This paper proposes two quantum privacy query protocols. In the single vector sub-privacy query of protocol 1, it is proposed for the first time to distinguish different measurement results by publishing 2 bits of classic information. In the protocol, the database Bob selects the Z base and the Bell base to measure the particles sent by Alice according to the key value of the encrypted database and publishes 2 bits of classic information based on the measurement results. The user Alice infers the key value of the encrypted database through these two pieces of classic information. In the two-way quantum privacy query of protocol 2, the database Bob measures the particles sent back by Alice, converts the measurement result into a key value of length 3, and prepares a particle that is the same as the measurement result and sends it back to Alice. Alice returns the measurement of particles can infer a set of data encryption keys, and the length of each key is 3 bits. Users in the two protocols proposed in the article can obtain the query key with a probability of 1/4. As the key length increases, the number of query bits in protocol 2 decreases, but the probability of execution failure increases. But protocol 2 has a higher quantum efficiency. Both protocols can guarantee the privacy of users and databases.

中文翻译：

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两种基于贝尔态和单光子的量子私有查询协议

本文提出了两种量子隐私查询协议。在协议一的单向量子隐私查询中，首次提出通过发布2比特经典信息来区分不同的测量结果。在协议中，Bob 数据库根据加密数据库的密钥值选择 Z 基和 Bell 基对 Alice 发送的粒子进行测量，并根据测量结果发布 2 位经典信息。用户 Alice 通过这两条经典信息推断出加密数据库的密钥值。在协议2的双向量子隐私查询中，数据库Bob对Alice发回的粒子进行测量，将测量结果转换为长度为3的key值，准备一个与测量结果相同的粒子发送出去回到爱丽丝。Alice 返回的粒子测量可以推断出一组数据加密密钥，每个密钥的长度为 3 位。文中提出的两种协议中的用户可以以 1/4 的概率获得查询密钥。随着密钥长度的增加，协议 2 中的查询位数减少，但执行失败的概率增加。但协议 2 具有更高的量子效率。两种协议都可以保证用户和数据库的隐私。但协议 2 具有更高的量子效率。两种协议都可以保证用户和数据库的隐私。但协议 2 具有更高的量子效率。两种协议都可以保证用户和数据库的隐私。