CV-MDI-QKD: One-mode Gaussian attacks are not enough

Abstract

The security proof of continuous variable (CV) measurement device independent (MDI) quantum key distribution (QKD) cannot be reduced to the analysis of one-mode Gaussian attacks (in particular, independent entangling-cloner attacks). To stress this point, the present note provides a very simple (almost trivial) argument, showing that there are an infinite number of two-mode Gaussian attacks which cannot be reduced to or simulated by one-mode Gaussian attacks. This result further confirms that the security analysis of CV-MDI-QKD must involve a careful minimization over two-mode attacks as originally performed in [S. Pirandola et al., Nature Photon. 9, 397-402 (2015)].

Brief note. 4 pages, 3 figures

References in corpus (19)

• Experimental loophole-free violation of a Bell inequality using entangled electron spins separated by 1.3 km
• Device-independent security of quantum cryptography against collective attacks
• Fundamental Limits of Repeaterless Quantum Communications
• General Benchmarks for Quantum Repeaters
• Long-Distance Continuous-Variable Quantum Key Distribution over 202.81 km of Fiber
• Distributing Secret Keys with Quantum Continuous Variables: Principle, Security and Implementations
• Direct and Reverse Secret-Key Capacities of a Quantum Channel
• Multidimensional reconciliation for continuous-variable quantum key distribution
• Continuous-variable QKD over 50km commercial fiber
• Theory of channel simulation and bounds for private communication
• Correlation Matrices of Two-Mode Bosonic Systems
• Trusted Noise in Continuous-Variable Quantum Key Distribution: a Threat and a Defense
• Continuous-variable measurement-device-independent quantum key distribution using squeezed states
• Continuous-variable quantum cryptography with an untrusted relay: Detailed security analysis of the symmetric configuration
• Continuous-Variable Quantum Key Distribution with Rateless Reconciliation Protocol
• MDI-QKD: Continuous- versus discrete-variables at metropolitan distances
• Two-way Gaussian quantum cryptography against coherent attacks in direct reconciliation
• General immunity and superadditivity of two-way Gaussian quantum cryptography
• Gaussian two-mode attacks in one-way quantum cryptography