Security Research On De-duplication With Encrypted Data For Cloud Storage

Recent years with the rapid development of network, data increases day by day. Cloud service is born in this environment and develops fast. Cloud storage extends from cloud computation, and now it has already developed into an independent discipline. But the problems of the public cloud storage are coming out. Most of the existing cloud storage using plaintext even for data encryption its key is managed by cloud side, and their data would be convenient to de-dupliaction. Therefore, data security and users' privacy has already become much more concerned topic.Data encryption is mainly used to ensure data security when transfer and store. Data de-duplication is majority for cloud storage space savings to reduce store costs, and is to maximize allocation of resources, promote its utilization. This paper takes advantages of symmetric encryption, asymmetric encryption and convergence of encryption in order to ensure data transfer and storage security, and puts forward a new concept partially trusted proxy group on behalf of the real data holder to validate data ownership, and data index and fingerprint are separated, in order to reduce credibility of cloud, fingerprint separated aims to reducing risk of single agent leaks. In POW model communication between validation group and de-duplicated users takes advantage of agent encrypt and convergence of encryption, in order to avoid middle attack. At last paper realizes cloud de-duplication on file level between user and user based on POW model.The improved scheme not only improves the data security and protects users' privacy, but also ensures data de-duplication availability for cloud. Therefore, cross client de-duplication based on ciphertext is still has a long term research significance.