R&D: Blockchain-Based Searchable Encryption Scheme for Multiple Cloud Storage

Springer Nature Switzerland has published, in CSS 2019: Cyberspace Safety and Security, International Symposium on Cyberspace Safety and Security proceedings, an article written by Chao Zhang, College of Computer National University of Defense Technology, Changsha, China, Shaojing Fu, College of Computer National University of Defense Technology, Changsha, China, and State Key Laboratory of Cryptology, Beijing, China, and Weijun Ao, College of Computer National, University of Defense Technology, Changsha, China.

Abstract: “Searchable encryption is a necessary and important service for cloud storage since it can realize the function of information retrieval on encrypted cloud data while protecting privacy. However, the typical searchable encryption models consisting of only a single cloud service provider can not prevent malicious behavior. In this paper, a new searchable encryption scheme in multi-cloud was proposed based on blockchain. We first define a system model based blockchain in multiple clouds and combine multiple cloud service providers together to store data together through a consortium chain. And then we store the encrypted document and document index in the IPFS, at the same time the hash value of the documents and the IPFS address of the document are stored in blockchains. Our scheme can provide a sorting retrieval scheme based on multi-keywords over the outsourced encrypted data and a validation scheme to detect file integrity. The theoretical analysis and experiments on real-world data show the security and high performance of our scheme.“