Improving Blockchain Resilience to Network Partitioning by Sharding

A challenge overlooked in prior blockchain algorithms is that they do not consider large-scale network outages and rely on the assumption of a reliable global network connectivity. In the event of a large-scale network partition, forks may occur between partitioned regions. After the partition ends, forks will be discarded, leading to the loss of many blocks and a considerable amount of wasted work. In this paper, we propose a sharding mechanism to improve blockchain's resilience to the possibility of a global internet outage. We form consensus groups dynamically and consider the partitioning of the group as a hint to split the blockchain into branches and guarantee that all of them will be merged after the network is recovered. We indicate different methodologies to ensure blockchain security while partitioning occurs. Our experiments use simulations to show how this approach can improve the performance of blockchain algorithms and prevent wasted computational power during partitioning.