Improvement of secure communication with continuous variable entanglement of squeezed coherent states via heterodyne detection

In this paper, we propose a continuous variable quantum key distribution protocol based on entanglement of a squeezed coherent state and reverse reconciliation. We present a rigorous security proof against individual and collective attacks with realistic lossy, noisy quantum channels, imperfect detector efficiency and detector electronic noise. This protocol is promising for convenient, high-speed operation at link distances to over 50 km. The setup can be further improved in terms of key generation rate and distance by inserting a noiseless phase-sensitive amplifier at the legitimate receiver Bob's input in order to compensate for the inherent imperfection of heterodyne detection.