Data outsourcing has become a popular application. Searchable encryption (SE) can provide data retrievability as well as keep data privacy. In the threat model of SE schemes, the cloud server is usually assumed to be Honest-But-Curious, but this may not be true in reality. The blockchain-based SE makes malicious cloud servers dare not to deviate from the protocol, and search results are validated by miners. However, rational miners would skip the validation step and accept the block directly to save computational resources. This situation is called the Verifier’s Dilemma which will make the blockchain-based SE scheme not real verifiable. Therefore, this paper proposes a verifiable blockchain-based public-key encryption scheme that outsources the verification to the TrueBit network. This design makes our scheme achieves effective verifiability which will minimize the computational cost of miners. Furthermore, our scheme also establishes a fair payment protocol between the multiple data owners and data users. Also, the data owner can revoke the permission of the document he/she shared before. We also present security proofs and analysis of the proposed scheme. Performance evaluation presents the overheads of performing search operations on the cloud server and conducting transactions on smart contracts in Ethereum. The experiment results demonstrate the practicability of our proposed scheme.

数据外包已成为一种流行的应用程序。可搜索加密（SE）可以提供数据可检索性并保持数据隐私。在SE方案的威胁模型中，通常将云服务器假定为“诚实但好奇”，但这在现实中可能并非如此。基于区块链的SE使恶意云服务器不敢偏离协议，并且搜索结果已由矿工验证。但是，有理性的矿工将跳过验证步骤并直接接受该块以节省计算资源。这种情况称为验证者困境这将使基于区块链的SE方案无法真正验证。因此，本文提出了一种基于可验证的基于区块链的公钥加密方案，该方案将验证工作外包给TrueBit网络。这种设计使我们的方案能够实现有效的可验证性，从而将矿工的计算成本降至最低。此外，我们的方案还建立了多个数据所有者和数据用户之间的公平支付协议。同样，数据所有者可以撤消他/她之前共享的文档的权限。我们还提供了安全证明和对建议方案的分析。性能评估显示了在云服务器上执行搜索操作以及在以太坊中进行智能合约交易的开销。实验结果证明了该方案的实用性。