ReLI: Real-Time Lightweight Byzantine Consensus in Low-Power IoT-Systems

IoT/WSN assisted smart-systems are making our living easier and more comfortable in various aspects. However, there is always a chance of malfunctioning in such massive decentralized systems in crucial moments because of one or more components of the system getting compromised. For instance, monitoring systems installed to watch the status of a bridge may unknowingly suppress the recent deterioration in the status because of some compromised sensing devices. Byzantine fault tolerance support is highly essential in combating the presence of such smart devices with malicious intentions. However, existing solutions for consensus or data aggregation in IoT/WSN systems either assume non-Byzantine node failures or use only simulation/theoretical models to address the existence of Byzantine nodes. Theoretically, a decentralized system can effectively tolerate Byzantine characteristics of up to a certain fraction of the nodes. However, to achieve even that, the nodes need to interact extensively and share data with each other which makes it challenging for such solutions to get practically realized and produce outcomes in real-time, especially in resource-constrained IoT systems. In this work, we adopt Synchronous-Transmission based mechanisms and propose a framework ReLI to efficiently achieve Byzantine consensus in low-power IoT systems. We show that ReLI can operate up to 80% faster and consume up to 78% lesser radio-on time compared to the traditional implementation of the strategy in a publicly available IoT/WSN testbed containing 45 nodes.