Abstract: Data de-duplication is one of important data compression techniques for eliminating duplicate copies of repeating data, and has been widely used in cloud storage to reduce the amount of storage space and save bandwidth. To protect the confidentiality of sensitive data while supporting de-duplication, the convergent encryption technique can be used to encrypt the data before outsourcing. To better protect data security, this paper is attempting to make a survey for data security methods that accounts for both security and storage efficiency. Different from traditional de-duplication systems, the differential privileges of users are considered in authorized duplicate check besides the data itself in the proposed scheme. The methods can be included in the hybrid cloud approach for effective de-duplication.

Keywords: de-duplication, authorized duplicate check, confidentiality, hybrid cloud.