Abstract
The introduction of Bitcoin cryptocurrency has inspired businesses and researchers to investigate into the technical aspects of blockchain and DLT systems. However, the blockchain technologies today still have distinct limitations on scalability and flexibly in terms of large-size and dynamic reconfigurability. Sharding appears to be a promising solution to scale out the blockchain system horizontally by dividing the entire network into multiple shards or clusters. However, flexibility and reconfigurability of these clusters need further research and investigations. In this paper, we propose two efficient mechanisms to enable flexible dynamic re-clustering of the blockchain network including blockchain cluster merging and splitting operations. Such mechanisms offer a solution to specific application scenarios such as microgrids and other edge-based applications where clusters of autonomous systems potentially require structure reconfigurations. The proposed mechanisms offer three-stage procedures to merge and split multiple clusters. Based on our simulation experiments, we show that the proposed merging and splitting operations based on proof of work (PoW) consensus algorithm can be optimized to reduce the merging time considerably (in the magnitude of 1/22000 based on 100 blocks) which effectively reduces overall merging and splitting completion time, interruption time and required computation power.