Blockchain-Based Group Covert Communication for IoT Network

The rapid development of the Internet of Things has increased the importance of IoT data privacy. Traditional encryption and access control mechanisms are insufficient for ensuring privacy. Blockchain-based covert communication offers enhanced concealment, anonymity, and immutability for secure information exchange over open networks. However, existing blockchain-based schemes face limitations in point-to-point communication and low screening efficiency and concealment, as well as challenges when extended to group scenarios, such as the existence of leakers. To address these issues, we propose a Blockchain-based Group Covert Communication (BGCC) scheme. BGCC leverages broadcast encryption to revoke leakers and introduces an efficient covert filtering mechanism based on the decisional ℓ-BDHE assumption. We prove its concealment through security reduction, statistical tests, and machine learning test. Experimental results demonstrate that BGCC outperforms existing schemes.