Multiauthority Attribute-Based Encryption for Assuring Data Deletion

Abstract

In order to alleviate key escrow issue, the notion of multiauthority attribute-based encryption (MA-ABE) was presented, which was widely applied in cloud storage environment. In data sharing environment, secure data deletion is very crucial and challenging issue. Hence, in this article, we concentrate on verification of data deletion operation, i.e., assuring data deletion. To solve this problem, we put forward a system model, formal definition and security model of MA-ABE for assuring data deletion. Furthermore, we design a MA-ABE scheme for assuring data deletion, which is more practicable than the single authority ABE scheme. The designed scheme not only overcomes key escrow issue, but also resists collusion attack between malicious user and unauthorized user. In addition, our scheme utilizes merkle hash tree to obtain verifiable data deletion. Based on decisional bilinear Diffie-Hellman (DBDH) assumption, the scheme is proven to be secure under the selective-policy model. The experimental result indicates that the designed scheme is efficient for practical application.