A cloud storage system which incorporates the deletion and deduplication functionalities will have both security and efficiency advantages over exiting solutions which provide only one of them. However, the security models of secure data deletion and data deduplication functionalities are not compatible with each other, which will cause security and efficiency vulnerability under coercive adversaries. To solve these security and efficiency challenges, we define and construct a scheme, whose security relies on the proper erasure of keys in the wrapped key tree and periodical update of the deduplication encryption keys. Moreover, we enhance the efficiency of the proposed scheme by introducing incremental data update, where only the changed part is encrypted/decrypted and uploaded/downloaded in data updating. Further security analysis shows that the proposed scheme is secure against coercive attack. Finally, the practical implementation shows that our scheme is performance efficient in computation, storage and communication for both the cloud storage server and users.
A Secure Erasure Code-Based Cloud Storage System with Secure Data Forwarding
