用户身份可追踪的云共享数据完整性审计方案

Public Integrity Auditing for Shared Data in Cloud Supporting User Identity Tracking

云端共享数据完整性审计用于验证一个用户群组共享在云端的数据的完整性。与单用户的数据完整性审计相比,群组共享数据的完整性审计需要考虑用户撤销、身份隐私保护等问题。如果数据出现争议或其他情况,还需要对数据的来源进行追踪,目前已有的云共享数据完整性审计方案尚未能很好地处理这个问题。为了实现数据源的追踪,并保证高效的用户撤销和用户身份隐私的保护,文中提出基于群签名算法的云共享数据完整性审计方案。当需要追踪数据块签名者的身份时,群管理员可利用自己的私钥对数据块签名者的身份进行追踪,且他人无法得知该签名者的身份。该方案中的私钥更新机制能很好地支持用户撤销,极大缩减了用户撤销过程中的计算和通信开销。安全性分析和实验结果表明,该方案是安全、高效的。

Public integrity auditing for shared data in the cloud is used to verify the integrity of data shared by a group of users.Compared with the integrity auditing forsingle-user data,the integrity auditing for shared data of a group needs to consider more issues,such as efficient user revocation,identity privacy protection and so on.If there is a dispute or other situation in the data,the source of the data needs to be tracked,and existing integrity auditing schemes for shared cloud data have not yet handled this problem well.In order to track the source of data and ensure efficient user revocation and the protection of user’s identity privacy,an integrity auditing scheme based on group signature algorithm for shared cloud data is proposed.When it is necessary to track the identity of the signer of a data block,the group manager can track it by using his/her private key and others cannot know the identity of this signer.The private key update mechanism in this scheme can well support user revocation,and greatly reduce the computation and communication overhead during the user revocation process.Safety analysis and experimental results show that the scheme is safe and efficient.