Abstract: Blockchain technology leverages distributed ledgers and cryptographic techniques to offer novel solutions for data privacy and transaction security. Among various cross-chain solutions, the notary group-based model has been widely adopted for data exchange across various domains. However, the centralized architecture of traditional notary group models introduces inherent risks and remains susceptible to network fluctuations. To address the centralization issue in notary-based cross-chain technologies, this paper proposes a novel transaction protocol jointly designed by notaries. First, an improved PageRank algorithm is introduced to reduce centralization during notaries selection process. Then, a sub-secret segment table scheme is proposed to optimize the threshold signature algorithm, thereby enhancing the protocol’s robustness under network fluctuations while preserving decentralization. Experimental results show that with 50 participating notaries, the optimized node selection algorithm improves the overall balance of node reputation values by 47.3% compared to traditional approaches. Moreover, under a network packet loss rate of up to 70%, the optimized threshold signature algorithm achieves approximately three times the robustness of standard threshold signature schemes, with negligible additional time overhead and Gas costs. Overall, the proposed protocol significantly enhances decentralization and robustness of cross-chain transactions with minimal impact on transaction costs, demonstrating its practical feasibility.

Key words: cross-chain, notary group, decentralization, transaction, risk resistance