Secure and Efficient Data Sharing for IoT Based on Blockchain and Reputation Mechanism

The escalating adoption of Internet of Things (IoT) technologies produces vast amounts of real-time data, which can be shared and analyzed to enhance productivity and product quality across various industries. Unfortunately, the current IoT systems rely heavily on cloud servers for centralized data management. These systems not only suffer from the single point of failure problems but also have data security issues. The malicious users may compromise user privacy or inject corrupted data during the data sharing process. In this article, we propose a secure and efficient data sharing scheme for IoT. First, the scheme integrates blockchain with the distributed database, utilizing smart contracts to ensure secure data storage, querying, and sharing in IoT. Second, we incorporate a reputation mechanism into the data sharing process. This allows IoT users to receive reputation feedback from their partners based on their behaviours, which is dynamically updated as a reputation score on the blockchain by smart contracts. Therefore, honest users get more opportunities to share data, while malicious users are held accountable and revoked from the IoT system. We also harness advanced cryptographic techniques to ensure the submission of reputation feedback does not disclose the user's private information, preventing vindictive actions from malicious users. Finally, we demonstrate the security and effectiveness of the proposed scheme by conducting the security analysis and the detailed experiments.