Cloud computing allows users to store their datas in cloud and those datas can be shared by different users.So the integrity of cloud data is subject to doubt.Current approach used privacy-preserving mechanism that supports public auditing on shared data stored in the cloud. They exploited ring signatures to compute verification metadata needed to audit the correctness of shared data. With this, the identity of the signer in shared data is also kept private from public verifiers. Since the traditional approach is based on ring signatures, where the identity of the signer is unconditionally protected, it does not support traceability.But designing an efficient public auditing mechanism with the capabilities of preserving identity privacy and supporting traceability is still open.So here, we propose a traceability mechanism which means the ability for the group manager (i.e., the original user) to reveal the identity of the signer based on verification metadata in some special situations and data freshness(cloud possess the latest version of data) is also achieved.
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Traceability, Privacy Preserving, Public Auditing, Shared data.(