HiCoCS: High Concurrency Cross-Sharding on Permissioned Blockchains

2025-01-08

AI Summary

Existing blockchain sharding systems suffer from severe account-level conflicts, limited throughput, complex auxiliary key management, and high privacy leakage risks under high-concurrency cross-shard transactions (CSTxs). This paper targets permissioned blockchains and proposes a concurrency control mechanism based on composite keys and virtual sub-agents. For each CSTx, a lightweight virtual sub-agent is dynamically instantiated; the mechanism integrates multi-version concurrency control (MVCC), composite key reuse, batched transaction merging, and homomorphic encryption to ensure conflict-free execution while significantly reducing resource overhead and mitigating intermediary privacy risks. Experimental results demonstrate that the approach improves CSTx throughput by 3.5–20.2×, effectively alleviates account contention, and— for the first time—achieves synergistic optimization of security, efficiency, and privacy under high-concurrency CSTx workloads.

Technology Category

• Multiagent Systems: Mechanism Design
• Data Mining & Knowledge Management: Scalability, Parallel & Distributed Systems
• Cognitive Modeling & Cognitive Systems: Agent Architectures

Application Category

• Security and Privacy: Blockchains and distributed ledgers
• Systems and Infrastructure for Web, Mobile and WoT: Virtualization and resource management in Web systems and infrastructures
• Economics, Online Markets and Human Computation: Economic aspects of blockchain and cryptocurrencies

Abstract

As the foundation of the Web3 trust system, blockchain technology faces increasing demands for scalability. Sharding emerges as a promising solution, but it struggles to handle highly concurrent cross-shard transactions ( extsf{CSTx}s), primarily due to simultaneous ledger operations on the same account. Hyperledger Fabric, a permissioned blockchain, employs multi-version concurrency control for parallel processing. Existing solutions use channels and intermediaries to achieve cross-sharding in Hyperledger Fabric. However, the conflict problem caused by highly concurrent extsf{CSTx}s has not been adequately resolved. To fill this gap, we propose HiCoCS, a high concurrency cross-shard scheme for permissioned blockchains. HiCoCS creates a unique virtual sub-broker for each extsf{CSTx} by introducing a composite key structure, enabling conflict-free concurrent transaction processing while reducing resource overhead. The challenge lies in managing large numbers of composite keys and mitigating intermediary privacy risks. HiCoCS utilizes virtual sub-brokers to receive and process extsf{CSTx}s concurrently while maintaining a transaction pool. Batch processing is employed to merge multiple extsf{CSTx}s in the pool, improving efficiency. We explore composite key reuse to reduce the number of virtual sub-brokers and lower system overhead. Privacy preservation is enhanced using homomorphic encryption. Evaluations show that HiCoCS improves cross-shard transaction throughput by 3.5-20.2 times compared to the baselines.

Problem

• Blockchain Sharding
• Cross-Shard Transactions
• Concurrency Control

Innovation

• HiCoCS
• Cross-Shard Transactions
• Concurrency Optimization