Robust quantum dialogue based on a shared auxiliary logical Bell state against collective noise

Abstract

In this paper, two robust quantum dialogue (QD) protocols against collective-dephasing noise and collective-rotation noise are presented, respectively. In each of the proposed QD protocols, four logical Bell states, each of which is made up of four physical qubits, are used to combat collective noise. The information leakage problem is overcome by directly transmitting the auxiliary logical Bell states in two steps from one communication party to the other. For decoding, Bell state measurements rather than four-qubit joint measurements are used. The effectiveness against an eavesdroppers active attacks such as the intercept-resend attack, the measure-resend attack, the entangle-measure attack and the Trojan horse attack can be guaranteed.