BEST: A blockchain sharding scheme based on nodes performance for enhancing both security and effiency

Abstract Sharding technology is seen as the most likely solution to the scalability of blockchain, by dividing nodes into smaller groups called shards that transactions can be processed in parallel. However, most sharding scheme adopted random sharding to avoid the aggregation of malicious nodes, while the performance difference between nodes is ignored, resulting in the transaction efficiency gap of each sharding. In this paper, we propose BEST, a blockchain sharding scheme with both security and effiency, nodes are allocated to a shard according to the reputation score, which guarantees the consistent comprehensive performance of each shard. A multi-attribute leader decision model is established instead of randomly selecting leader nodes. We verify the scheme through theoretical analysis and experimental evaluation, and the results show that the proposed scheme improves the parallel throughput of the system while ensuring system security.