An Energy-Efficient Wireless Blockchain Sharding Scheme for PBFT Consensus

Blockchain technology has gained considerable attention in wireless network scenarios due to its security features. However, the complex workflow of blockchain consensus negotiation often results in high energy consumption. This may cause nodes to run out of energy quickly and go offline, especially in wireless networks with limited node battery capacity. To improve this issue, we propose a sharding scheme named Green Sharding (GS), which minimizes the energy consumption for Practical Byzantine Fault Tolerance (PBFT) consensus. The GS assigns nodes in a wireless blockchain network to specific shards based on their geographical location, thereby avoiding their participation in a global consensus. Meanwhile, we also propose an estimation method of energy consumption after sharding, to simplify the energy consumption computing of sharded wireless blockchain networks. Furthermore, we provide an optimal algorithm for committee node (CN) selection, which can further decline the energy consumption of committee consensus on the GS basis. At last, we analyze and simulate the GS performance for two 6G communication scenarios: the terahertz (THz) and the millimeter wave (mmWave) signals. The simulation results prove the effectiveness of the GS, which reduces energy consumption by 99.76%, and the minimum error of our estimation method is only 0.11%.

I. Introduction

The integration of cryptography and consensus has resulted in the emergence of blockchain, a ground-breaking distributed system with a decentralized architecture and formidable tamper-proof capability. As such, it holds tremendous potential to revolutionize information sharing and transform society in the future. Additionally, the application of blockchain technology in the realm of information and communication holds promise for enhancing the security of wireless networks [1], [2], [3]. Moreover, the use of blockchain has increasingly pervaded other network fields, such as the Internet of Things (IoT) [4], the Internet of Drones (IoD) [5], and the Web 3.0 [6].