Experimental free-space quantum secure direct communication and its security analysis

Abstract

We report an experimental implementation of free-space quantum secure direct communication based on single photons. The quantum communication scheme uses phase encoding, and the asymmetric Mach-Zehnder interferometer is optimized so as to automatically compensate phase drift of the photons during their transitions over the free-space medium. An information transmission rate of 500 bps over a 10-meter free space with a mean quantum bit error rate of 0.49%$\pm$0.27% is achieved. The security is analyzed under the scenario that Eve performs collective attack and photon number splitting collective attack. Our results show that quantum secure direct communication is feasible in free space.

References in corpus (6)

• Satellite-to-ground quantum key distribution
• Field and long-term demonstration of a wide area quantum key distribution network
• Field test of the wavelength-saving quantum key distribution network
• Quantum key distribution with triggering parametric down conversion sources
• Quantum Direct Communication with Continuous Variables
• Correction of beam wander for a free-space quantum key distribution system operating in urban environment