Secure cross-chain interactions: a relay chain framework with privacy and auditability solutions

Recent advancements in blockchain technology have heightened interest in enabling information transfer and value exchange across different blockchains. To address asset and data interoperability challenges, cross-chain technology has emerged, though it often risks transaction privacy leakage. This paper presents a relay chain-based cross-chain model that facilitates operations through the relay chain while storing generated information on-chain, ensuring traceability. A privacy protection scheme and a verifiable multi-node key-sharing method are proposed, employing cryptographic techniques to safeguard transaction privacy. In case of disputes, privacy information can be decrypted via the relay chain for auditability. The paper includes a detailed analysis and performance testing of the proposed solution, comparing it with other existing privacy-preserving relay chain solutions, and evaluates the delay performance of the key-sharing algorithm, showcasing its security and feasibility advantages.