The invention discloses a
Bell state and rotation operation-based practical
quantum privacy comparison protocol method, which comprises the following steps that: a semi-honest
third party prepares S and records the state of the S, and first particles and second particles in all Bell states are respectively utilized to form S1 and S2; first
eavesdropping detection is carried out, if the first
eavesdropping detection passes, the first participant and the second participant respectively obtain S1 and S2, and the next step is continued, otherwise, communication is stopped; the first participant and the second participant act rotation operations Ry (piX) and Ry (piY) on the S1 and the S2 respectively to obtain SA and SB and send the SA and the SB to the semi-honest
third party; the semi-honest
third party sequentially executes Bell-based measurement on the SA and the SB to obtain a measurement result, if the measurement result is consistent with the
quantum sequence S, the semi-honest third party declares that the privacy information of the first participant and the privacy information of the second participant are the same, otherwise, the privacy information of the first participant and the privacy information of the second participant are different. According to the method, possible
information leakage is effectively prevented, the capability of resisting external and internal attacks of the method provided by the invention is remarkably enhanced, and the technical threshold and the cost of implementation are greatly reduced.