This paper presents a survey on an attribute-based storage system with secure deduplication in a hybrid cloud setting with higher confidentiality and reliability. Deduplication is a technique which is widely employed to backup data and minimize network and storage overhead by detecting and eliminating redundancy among data. It eliminates duplicate copies of identical data in order to save storage space and network bandwidth. Private cloud is responsible for duplicate detection and a public cloud manages the storage. Instead of keeping multiple data copies with the same content, in this system eliminates redundant data by keeping only one physical copy and referring other redundant data to that copy. Each such copy can be defined based on user access policies, the user will upload the file with access policies and then file type question with answer. Then same file with different access policies to set the particular file to replace the reference. Applying deduplication to user data to save maintenance cost in HDFS storage system.

Keywords : Cloud Computing, Encryption Techniques, Classification, Data security, Authentication, Security in Cloud.