Blockchain-based cloud-edge clock calibration in IoT

The explosive growth of the IoT continues to change the way people live, followed by a plethora of IoT-based scenarios resources and applications, such as smart homes, smart grids, and smart transportation. In these scenarios, many IoT nodes form a complex the distributed system through the network, and these devices must have synchronized clocks to work together to complete distributed tasks. However, considering the limited processing ability of IoT devices, it is hard to calibrate their clocks directly through external trusted time sources. This paper proposes a scheme for IoT clock calibration under rational assumptions. The scheme introduces the IoT cloud server as an internal time source and provides calibration service for edge devices through communication links. In order to preserve and trace the service behavior to punish dishonest participants, the scheme combines blockchain technology for transaction verification and distributed storage. To ensure that the cloud server can always fulfill the protocol correctly, the scheme applies game theory to analyze the different benefits of the participants in the system based on different policies. Meanwhile, we design a new reward and punishment mechanism to motivate rational players to maximize their utility. In addition, the results of the scheme’s Bayesian game analysis show that there is a Nash equilibrium in the system.