Secured and reliable file sharing system with de-duplication using erasure correction code

An effective storage and management of file systems is very much essential now a days to avoid the wastage of storage space provided by the cloud providers. Data de-duplication technique has been used widely which allows only to store a single copy of a file and thus avoids duplication of file in the cloud storage servers. It helps to reduce the amount of storage space and save bandwidth of cloud service and thus in high cost savings for the cloud service subscribers. Today data that we need to store are in encrypted format to ensure the security. So data encryption by data owners with their own keys makes the de-duplication impossible for the cloud service subscriber as the data encryption with a key converts data into an unidentifiable format called cipher text thus encrypting, even the same data, with different keys may result in different cipher texts. But de-duplication and encryption need to work in hand to hand to ensure secure, authorized and optimized storage. In this paper, we propose a scheme for file-level de-duplication on encrypted files like text, images and even on video files stored in cloud based on the user's privilege set and file privilege set. This paper proposed a de-duplication system which distributes the files across different servers. The system uses an Erasure Correcting Code technique to re-construct the files even if the parts of the files are lost by attacking any server. Thus the proposed system can ensure both the security and reliability of encrypted files.