SP-Chain: Boosting Intra-Shard and Cross-Shard Security and Performance in Blockchain Sharding

TL;DR

SP-Chain is a blockchain sharding system that enhances security and performance both within shards and across shards, achieving high throughput and low latency even under malicious conditions.

Contribution

The paper introduces SP-Chain, a novel sharding protocol with innovative voting, leader rotation, and cross-shard transaction mechanisms for improved security and efficiency.

Findings

Processes over 10,000 transactions/sec under malicious behaviors.

Achieves 7.6 seconds confirmation latency in large-scale deployment.

Demonstrates high security and performance in 4,000-node network.

Abstract

A promising way to overcome the scalability limitations of the current blockchain is to use sharding, which is to split the transaction processing among multiple, smaller groups of nodes. A well-performed blockchain sharding system requires both high performance and high security in both intra- and cross-shard perspectives. However, existing protocols either have issues on protecting security or trade off great performance for security. In this paper, we propose SP-Chain, a blockchain sharding system with enhanced Security and Performance for both intra- and cross-shard perspectives. For intra-shard aspect, we design a two-phase concurrent voting scheme to provide high system throughput and low transaction confirmation latency. Moreover, we propose an efficient unbiased leader rotation scheme to ensure high performance under malicious behavior. For cross-shard aspect, a proof-assisted efficient cross-shard transaction processing mechanism is proposed to guard the cross-shard transactions with low overhead. We implement SP-Chain based on Harmony, and evaluate its performance via large-scale deployment. Extensive evaluations suggest that SP-Chain can process more than 10,000 tx/sec under malicious behaviors with a confirmation latency of 7.6s in a network of 4,000 nodes.