中文摘要：

在云存储网络环境中，数据的安全性、完整性和隐私性是用户最关心的问题之一。云存储服务中，用户将存储的数据和认证标识信息存储在云服务器中。为了保证存储数据的完整性．云存储服务提供者需要向用户或第三方审计者证明其正确地持有用户存储的数据。公共审计是指由用户以外的第三方代替用户完成审计工作。这对于计算资源比较有限的用户尤其重要。目前多数云存储审计方案没有考虑隐私性问题。本文提出了一种新的可聚合基于签名的广播加密（ASBB）方案，并在此基础上设计了新的满足隐私性的云存储公共审计方案。新方案在随机预言模型下是可证安全的，并且在计算开销方面更具有优势。

英文摘要：

When user stores their data in the cloud storage, they most concern about whether the data is complete, privacy and unchanged. To ensure the availability and integrity of users＂ stored data, cloud server must prove a verifier that it is actually storing all of a client＇s data unchanged. And, enabling public auditability for cloud storage is of critical importance to users with constrained computing resources, who can resort to a third party auditor to check the integrity of outsourced data. However, most of the existing auditing schemes do not consider data privacy problem. In this paper, after giving a new construction of a recently proposed primitive named aggregatable signature based broadcast encryption scheme, we present an efficient public auditing scheme with privacy property. The new scheme is secure in the random oracle model and has less computation cost than existing auditing scheme with privacy property.