Transaction Processing in Blockchain Sharding: Current Trends and Future Research Directions
Ramesh Adhikari, Costas Busch, Dariusz Rafal Kowalski, Abdullah Al-Mamun · Distributed Ledger Technologies Research and Practice · 2025
Blockchain is known for its promising features, such as decentralization, fault tolerance, transparency, and immutability. Thus, it has been used in many industries and applications, including cryptocurrency, finance, smart cities, healthcare, and manufacturing. However, blockchain suffers from scalability issues and provides low transaction throughput and high latency. Sharding is used to solve these scalability and performance issues by dividing the blockchain network into smaller clusters of nodes called shards, and each shard processes transactions in parallel. However, the sharding protocol is still in its early stages and encounters multiple challenges. In this article, we survey cutting-edge blockchain sharding articles, mainly focusing on transaction processing aspects such as intra-shard transaction processing, cross-shard communication, and cross-shard transaction processing. We also examine security vulnerabilities and attack vectors associated with sharded blockchain systems. We review existing techniques, highlight key challenges and problems, and suggest potential future research directions.