A Two-Layer-Consensus Based Blockchain Architecture for IoT

Due to its immutable and transparent nature, Blockchain (BC) provided a decentralized solution to overcome security and resource challenges of centralized Internet of Things (IoT). However, its integration with IoT is limited by scalability and expensive computation. To this end, we propose a two-layer-consensus based BC architecture optimized for IoT requirements. Low resource devices attached to the server and with users and other nodes form Base-Layer. There is a high-scalable and fully decentralized blockchain performing basic functions maintaining in Base-Layer, myriad blocks are mined and submitted every round, but only one block selected by Top-Layer can be recorded. Top-Layer with another high-security blockchain is formed by special nodes running a Non-byzantine fault tolerance algorithm to determine the accounting rights in random. Analysis and evaluation show that consensus has better fault tolerance and increases scalability.