Quantum Key Distribution and Quantum Authentication Based on Entangled State

Using the previously shared Einstein-Podolsky-Rosen pairs, a proposal which can be used to distribute a quantum key and identify the user's identification simultaneously is presented. In this scheme, two local unitary operations and the Bell state measurement are used. Combined with quantum memories, a cryptographic network is proposed. One advantage is no classical communication is needed, which make the scheme more secure. The secure analysis of this scheme is shown.Comment: Revtex, 9 pages, no figure, accepted for publication by Phys. Lett.