A Flexible Dynamic Data Sharing Scheme with Revocation and Traceability in Cloud Computing

With the application of 5G and information technology, the secure sharing of data has become one of the core issues in cloud computing. Many methods have been proposed to solve these problems. Among them, the methods issued from attribute-based encryption (ABE) have highlighted the advantages such as the flexible access mechanism. But the traditional access policy structure is easy to expose user privacy. A circuit-based access policy addresses these shortcomings. However, existing circuit access structure are complex. And the revocation and traceability are also not considered in them. Based on the above, a sharing scheme over ABE for general circuits is proposed. It is the first practical circuit structure scheme supporting both revocation and traceability. In the proposed scheme, most part of the computation is outsourced to the cloud, which makes the computing overhead of users simple and constant. Finally, it is proven that the scheme can resist the collusion attack and achieve forward and backward security.