Feasible private set intersection in quantum domain

In the context of secure multi-party computation, private set intersection (PSI) is an important cryptographic primitive for performing joint operations on datasets in a privacy preserving manner. In particular, it allows the participants to privately determine the intersection of their private datasets. Most of the existing PSI protocols are based on traditional classical cryptosystems, which are proven to be vulnerable in quantum domain. This makes the requirement of quantum computer resistant PSI. Applying quantum cryptography in the design of PSI is an ideal approach to address these issues. In this paper, we present a quantum PSI (QPSI) relying on the basic quantum mechanics principles, which are resistant against well-known quantum attacks. Quantum resources in our QPSI are considered as single photons and we require to perform only simple single-particle projective measurements. These features make our QPSI more feasible to implement with the present technology, compared to the existing QPSI protocols, which adopt multi-particle entangled states and complicated quantum operators. On a more positive note, in our QPSI, only one time quantum communication and quantum computation allows execution of set intersection functionality multiple number of times, provided the client’s set size remains same, while the existing QPSI protocols do not achieve this property.