Quantum dialogue protocol with continuous-variable single-mode squeezed states

Most of the information carriers applied in the existing quantum dialogue protocols are discrete-variable quantum states. However, there are certain restrictions on the generation and detection of discrete-variable quantum states with current techniques. Continuous-variable quantum dialogue can overcome these limitations and has advantages of simple preparation, easy detection and implementation and high channel capacity. Such properties are strong improvements with respect to discrete-variable quantum dialogue. In this paper, we propose a continuous-variable quantum dialogue protocol with single-mode squeezed states. Both users in the protocol can encode their own two bits of information into optical modes with translation operations by using the phase space of a bosonic mode. The protocol improves the channel capacity as each travelling mode carries two bits of information. The security of the protocol is guaranteed by the randomly selected decoy states and encoding time slot. The protocol has been proved to be secure against information leakage problem and some common attacks.