High-Capacity Quantum Private Comparison Protocol With Six-Qubit Hyperentangled Bell States and Hypercoding

Based on the two-photon six-qubit hyperentangled Bell states and hyper-coding, a new high-capacity quantum privacy comparison (QPC) protocol is proposed to realize a high utilization of quantum resources. The protocol enables two particles of hyperentangled Bell states to compare the equality of 6 classical bits of secret information between two quantum users. The unitary operations are used to encode the secret information and achieve dense coding. In the proposed protocol, decoy photons and the quantum uncertainty principle are used to ensure transmission channel security and particle security. comparisons with other QPC protocols in terms of quantum resources and efficiency reveal that the proposed protocol has significant advantages in quantum efficiency.