SusChain: a sustainable sharding scheme for UAV blockchain networks

With the continuous development of information technology, drones have become the supporting technology for sustainable smart cities. Currently, the blockchain that guarantees the information security of the unmanned aerial vehicle (UAV) network has become the focus of academic attention. However, due to the small size of the drone, and its limited storage and battery capacity, it is difficult to support the sustainable work of the UAV blockchain network. Therefore, this paper proposes the concept of sustainable blockchain (SusChain) and empowers the UAV blockchain network to better apply it to sustainable smart cities. In particular, we have introduced and improved the Ultra-Low Storage Overhead-Practical Byzantine Fault Tolerance (ULS-PBFT) consensus in the UAV blockchain network, making it a sharding scheme with extremely low storage overhead and energy consumption. Meanwhile, we design a reptation-and-matching-based UAV clustering scheme to ensure that each shard and SusChain have a high consensus success rate. The simulation results show that SusChain has a significant advantage in the key indicators of sustainability. In specific cases, it has a 9–227%, 11–58%, and 27–56% improvement effect in consensus security, consensus delay, and energy consumption, compared to other sharding schemes.