A Trusted Third-Party E-Payment Protocol Based on Locally Indistinguishable Orthogonal Product States

We propose an electronic payment (E-payment) protocol with a trusted third-party. Quantum key distribution protocol, single-particle unitary operation, one-time pad and orthogonal product states (OPSs) which are locally indistinguishable, are used to ensure the protocol’s security. In our protocol, the information that needs to be transmitted is encoded as a quantum sequence of OPSs that cannot be precisely discriminated by local operations and classical communication (LOCC). All the particles of each OPS are transmitted in a separate way, which can guarantee the protocol’s security. In addition, once there is a dispute among the participants, a trusted third party Trent will resolve the dispute.