Two Semi-Quantum Private Comparison Protocols of Size Relation Based on Single Particles

With d-dimensional single photons, two semi-quantum private comparison protocols are presented to compare the size relation between two classical parties' private secrets. The first protocol transmits particles with the distribution model, whereas the second one transmits particles with the circle model. In the two designed protocols, it is not necessary for the classical participants to possess the abilities to measure quantum states, which greatly reduces the consumption of quantum resources. It is demonstrated that the output results of the two presented semi-quantum private comparison protocols are correct, and the private secrets of participants will not be leaked out to others. Security analyses indicate that the two proposed semi-quantum private comparison protocols could counteract some common attacks, including external attacks and participant attacks.