Segment-Account Migration: Efficient Account Migration Based on Lock-Free Mechanism

Abstract

Blockchain represents a critical technical solution for achieving reliable and trustworthy distributed storage in JointCloud computing. Sharding technology can enhance the scalability of blockchain. However, while improving throughput, the massive cross-shard transactions introduced by sharding have become a new performance bottleneck. To mitigate this problem, state-of-the-art studies have adopted account migration strategies to reduce the amount of cross-shard transactions, nevertheless, prevailing methodologies depend on lock mechanisms that result in significant latency overhead for locked transactions. This work proposes Segment-Account Migration (SAM), an efficient lock-free account migration protocol by segmenting the account balance, retaining a portion on the source shard to support payer transactions while transferring the remainder and the account state to the target shard, thereby eliminating transaction locks during migration. Furthermore, the SAM protocol introduces a time window-based rollback mechanism to handle migration failures and defend against replay attacks. Experiments on the Ethereum dataset demonstrate that SAM reduces the average completion time of related-party transactions by 24.85% and decreases the average amount of state synchronization data by 34.65%. This significant improvement enhances migration efficiency while maintaining security, offering a reliable and effective solution for the scalability of sharded blockchains.