Efficient Quantum Private Comparison Using Locally Indistinguishable Orthogonal Product States

Abstract

AbstractIn this paper, an efficient quantum private comparison (QPC) for equality comparison using locally indistinguishable orthogonal product states is proposed. In the proposed protocol, two participants can compare the equality of three classical bits in each comparison, which could greatly reduce comparison times and improve efficiency. A semi-honest third party (TP) is involved to help two participants compare the equality of their secrets and she may misbehave on her own, but she is not allowed to conspire with any participants. Additionally, the security analysis shows that the proposed QPC protocol is secure against both outside attacks and participant ones. Compared with the existing QPC protocols, the proposed protocol needs neither swapping entanglement technology nor unitary operations, in which quantum devices are expensive and difficult to implement. Finally, it is generalized to multi-party QPC (MQPC) protocol.KeywordsQuantum cryptographyQuantum private comparisonLocal indistinguishabilityOrthogonal product statesSemi-honest third-party