LAUSR

With the rapid development of cloud storage technology, cloud data assured deletion has received extensive attention. While ensuring the deletion of cloud data, users have also placed increasing demands on cloud data assured deletion, such as improving the execution efficiency of various stages of a cloud data assured deletion system and performing fine-grained access and deletion operations. In this paper, we propose an efficient scheme of cloud data assured deletion. The scheme replaces complicated bilinear pairing with simple scalar multiplication on elliptic curves to realize ciphertext policy attribute-based encryption of cloud data, while solving the security problem of shared data. In addition, the efficiency of encryption and decryption is improved, and fine-grained access of ciphertext is realized. The scheme designs an attribute key management system that employs a dual-server to solve system flaws caused by single point failure. The scheme is proven to be secure, based on the decisional Diffie-Hellman assumption in the standard model; therefore, it has stronger security. The theoretical analysis and experimental results show that the scheme guarantees security and significantly improves the efficiency of each stage of cloud data assured deletion.