Efficient Quantum Key Distribution Scheme Using the Bell State Measurement

This paper provides a quantum key distribution protocol based on the correlations of Einstein-Podolsky-Rosen (EPR) pairs. The two parties establish the key by exchanging qubits and performing the Bell state measurement. This protocol is proved to be secure because that no other people can get the key without being found. All qubits distribute to the key except those for error-checking. So the protocol is efficient.