Composable security proof for continuous-variable quantum key distribution with coherent states

Abstract

We give the first composable security proof for continuous-variable quantum key distribution with coherent states against collective attacks. Crucially, in the limit of large blocks the secret key rate converges to the usual value computed from the Holevo bound. Combining our proof with either the de Finetti theorem or the Postselection technique then shows the security of the protocol against general attacks, thereby confirming the long-standing conjecture that Gaussian attacks are optimal asymptotically in the composable security framework. We expect that our parameter estimation procedure, which does not rely on any assumption, will find applications elsewhere, for instance for the reliable quantification of continuous-variable entanglement in finite-size settings.

27 pages, 1 figure. v2: added a version of the AEP valid for conditional states

References in corpus (13)

• Unconditional optimality of Gaussian attacks against continuous-variable QKD
• Quantum key distribution over 25 km with an all-fiber continuous-variable system
• Optimality of Gaussian Attacks in Continuous Variable Quantum Cryptography
• Finite-size analysis of continuous-variable quantum key distribution
• A de Finetti representation theorem for infinite dimensional quantum systems and applications to quantum cryptography
• Post-selection technique for quantum channels with applications to quantum cryptography
• Leftover Hashing Against Quantum Side Information
• Security of continuous-variable quantum key distribution against general attacks
• Multidimensional reconciliation for continuous-variable quantum key distribution
• Characterization of Collective Gaussian Attacks and Security of Coherent-State Quantum Cryptography
• Composability in quantum cryptography
• High Bit Rate Continuous-Variable Quantum Key Distribution
• Reverse Reconciliation Continuous Variable Quantum Key Distribution Based on the Uncertainty Principle

Cited by in corpus (5)

• Coexistence of continuous variable QKD with intense DWDM classical channels
• Finite size analysis of measurement device independent quantum cryptography with continuous variables
• Improving parameter estimation of entropic uncertainty relation in continuous-variable quantum key distribution
• Numerical simulation of the optimal two-mode attacks for two-way continuous-variable quantum cryptography in reverse reconciliation
• Composable security of unidimensional continuous-variable quantum key distribution