Private Set Intersection (PSI) is a vital cryptographic technique used for securely computing common data of different sets. In PSI protocols, often two parties hope to find their common set elements without needing to disclose their uncommon ones. In recent years, the cloud has been playing an influential role in PSI protocols which often need huge computational tasks. In 2017, Abadi et al. introduced a scheme named EO-PSI which uses a cloud to pass on the main computations to it and does not include any public-key operations. In EO-PSI, parties need to set up secure channels beforehand; otherwise, an attacker can easily eavesdrop on communications between honest parties and find private information. This paper presents an improved EO-PSI scheme which has the edge on the previous scheme in terms of privacy and complexity. By providing possible attacks on the prior scheme, we show the necessity of using secure channels between parties. Also, our proposed protocol is secure against passive attacks without having to have any secure channels. We measure the protocol's overhead and show that computational complexity is considerably reduced and also is fairer compared to the previous scheme.
翻译:在《防扩散安全倡议议定书》中,常常有两方希望找到共同的集合要素,而不必披露其非同寻常的集合要素。近年来,云在《防扩散安全议定书》中一直发挥着有影响力的作用,这些协议往往需要大量的计算任务。2017年,Abadi等人推出了一个名为EO-PSI的计划,该计划使用云来传递主要计算结果,并不包括任何公用钥匙操作。在《欧洲安全安全倡议》中,各方需要事先建立安全渠道;否则,攻击者可以很容易地窃听诚实方之间的通信并找到私人信息。该文件展示了一个改进的 EO-PSI计划,该计划在隐私和复杂性方面与以前的计划相比具有优势。我们通过提供对先前计划可能的袭击,表明有必要使用双方之间的安全渠道。此外,我们提出的协议可以在不需要任何安全渠道的情况下防止被动攻击。我们测量协议的间接费用,并表明计算复杂性大大降低,而且与前计划相比更为公平。