Secure data deletion in cloud storage: a survey

With the rapid development of cloud computing, individual people, firms, industries and governments are moving their data to clouds to meet the data explosion challenge. Secure data deletion is becoming a hot issue in cloud storage research. Different from traditional data deletion, the securely deleted data should be non-recoverable. In this paper, we present a survey of current secure data deletion technologies and make comparisons of them for both private cloud storage and public cloud storage. For private cloud storage, we introduce two main deletion methods: physical destruction and disk replication. For public cloud storage, we analyse the existing deletion methods such as balanced-tree-based, trusted-third-parties-based, policy-based secure data deletion methods and so on, in accordance with the two aspects of verifiable secure data deletion and verifiable non-recoverability of data. Finally, we analyse the deficiencies among current researches and propose some future directions for improvement in secure data deletion.