A quantum cloning bound and application to quantum key distribution

Abstract

We introduce a quantum cloning bound which we apply to a straightforward and relatively direct security proof of the prepare-and-measure Bennett-Brassard 1984 (BB84) quantum key distribution (QKD) protocol against collective attacks. The approach we propose is able to handle the practical problem of source and detector alignment imprecisions in a simple way. Specifically, we derive a keyrate bound for a BB84 implementation in which Alice's source emits four given but arbitrary pure states, where the usual equivalence between prepare-and-measure and entanglement-based QKD no longer applies. Our result is similar to a keyrate derived by Marøy et. al. [Phys. Rev. A 82, 032337 (2010)] and generally an improvement over the keyrate derivable from the entropic uncertainty relation in situations where it applies. We also provide a stronger result for a source emitting arbitrary qubit states, and a further improved result if the detector is additionally assumed two dimensional.

References in corpus (8)

• Measurement-device-independent quantum key distribution
• Device-independent security of quantum cryptography against collective attacks
• Distillation of secret key and entanglement from quantum states
• One-sided Device-Independent Quantum Key Distribution: Security, feasibility, and the connection with steering
• Post-selection technique for quantum channels with applications to quantum cryptography
• Semi-device-independent security of one-way quantum key distribution
• A Monogamy-of-Entanglement Game With Applications to Device-Independent Quantum Cryptography
• Effects of preparation and measurement misalignments on the security of the BB84 quantum key distribution protocol

Cited by in corpus (9)

• Numerical approach for unstructured quantum key distribution
• Verifying the quantumness of a channel with an untrusted device
• Device-independent quantum key distribution with asymmetric CHSH inequalities
• Testing dimension and non-classicality in communication networks
• Simple and practical DIQKD security analysis via BB84-type uncertainty relations and Pauli correlation constraints
• Certifying long-range quantum correlations through routed Bell tests
• Semi device independence of the BB84 protocol
• Tight asymptotic key rate for the BB84 protocol with local randomisation and device imprecisions
• Quantum Telecloning on NISQ Computers