An Overlapping Self-Organizing Sharding Scheme Based on DRL for Large-Scale IIoT Blockchain.

Sharding is widely regarded as a highly promising solution to address the scalability limitations of blockchain. However, the scalability and throughput improved by using sharding are limited by the verification of cross-shard transactions. To reduce cross-shard transaction and improve the throughput of the blockchain, the existing sharding schemes are based on factors such as the edge-end structure of IIoT for sharding. But these schemes are centralized, leading to the problems of low sharding efficiency, poor scalability and poor security. Moreover, these schemes adopt a non-overlapping sharding architecture, so the verification cost of cross-shard transactions is significantly higher than that of intra-shard transactions. In order to solve the above problems, this paper proposes an overlapping self-organizing sharding scheme (DRL-OSS) for large-scale IIoT blockchain. Based on local blockchain information such as nodes’ information and transaction interaction frequency, DRL-OSS uses DRL to achieve self-organizing sharding with the aim to maximize the throughput and security of blockchain. In addition, based on the threat model, this paper also designs a block complaint scheme to further improve the security of the blockchain, thereby avoiding the reduction in resistance to 1% attack due to the poor anti-predictability of shards and the dilution of computing power. Through experimental verification and analysis, DRL-OSS improves the throughput by 50% when compared to state-of-the-art sharding schemes and has higher system security.