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

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.

[1]  Jean-Jacques Quisquater,et al.  Advances in Cryptology — EUROCRYPT ’95 , 2001, Lecture Notes in Computer Science.

[2]  Tor Helleseth,et al.  Advances in Cryptology — EUROCRYPT ’93 , 2001, Lecture Notes in Computer Science.

[3]  G Leuchs,et al.  Quantum key distribution with bright entangled beams. , 2002, Physical review letters.

[4]  G Leuchs,et al.  Continuous variable quantum cryptography: beating the 3 dB loss limit. , 2002, Physical review letters.

[5]  N J Cerf,et al.  Security of quantum key distribution with coherent states and homodyne detection. , 2004, Physical review letters.

[6]  Xiaolong Su,et al.  Experimental demonstration of unconditional entanglement swapping for continuous variables. , 2004, Physical review letters.