wChain: A Fast Fault-Tolerant Blockchain Protocol for Multihop Wireless Networks.

This paper presents $\mathit {wChain}$ , a blockchain protocol specifically designed for multihop wireless networks that deeply integrates wireless communication properties and blockchain technologies under the realistic SINR model. We adopt a hierarchical spanner as the communication backbone to address medium contention and achieve fast data aggregation within $O(\log N\log \Gamma)$ slots where $N$ is the network size and $\Gamma $ refers to the ratio of the maximum distance to the minimum distance between any two nodes. Besides, $\mathit {wChain}$ employs data aggregation and reaggregation as well as node recovery mechanisms to ensure efficiency, fault tolerance, persistence, and liveness. The worst-case runtime of $\mathit {wChain}$ is upper bounded by $O(f\log N\log \Gamma)$ , where $f=\lfloor \frac {N}{2} \rfloor $ is the upper bound of the number of faulty nodes. To validate our design, we conduct both theoretical analysis and simulation studies. The results not only demonstrate the nice properties of $\mathit {wChain}$ , but also point to a large new space for the exploration of blockchain protocols in wireless networks. [ABSTRACT FROM AUTHOR]