Developing a fair, efficient, and scalable data trading protocol in decentralized networks has attracted much research effort recently. Zero-knowledge contingent payments (ZKCP) allows sellers and buyers to complete their trade fairly over the blockchain using zero-knowledge proofs. However, it suffers from memory-intensive requirements and scalability limitations. In this paper, we propose a practical data trading protocol tailored for Sudoku solutions, which is fair, efficient, and scalable. The core component of our protocol is a zero-knowledge argument for the correctness of a Sudoku solution of homomorphic encryption. This argument achieves sublinear communication complexity and the number of group exponentiations for both proving and verification is linear in the size of Sudoku solutions. The security of our protocol can be proven in the random oracle model under the Decision Diffie-Hellman assumption. In addition, we devise a mechanism that allows buyers to recover the private key through two zero-knowledge proofs and prevents the direct exposure of the decryption key. Furthermore, we implement the proposed protocol on the Ethereum testnet, and the experimental results show a significant improvement in overall efficiency.

中文翻译：

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数独解决方案的实用数据交易协议


在去中心化网络中开发公平、高效、可扩展的数据交易协议最近吸引了大量的研究工作。零知识或有支付（ZKCP）允许卖家和买家使用零知识证明在区块链上公平地完成交易。然而，它面临内存密集型要求和可扩展性限制。在本文中，我们提出了一种为数独解决方案量身定制的实用数据交易协议，该协议公平、高效且可扩展。我们协议的核心组成部分是对同态加密数独解决方案正确性的零知识论证。该论点实现了次线性通信复杂性，并且用于证明和验证的组幂数与数独解决方案的大小呈线性关系。我们协议的安全性可以在决策 Diffie-Hellman 假设下的随机预言模型中得到证明。此外，我们设计了一种机制，允许买家通过两个零知识证明恢复私钥，并防止解密密钥直接暴露。此外，我们在以太坊测试网上实现了所提出的协议，实验结果表明整体效率显着提高。