云存储中基于虚拟用户的数据完整性验证

Virtual-user-based Public Auditing Integrity in Cloud Storage

针对验证数据完整性过程中被撤销用户与云服务器存在共谋的问题,提出基于虚拟用户的数据完整性校验方案。在管理群组用户的过程中,管理员让云服务器作为代理,通过重签名方法将被撤销用户的签名转换为虚拟用户签名,以防止攻击者获取群组用户身份隐私信息。另一方面,管理员在本地存储所有用户的身份隐私信息,用户在访问共享数据之前需要通过管理员的验证,这样既能保证校验者可以正确验证共享数据的完整性,又能保护群组用户的隐私和共享数据的安全。分析证明结果表明,所提方案在用户撤销时不仅能够验证共享数据的完整性,还能降低攻击者精确获取用户身份隐私信息和共享数据内容的概率。

A public auditing integrity mechanism based on the virtual user was proposed,addressing collusion issue be- tween the revoked user and cloud. After the user is revoked from the group, the manager lets the proxy resign the blocks with the virtual user＇ s signature, which utilizes proxy re-signature to protect user＇ s privacy. In addition, the manager verifies the user who want to access the shared data via a local list consisting of all users＇ identity, with objec- tive of auditing data integrity and protecting user＇ s privacy. Theoretical analysis shows that our framework achieves significant performance improvement in security and privacy, and it can decrease the probability of an adversary to get the users＇ identity privacy and the data in the cloud.