DeyPoS: Deduplicatable Dynamic Proof of Storage for Multi-User Environments

ABSTRACT:

Dynamic Proof of Storage (PoS) is a useful cryptographic primitive that enables a user to check the integrity of outsourced files and to efficiently update the files in a cloud server. Although researchers have proposed many dynamic PoS schemes in single user environments, the problem in multi-user environments has not been investigated sufficiently. A practical multi-user cloud storage system needs the secure client-side cross-user deduplication technique, which allows a user to skip the uploading process and obtain the ownership of the files immediately, when other owners of the same files have uploaded them to the cloud server. To the best of our knowledge, none of the existing dynamic PoSs can support this technique. In this paper, we introduce the concept of deduplicatable dynamic proof of storage and propose an efficient construction called DeyPoS, to achieve dynamic PoS and secure cross-user deduplication, simultaneously. Considering the challenges of structure diversity and private tag generation, we exploit a novel tool called Homomorphic Authenticated Tree (HAT). We prove the security of our construction, and the theoretical analysis and experimental results show that our construction is efficient in practice.

EXISTING SYSTEM:

• In most of the existing dynamic PoSs, a tag used for integrity verification is generated by the secret key of the uploader. Thus, other owners who have the ownership of the file but have not uploaded it due to the cross-user deduplication on the client-side, cannot generate a new tag when they update the file. In this situation, the dynamic PoSs would fail.
• Halevi et al. introduced the concept of proof of ownership which is a solution of cross-user deduplication on the client-side. It requires that the user can generate the Merkle tree without the help from the cloud server, which is a big challenge in dynamic PoS.
• Pietro and Sorniotti proposed another proof of ownership scheme which improves the efficiency.
• Xu et al.proposed a client-side deduplication scheme for encrypted data, but the scheme employs a deterministic proof algorithm which indicates that every file has a deterministic short proof. Thus, anyone who obtains this proof can pass the verification without possessing the file locally.

DISADVANTAGES OF EXISTING SYSTEM:

• Existing dynamic PoSs cannot be extended to the multi-user environment.
• All existing techniques for cross-user deduplication on the client-side were designed for static files. Once the files are updated, the cloud server has to regenerate the complete authenticated structures for these files, which causes heavy computation cost on the server-side.
• Due to the problem of structure diversity and private tag generation, existing system cannot be extended to dynamic PoS.
• Unfortunately, these schemes cannot support deduplication due to structure diversity and private tag generation.

PROPOSED SYSTEM:

• To the best of our knowledge, this is the first work to introduce a primitive called deduplicatable dynamic Proof of Storage (deduplicatable dynamic PoS), which solves the structure diversity and private tag generation challenges.
• In contrast to the existing authenticated structures, such as skip list and Merkle tree, we design a novel authenticated structure called Homomorphic Authenticated Tree (HAT), to reduce the communication cost in both the proof of storage phase and the deduplication phase with similar computation cost.
• Note that HAT can support integrity verification, dynamic operations, and cross-user deduplication with good consistency.
• We propose and implement the first efficient construction of deduplicatable dynamic PoS called Dey-PoS, which supports unlimited number of verification and update operations. The security of this construction is proved in the random oracle model, and the performance is analyzed theoretically and experimentally.

ADVANTAGES OF PROPOSED SYSTEM:

• It is an efficient authenticated structure.
• It is the first practical deduplicatable dynamic PoS scheme called DeyPoS and proved its security in the random oracle model.
• The theoretical and experimental results show that our DeyPoS implementation is efficient,
• Performs better especially when the file size and the number of the challenged blocks are large.

SYSTEM ARCHITECTURE:

SYSTEM REQUIREMENTS:

HARDWARE REQUIREMENTS:

• System                           :         Pentium Dual Core.

• Hard Disk                      :         120 GB.

• Monitor                         :         15’’ LED

• Input Devices                 :         Keyboard, Mouse

• Ram                               :         1GB.

SOFTWARE REQUIREMENTS: 

• Operating system                    :         Windows 7.
• Coding Language           :         JAVA/J2EE
• Tool                               :         Netbeans 7.2.1
• Database                        :         MYSQL

REFERENCE:

Kun He, Jing Chen, Ruiying Du, Qianhong Wu, Guoliang Xue, and Xiang Zhang, “DeyPoS: Deduplicatable Dynamic Proof of Storage for Multi-User Environments”, IEEE Transactions on Computers, 2016.