Yugala: Blockchain Based Encrypted Cloud Storage for IoT Data

Cloud storage enables users to upload, store and download their data. However, with the rapid growth of the Internet of Things (IoT) and edge devices, such as camera, the cloud not only manages the user generate data but also devices generated data. This increment in the volume of outsourced data has raised two important issues in big data management for cloud storage servers, namely, optimal data storage and data security. In order to solve the former issue, cloud storage employs a deduplication technique to avoids storing duplicate data; and uses encryption to solve the later issue. However, both these issues are orthogonal in nature. Thanks to convergent encryption that addresses both the issues simultaneously. Nevertheless, the existing approaches relies on proxy servers and put all the trust on third party, which is vulnerable to single point failure. In this paper, we propose a novel lightweight decentralized encrypted cloud storage architecture called, Yugula, which maintains file confidentiality, removes the centralized data deduplication and increases file integrity by using blockchain. In particular, we discuss two approaches for file confidentiality with data deduplication: one uses double hashing and the other symmetric encryption. In order to show the efficiency and usability, we implemented the proposed architecture and showed its results in terms of high transaction throughput requirement for IoT data management in cloud storage.