Towards a blockchain-based decentralized reputation system for public fog nodes

The omnipresence of Internet of Things (IoT) devices nowadays has resulted in a large amount of data transferred regularly to the cloud. This continuous data transfer degrades the application performance in terms of latency, bandwidth consumption, connectivity, security, privacy, user experiences, and energy efficiency. Fog computing brings cloud services closer to the IoT devices. In public settings, variety of handheld and IoT devices need to connect to public fog nodes in order to access localized compute, storage, and networking capabilities. Therefore, the reputations of publicly available fog nodes become critical. Maintaining a reputation score is one of the popular techniques to ensure trust for fog nodes. This paper introduces a blockchain-based solution to establish trust in public fog nodes that provides services for IoT devices in a decentralized manner. Our proposed solution exploits blockchain smart contracts to compute the reputation in a decentralized manner by capturing and analyzing its past interactions with IoT devices. The solution also penalizes IoT devices that may collude to provide dishonest reputation scores.