Fault Tolerant Authenticated Quantum Dialogue Based on Logical Qubits and Controlled-Not Operations

Abstract

In this paper, two fault tolerant authenticated quantum dialogue (AQD) protocols against the collective-dephasing noise and the collective-rotation noise are constructed, respectively, by using logical qubits and controlled-not (CNOT) operations. The proposed protocols can accomplish the mutual identity authentications between two communicants before decoding and overcome the information leakage problem. The quantum measurements throughout the proposed protocols can be simplified into the single-photon measurements. Moreover, they have the information-theoretical efficiency as high as 50%. Different from the recent fault tolerant QD protocols generating two adjacent logical qubits in the same state, the proposed protocols do not have this special requirement.