A Novel zk-SNARKs Method for Cross-chain Transactions in Multi-chain System

With the deepening application of blockchain technology in the field of digital assets, the multi-chain environment combining main-chain and side-chain has gradually become mainstream. However, existing side-chain communication schemes have some shortcomings in terms of high concurrency and user privacy protection. To tackle this issue, we propose a novel zk-SNARKs method for cross-chain transactions. Specifically, we utilize non-interactive zero-knowledge proofs (zk-SNARKs) to generate respective proofs on the side-chain. These proofs are highly effective in safeguarding the specific details of the transaction, such as user information and transaction amount. We design a multi-chain system framework by introducing a relay-chain between the main-chain and multiple side-chains. The relay-chain receives proofs from the side-chains, aggregates them into a single proof using recursive zero-knowledge proofs, and then sends the aggregated proof to the main-chain. The testing experiments demonstrate that, compared with traditional methods, our proposed method improves the overall blockchain system’s throughput and reduces the workload of the main-chain while ensuring transaction privacy.