Volume 87, Number 2, July 2009
Article Number 20005
Number of page(s) 6
Section General
Published online 18 August 2009
EPL, 87 (2009) 20005
DOI: 10.1209/0295-5075/87/20005

Continuous variable quantum key distribution based on optical entangled states without signal modulation

Xiaolong Su, Wenzhe Wang, Yu Wang, Xiaojun Jia, Changde Xie and Kunchi Peng

The State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University - Taiyuan, 030006, PRC

received 3 March 2009; accepted in final form 17 July 2009; published July 2009
published online 18 August 2009

In this paper, we present the first experimental demonstration on continuous variable quantum key distribution using determinant Einstein-Podolsky-Rosen entangled states of optical field. By means of the instantaneous measurements of the quantum fluctuations of optical modes, respectively, distributed at sender and receiver, the random bits of secret key are obtained without the need for signal modulation. The post-selection boundaries for the presented entanglement-based scheme against both Gaussian collective and individual attacks are theoretically concluded. The final secret key rates of 84 kbits/s and 3 kbits/s are completed under the collective attack for the transmission efficiency of 80% and 40%, respectively.

03.67.Dd - Quantum cryptography and communication security.
42.50.-p - Quantum optics.
03.67.Mn - Entanglement measures, witnesses, and other characterizations.

© EPLA 2009