中文摘要：

私有信息检索是安全多方计算中重要的隐私保护问题,基于经典密码学的协议在量子计算和云计算等新型技术下十分脆弱,而现有的量子私有信息检索协议的复杂度高,在面对大型数据库时效率低下.基于目前成熟的量子密钥分发技术,提出了一种结合了密钥稀释和辅助参数两种方法的量子私有信息检索协议.协议中量子信道中只发送N个量子产生初始密钥,然后对初始密钥中连续K个比特进行按位相加去稀释初始密钥,产生最终密钥去加密数据库,并可通过灵活的选择辅助参数θ和k来保证双方隐私的安全性和提高检索成功率.可行性和性能分析结果表明,协议易于实施,一次检索成功率高,通信复杂度达到了O（N）.

英文摘要：

Private information retrieval（PIR）is an important privacy protection issue of secure multi-party computation,but the PIR protocols based on classical cryptography are vulnerable because of new technologies,such as quantum computing and cloud computing.The quantum private queries（QPQ）protocols available,however,has a high complexity and is inefficient in the face of large database.This paper,based on the QKD technology which is mature now,proposes a novel QPQ protocol utilizing the key dilution and auxiliary parameter.Only Nquits are required to be sent in the quantum channel to generate the raw key,then the straight kbits in the raw key are added bitwise to dilute the raw key,and a final key is consequently obtained to encrypt the database.By flexible adjusting of auxiliary parametersθand k,privacy is secured and the query success ratio is improved.Feasibility and performance analyses indicate that the protocol has a high success ratio in first-trial query and is easy to implement,and that the communication complexity of O（N）is achieved.