An efficient deterministic secure quantum communication scheme based on cluster states and identity authentication

A novel efficient deterministic secure quantum communication schemebased on four-qubit cluster states and single-photon identityauthentication is proposed. In this scheme, the two authenticatedusers can transmit two bits of classical information per clusterstate, and its efficiency of the quantum communication is 1/3, whichis approximately 1.67 times that of the previous protocol presentedby Wang et al [Chin. Phys. Lett. 23 (2006) 2658].Security analysis shows the present scheme is secure againstintercept-resend attack and the impersonator's attack. Furthermore,it is more economic with present-day techniques and easily processedby a one-way quantum computer.