Security of differential phase shift QKD from relativistic principles

Abstract

The design of quantum protocols for secure key generation poses many challenges: On the one hand, they need to be practical concerning experimental realisations. On the other hand, their theoretical description must be simple enough to allow for a security proof against all possible attacks. Often, these two requirements are in conflict with each other, and the differential phase shift (DPS) QKD protocol exemplifies these difficulties: It is designed to be implementable with current optical telecommunication technology, which, for this protocol, comes at the cost that many standard security proof techniques do not apply to it. After about 20 years since its invention, this work presents the first full security proof of DPS QKD against general attacks, including finite-size effects. The proof combines techniques from quantum information theory, quantum optics, and relativity. We first give a security proof of a QKD protocol whose security stems from relativistic constraints. We then show that security of DPS QKD can be reduced to security of the relativistic protocol. In addition, we show that coherent attacks on the DPS protocol are, in fact, stronger than collective attacks. Our results have broad implications for the development of secure and reliable quantum communication technologies, as they shed light on the range of applicability of state-of-the-art security proof techniques.

Published version with slightly expanded introduction

References in corpus (35)

• Quantum cryptography: Public key distribution and coin tossing
• Fundamental Limits of Repeaterless Quantum Communications
• General Benchmarks for Quantum Repeaters
• Theoretical framework for quantum networks
• Fundamental rate-loss tradeoff for optical quantum key distribution
• Security in Quantum Cryptography
• Post-selection technique for quantum channels with applications to quantum cryptography
• Quantum Information Processing with Finite Resources -- Mathematical Foundations
• Fast and simple one-way Quantum Key Distribution
• Symmetry implies independence
• Witnessing causal nonseparability
• Squashing Models for Optical Measurements in Quantum Communication
• A largely self-contained and complete security proof for quantum key distribution
• Entropy accumulation
• Security of differential phase shift quantum key distribution against individual attacks
• Security proof for QKD systems with threshold detectors
• Entropy accumulation with improved second-order term
• One-Shot Classical Data Compression with Quantum Side Information and the Distillation of Common Randomness or Secret Keys
• Unconditional Security of Single-Photon Differential Phase Shift Quantum Key Distribution
• Squashing model for detectors and applications to quantum key distribution protocols
• Security of quantum key distribution from generalised entropy accumulation
• Dimension Reduction in Quantum Key Distribution for Continuous- and Discrete-Variable Protocols
• Security proof of practical quantum key distribution with detection-efficiency mismatch
• Improved DIQKD protocols with finite-size analysis
• On the Choi-Jamiolkowski Correspondence in Infinite Dimensions
• Generalised entropy accumulation
• Causal Boxes: Quantum Information-Processing Systems Closed under Composition
• Causal structure in the presence of sectorial constraints, with application to the quantum switch
• Effect of detector dead-times on the security evaluation of differential-phase-shift quantum key distribution against sequential attacks
• Quantum key distribution rates from semidefinite programming
• Relativistic Quantum Cryptography
• Randomness in post-selected events
• Finite-key security analysis of differential-phase-shift quantum key distribution
• Information-theoretic security proof of differential-phase-shift quantum key distribution protocol based on complementarity
• Finite-Key Analysis of Quantum Key Distribution with Characterized Devices Using Entropy Accumulation

Cited by in corpus (6)

• Towards Global Quantum Key Distribution
• Security framework for quantum key distribution with imperfect sources
• Quantum Key Distribution with Imperfections: Recent Advances in Security Proofs
• Security loophole in error verification in quantum key distribution
• Security proofs for practical QKD: variations, techniques, gaps, and limitations
• Explicit attacks on differential phase shift quantum key distribution