Most existing quantum private query (QPQ) protocols can hardly work in the presence of noise. The user Alice may obtain a false database item in noisy environments and both participants may cheat under the disguise of noise, so dealing with the noise needs an overall consideration of error correction, user privacy and database security. However, the only two existing protocols aiming to correct errors in QPQ lack such an overall consideration (at least one party’s privacy can be revealed), and they did not estimate what extent of errors can be tolerated (actually, noise is seldom discussed in quantum two-party secure computations, and to the best of our knowledge, relevant bounds on tolerable errors remain unattainable so far). To solve this problem, we first exemplify how one participant reveals the other party’s privacy in the existing QPQ protocols aiming to correct errors. Then we propose a practical protocol which can really work via noisy channel, that is, the error rate of the retrieved database item is reduced significantly and both parties’ privacy are well protected. Besides, we deduce that the final error rate, user privacy and database security are pairwise in a “trade-off” relationship. By balancing them according to the required level of security and reliability, we obtain an upper bound on tolerable errors.

中文翻译：

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基于 QKD 的量子私有查询中的容错边界

大多数现有的量子私有查询 (QPQ) 协议在存在噪声的情况下几乎无法工作。用户Alice在嘈杂的环境中可能会得到一个虚假的数据库项，参与者双方都可能在噪声的伪装下作弊，因此处理噪声需要综合考虑纠错、用户隐私和数据库安全。然而，现有的仅有两个旨在纠正 QPQ 错误的协议缺乏这样的整体考虑（至少可以泄露一方的隐私），并且他们没有估计可以容忍的错误程度（实际上，量子中很少讨论噪声）两方安全计算，据我们所知，到目前为止，可容忍错误的相关界限仍然无法实现）。为了解决这个问题，我们首先举例说明一个参与者如何在旨在纠正错误的现有 QPQ 协议中透露另一方的隐私。然后我们提出了一个实用的协议，它可以真正通过噪声信道工作，即检索到的数据库项的错误率显着降低，双方的隐私得到很好的保护。此外，我们推断出最终错误率、用户隐私和数据库安全是成对的“权衡”关系。通过根据所需的安全性和可靠性级别平衡它们，我们获得了可容忍错误的上限。我们推断出最终的错误率、用户隐私和数据库安全是成对的“权衡”关系。通过根据所需的安全性和可靠性级别平衡它们，我们获得了可容忍错误的上限。我们推断出最终的错误率、用户隐私和数据库安全是成对的“权衡”关系。通过根据所需的安全性和可靠性级别平衡它们，我们获得了可容忍错误的上限。