Imperfect detectors for adversarial tasks with applications to quantum key distribution
arXiv:2503.06328 · doi:10.22331/q-2026-03-24-2044
Abstract
Security analyses in quantum key distribution (QKD) and other adversarial quantum tasks often assume perfect device models. However, real-world implementations often deviate from these models. Thus, it is important to develop security proofs that account for such deviations from ideality. In this work, we extend the idea of squashing maps to develop a general framework for analysing imperfect threshold detectors, treating uncharacterised device parameters such as dark counts and detection efficiencies as adversarially controlled within some ranges. This approach enables a rigorous worst-case analysis with exactly characterised devices, ensuring security proofs remain valid under realistic conditions. Our results strengthen the connection between theoretical security and practical implementations by introducing a flexible framework for integrating detector imperfections into adversarial quantum protocols.
Fleshed out application to QKD section, including adding comparison with earlier work, adding application to active basis-choice BB84, providing plots for application with the postselection technique, and added reference to "A proof-technique-independent framework for detector imperfections in QKD" which uses these techniques to address correlated imperfections
References in corpus (31)
- Secure quantum key distribution over 421 km of optical fiber
- 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
- Entanglement as precondition for secure quantum key distribution
- Estimates for practical quantum cryptography
- Squashing Models for Optical Measurements in Quantum Communication
- A largely self-contained and complete security proof for quantum key distribution
- Entropy accumulation
- When are correlations quantum? -- Verification and quantification of entanglement by simple measurements
- Security proof for QKD systems with threshold detectors
- Symmetries in Quantum Key Distribution and the Connection between Optimal Attacks and Optimal Cloning
- Finite-key security against coherent attacks in quantum key distribution
- Security of quantum key distribution with arbitrary individual imperfections
- Squashing model for detectors and applications to quantum key distribution protocols
- Dimension Reduction in Quantum Key Distribution for Continuous- and Discrete-Variable Protocols
- Security proof of practical quantum key distribution with detection-efficiency mismatch
- Security of quantum key distribution with intensity correlations
- Entanglement verification with realistic measurement devices via squashing operations
- Generalised entropy accumulation
- Security of quantum key distribution with imperfect phase randomisation
- Security of quantum key distribution with detection-efficiency mismatch in the multiphoton case
- Imperfect Phase-Randomisation and Generalised Decoy-State Quantum Key Distribution
- Postselection technique for optical Quantum Key Distribution with improved de Finetti reductions
- Improving key rates of the unbalanced phase-encoded BB84 protocol using the flag-state squashing model
- Entanglement verification with detection-efficiency mismatch
- Squash Operator and Symmetry
- Security framework for quantum key distribution with imperfect sources
- Quantum key distribution with imperfectly isolated devices
- Improved Decoy-state and Flag-state Squashing Methods
- Finite-size analysis of prepare-and-measure and decoy-state QKD via entropy accumulation
- Quantum-secure multiparty deep learning