A Secure Erasure CBCS System with Data Forwarding Technique

Abstract

A cloud storage system, provides long-term storage services over the Internet. A cloud storage system is considered as a large scale distributed storage system that consists of many independent storage servers.Storing data in a third party’s cloud system causes serious concern over data confidentiality. General schemes protect data confidentiality, but limits the functionality of the storage system because a few operations are supported over the encrypted data. Constructing a secure storage system that supports multiple functions is challenging when the storage system is distributed and has no central authority. We propose a proxy re encryption scheme and integrate it with a decentralized erasure code such that a secure distributed storage system is formulated. The distributed storage system not only supports secure and robust data storage and retrieval, but also lets a user forward his data in the storage servers to another user without retrieving the data back to the sender’s location . The basic technical contribution is that the proxy re-encryption scheme supports encoding operations over encrypted messages as well as forwarding operations over encoded and encrypted messages. Our method fully integrates encrypting, encoding, and forwarding. We analyze and suggest suitable parameters for the number of copies of a message dispatched to storage servers and the number of storage servers queried by a key server. These parameters allow more flexible adjustment between the number of storage servers and robustness, thus increasing the efficiency in storing the data with confidentiality and forwarding the data to another user by providing security