LightPoW: A trust based time-constrained PoW for blockchain in internet of things

Abstract

Blockchain has been widely used in the Internet of Things (IoT) to address security problems such as DDoS and Sybil. However, how to design a lightweight Proof-of-Work (PoW) for the IoT without compromising security is still a problem. To solve this problem, we propose a lightweight PoW for blockchain in IoT. Firstly, we present Heterogeneity Considered Trust Mechanism (HCTM) for IoT nodes, which evaluates the trust value according to capacity and quality, and makes the trust evaluation more reasonable. Then, we present Trust based Time-Constrained PoW (TBTC-PoW). We allocate reasonable time windows to the consensus nodes according to the computing resources, trust values and mining difficulty, which reduces the energy consumption and improves the security of PoW. Theoretical analysis and experimental results show that our method has a lower energy consumption and higher security.