HD-OCC: High-Performance Deterministic OCC Protocal for Sharded Blockchains

Abstract

As blockchain evolves toward complex Decentralized Finance (DeFi) applications, traditional serial execution becomes a primary bottleneck. Sharding offers a promising Layer-1 scaling solution but trades off cross-shard atomicity and execution latency. Existing solutions enforcing strong consistency via global sequencing or heavy two-phase commit (2PC) often suffer from high latency and resource redundancy. We propose HD-OCC, a high-performance framework combining deterministic execution with assertion-based Optimistic Concurrency Control (OCC). HD-OCC utilizes Proof of History$(\text{PoH})$for a dual-layer sequencing architecture, establishing a global partial order that decouples local processing from global consensus. Our assertion-based OCC enables the coordinator to speculatively execute transactions while parallelizing resource locking to mask network latency. Additionally, a deterministic scheduling engine implicitly constructs a deadlock-free dependency graph. Experimental results demonstrate that HD-OCC achieves linear throughput scalability and significantly lower end-to-end latency compared to monolithic architectures and deterministic systems like Calvin.