Security of coherent state quantum cryptography in the presence of Gaussian noise

Abstract

We investigate the security against collective attacks of a continuous variable quantum key distribution scheme in the asymptotic key limit for a realistic setting. The quantum channel connecting the two honest parties is assumed to be lossy and imposes Gaussian noise on the observed quadrature distributions. Secret key rates are given for direct and reverse reconciliation schemes including postselection in the collective attack scenario. The effect of a non-ideal error correction and two-way communication in the classical post-processing step is also taken into account.

12 pages, 5 figures updated version including two-way communication; changed the definition of the excess noise to match the definition given earlier (Phys. Rev. Lett. 92, 117901); submitted to PRA; presented at the 8th International Conference on Quantum Communication, Measurement and Computing, Tsukuba

References in corpus (5)

• Distillation of secret key and entanglement from quantum states
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• Optimality of Gaussian Attacks in Continuous Variable Quantum Cryptography
• Witnessing effective entanglement in a continuous variable prepare&measure setup and application to a QKD scheme using postselection
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• Explicit asymptotic secret key rate of continuous-variable quantum key distribution with an arbitrary modulation
• Asymptotic security of continuous-variable quantum key distribution with a discrete modulation
• Security of Binary Modulated Continuous Variable Quantum Key Distribution under Collective Attacks
• Feasibility of free space quantum key distribution with coherent polarization states
• Testing Quantum Devices: Practical Entanglement Verification in Bipartite Optical Systems
• Gaussian Post-selection for Continuous Variable Quantum Cryptography
• Long-distance continuous-variable measurement-device-independent quantum key distribution with post-selection