Abstract: The deduplication of data is the technique used for avoiding the redundancy of data by placing only one physical copy in the cloud storage. The data uploaded by the users are compared to the history of data in the cloud storage and it is ideal for highly redundant operations like backup which requires repeatedly copying and storing the same data set a number of times for purpose of recovery. To protect the data and to ensure confidentiality while supporting deduplication, convergent encryption technique has been designed to encrypt the data and this encrypted data will be stored in the cloud. The concept of convergent key is used to ensure the confidentiality and authenticity of the secure deduplication system. The concept of master key is used which enables us to protect the convergent key sent by the third party to the users and this ensures the authenticity of the convergent key Dekey is the derived key, which is the second approach, in which users do not need to manage any keys on their own but instead securely distribute the convergent key shares across the hash table.

Keywords: Confidentiality, Authenticity, Convergent encryption, Key management, Deduplication.