As a trusted middleware connecting the blockchain and the real world, the blockchain oracle can obtain trusted real-time price information for financial applications such as payment and settlement, and asset valuation on the blockchain. However, the current oracle schemes face the dilemma of security and service quality in the process of node selection, and the implicit interest relationship in financial applications leads to a significant conflict of interest between the task publisher and the executor, which reduces the participation enthusiasm of both parties and system security. Therefore, this paper proposes an anonymous node selection scheme that anonymously selects nodes with high reputations to participate in tasks to ensure the security and service quality of nodes. Then, this paper also details the interest requirements and behavioral motives of all parties in the payment settlement and asset valuation scenarios. Under the assumption of rational participants, an incentive mechanism based on the Stackelberg game is proposed. It can achieve equilibrium under the pursuit of the interests of task publishers and executors, thereby ensuring the interests of all types of users and improving the enthusiasm of participation. Finally, we verify the security of the proposed scheme through security analysis. The experimental results show that the proposed scheme can reduce the variance of obtaining price data by about 55\% while ensuring security, and meeting the interests of all parties.

翻译：作为连接区块链与真实世界的可信中间件，区块链预言机能够为链上的支付结算、资产估值等金融应用提供可信的实时价格信息。然而，现有预言机方案在节点选择过程中面临安全性与服务质量的困境，且金融应用中隐含的利益关系导致任务发布者与执行者存在显著利益冲突，降低了双方参与积极性与系统安全性。为此，本文提出一种匿名节点选择方案，通过匿名选取高信誉节点参与任务以确保节点安全性与服务质量。随后，本文详细阐述了支付结算与资产估值场景中所有参与方的利益需求与行为动机，在理性参与者假设下提出基于Stackelberg博弈的激励机制。该机制能够在任务发布者与执行者的利益追求下达到均衡，从而保障各类用户利益并提升参与积极性。最后，通过安全性分析验证了所提方案的安全性。实验结果表明，所提方案在保障安全性的同时可将获取价格数据的方差降低约55%，并满足各方利益诉求。