| 摘要 |
Secure, semi-classical authentication schemes are presented. The schemes do not rely on lengthy storage of quantum states. A plurality of random quantum states chosen from a set of non-orthogonal states is generated at a first space-time point P, and transmitted. The receiver of the quantum states applies a pre-determined measurement to obtain a token that comprises a sequence of classical measurement outcomes. The token is presented by the receiver to the transmitter for validation at a second space-time point Q in the causal future of the first space-time point P. The token is verified by checking its correspondence to a statistically plausible result for the predetermined measurement of the quantum states. A successful verification allows the receiver access to a resource. Each of the plurality of quantum states may comprise a BB84 state and the plurality of quantum states may be entangled. The quantum states may represent qubits with each qubit represented by the polarisation state of a weak light pulse with low expected photon number. |
