Gaussian Post-selection for Continuous Variable Quantum Cryptography

Abstract

We extend the security proof for continuous variable quantum key distribution protocols using post selection to account for arbitrary eavesdropping attacks by employing the concept of an equivalent protocol where the post-selection is implemented as a series of quantum operations including a virtual distillation. We introduce a particular `Gaussian' post selection and demonstrate that the security can be calculated using only experimentally accessible quantities. Finally we explicitly evaluate the performance for the case of a noisy Gaussian channel in the limit of unbounded key length and find improvements over all pre-existing continuous variable protocols in realistic regimes.

4+4 pages. arXiv admin note: substantial text overlap with arXiv:1106.0825

References in corpus (5)

• Unconditional optimality of Gaussian attacks against continuous-variable QKD
• Optimality of Gaussian Attacks in Continuous Variable Quantum Cryptography
• A de Finetti representation theorem for infinite dimensional quantum systems and applications to quantum cryptography
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• Security of coherent state quantum cryptography in the presence of Gaussian noise