A data assured deletion scheme in cloud storage

In order to provide a practicable solution to data confidentiality in cloud storage service, a data assured deletion scheme, which achieves the fine grained access control, hopping and sniffing attacks resistance, data dynamics and deduplication, is proposed. In our scheme, data blocks are encrypted by a two-level encryption approach, in which the control keys are generated from a key derivation tree, encrypted by an All-Or-Nothing algorithm and then distributed into DHT network after being partitioned by secret sharing. This guarantees that only authorized users can recover the control keys and then decrypt the outsourced data in an owner-specified data lifetime. Besides confidentiality, data dynamics and deduplication are also achieved separately by adjustment of key derivation tree and convergent encryption. The analysis and experimental results show that our scheme can satisfy its security goal and perform the assured deletion with low cost.