Panda: Public Auditing for Shared Data with Efficient User Revocation in the Cloud
Panda: Public Auditing for Shared Data with Efficient User Revocation in the Cloud
复制标题
Panda：在云中通过高效的用户撤销对共享数据进行公共审计
DOI：
10.1109/tsc.2013.2295611
复制
发表时间：
2015-01-01
影响因子：
8.1
通讯作者：
Li, Hui
中科院分区：
文献类型：
--
作者：
Wang, Boyang;Li, Baochun;Li, Hui
有了云中的数据存储和共享服务，用户可以轻松地修改和共享数据作为一个组。为了确保共享数据的完整性可以被公开验证，组中的用户需要对共享数据中的所有块进行签名计算。由于不同用户执行的数据修改，共享数据中的不同块通常由不同用户签名。出于安全原因，一旦用户从组中被吊销，先前由该被吊销用户签名的块必须由现有用户重新签名。这种简单的方法允许现有用户下载相应部分的共享数据，并在用户撤销期间对其进行重新签名，由于云中共享数据的大小，这种方法效率低下。在本文中，我们提出了一种新的共享数据完整性公共审计机制，该机制考虑了有效的用户撤销。通过使用代理重签名的思想，允许云在用户撤销时代表现有用户对块进行重新签名，从而使现有用户不需要自己下载和重新签名块。此外，公共验证者始终能够审计共享数据的完整性，而无需从云中检索整个数据，即使共享数据的某些部分已被云重新签名。此外，我们的机制能够通过同时验证多个审计任务来支持批量审计。实验结果表明，该机制能显著提高用户撤销的效率。
With data storage and sharing services in the cloud, users can easily modify and share data as a group. To ensure shared data integrity can be verified publicly, users in the group need to compute signatures on all the blocks in shared data. Different blocks in shared data are generally signed by different users due to data modifications performed by different users. For security reasons, once a user is revoked from the group, the blocks which were previously signed by this revoked user must be re-signed by an existing user. The straightforward method, which allows an existing user to download the corresponding part of shared data and re-sign it during user revocation, is inefficient due to the large size of shared data in the cloud. In this paper, we propose a novel public auditing mechanism for the integrity of shared data with efficient user revocation in mind. By utilizing the idea of proxy re-signatures, we allow the cloud to re-sign blocks on behalf of existing users during user revocation, so that existing users do not need to download and re-sign blocks by themselves. In addition, a public verifier is always able to audit the integrity of shared data without retrieving the entire data from the cloud, even if some part of shared data has been re-signed by the cloud. Moreover, our mechanism is able to support batch auditing by verifying multiple auditing tasks simultaneously. Experimental results show that our mechanism can significantly improve the efficiency of user revocation.