Continuous Variable Quantum Key Distribution: Finite-Key Analysis of   Composable Security against Coherent Attacks
  We provide a security analysis for continuous variable quantum key distribution protocols based on the transmission of squeezed vacuum states measured via homodyne detection. We employ a version of the entropic uncertainty relation for smooth entropies to give a lower bound on the number of secret bits which can be extracted from a finite number of runs of the protocol. This bound is valid under general coherent attacks, and gives rise to keys which are composably secure. For comparison, we also give a lower bound valid under the assumption of collective attacks. For both scenarios, we find positive key rates using experimental parameters reachable today. 
Fabian Furrer, Torsten Franz, Mario Berta, Anthony Leverrier, Volkher   B. Scholz, Marco Tomamichel, Reinhard F. Werner
quant-ph