用任何设备存储和访问其数据。但是，云存储引发了各种安全问题，例如数据的完整性和可用性。为了同时解决这些问题，最近，文献中提出了几种多副本完整性审计方案。但是，大多数现有方案都是基于公钥基础结构（PKI）或基于身份的密码学（IBC）来设计的，它们遭受着证书管理或密钥托管问题的沉重负担。本文针对云存储中的共享数据提出了一种无证书的多副本动态公共审计方案，以解决这些问题。我们的方案通过新颖的数据结构（即副本版本表）支持共享数据动态。此外，我们的方案还支持从组中安全地撤消用户。通过安全性分析，我们证明了在随机预言机模型（ROM）中采用标准CDH和DL问题的严格假设下，我们的方案针对I / II / III型对手具有可证明的安全性。性能和实验评估表明，该方案是有效和实用的。