Cross-Chain Asset Transfer Using Secure State Snapshots and Optimistic Verification

Abstract

Cross-chain interoperability is essential for the next generation of decentralized finance applications, yet existing bridges suffer from security weaknesses, high latency, and fragmented trust models. This paper introduces SnapBridge, a protocol that transfers assets across heterogeneous blockchains using cryptographic state snapshots combined with optimistic verification. A snapshot aggregator collects Merkleized proofs of account states and transaction histories from the source chain. Instead of verifying all proofs on-chain, SnapBridge relies on optimistic execution: transfers proceed immediately but can be challenged within a fraud-proof window. Fraud detection is performed by light clients using succinct verification rules. We implement SnapBridge across Ethereum, Polygon, and Avalanche testnets and benchmark transfer throughput, failure handling, and gas consumption. Results show up to 3× improvement in transfer latency and a 40% reduction in on-chain verification cost compared to multisig-based bridges. The paper evaluates adversarial scenarios such as corrupted aggregators, delayed snapshots, and chain reorgs. SnapBridge provides a modular, safer alternative for cross-chain liquidity flows.