Phase error rate estimation in QKD with imperfect detectors
arXiv:2408.17349 · doi:10.22331/q-2025-12-11-1937
Abstract
We present a finite-size security proof of the decoy-state BB84 QKD protocol against coherent attacks, using entropic uncertainty relations, for imperfect detectors. We apply this result to the case of detectors with imperfectly characterized basis-efficiency mismatch. Our proof works by obtaining a suitable bound on the phase error rate, without requiring any new modifications to the protocol steps or hardware. It is applicable to imperfectly characterized detectors, and only requires the maximum relative difference in detection efficiencies and dark count rates of the detectors to be characterized. Moreover, our proof allows Eve to choose detector efficiencies and dark count rates in their allowed ranges in each round, thereby addressing an important problem of detector side channels. We prove security in the variable-length framework, where users are allowed to adaptively determine the length of key to be produced, and number of bits to be used for error-correction, based on observations made during the protocol. We quantitatively demonstrate the effect of basis-efficiency mismatch by applying our results to the decoy-state BB84 protocol.
Accepted in Quantum. Fixed typos, minor restructuring of manuscript (moved discussion of related work to introduction), added a few relevant citations
References in corpus (41)
- Decoy State Quantum Key Distribution
- Measurement-device-independent quantum key distribution
- Quantum Key Distribution with High Loss: Toward Global Secure Communication
- Hacking commercial quantum cryptography systems by tailored bright illumination
- Practical Decoy State for Quantum Key Distribution
- Tight Finite-Key Analysis for Quantum Cryptography
- Trojan Horse attacks on Quantum Key Distribution systems
- Full-field implementation of a perfect eavesdropper on a quantum cryptography system
- The Uncertainty Relation for Smooth Entropies
- Finite-key analysis for measurement-device-independent quantum key distribution
- Concise Security Bounds for Practical Decoy-State Quantum Key Distribution
- Security in Quantum Cryptography
- Effects of detector efficiency mismatch on security of quantum cryptosystems
- Post-selection technique for quantum channels with applications to quantum cryptography
- Entanglement as precondition for secure quantum key distribution
- Quantum Information Processing with Finite Resources -- Mathematical Foundations
- Practical issues in quantum-key-distribution post-processing
- Loss-tolerant quantum cryptography with imperfect sources
- Finite-key analysis on the 1-decoy state QKD protocol
- A largely self-contained and complete security proof for quantum key distribution
- Reliable numerical key rates for quantum key distribution
- Security loophole in free-space quantum key distribution due to spatial-mode detector-efficiency mismatch
- Concise and Tight Security Analysis of the Bennett-Brassard 1984 Protocol with Finite Key Lengths
- Symmetries in Quantum Key Distribution and the Connection between Optimal Attacks and Optimal Cloning
- Security analysis of the decoy method with the Bennett-Brassard 1984 protocol for finite key lengths
- Security of quantum key distribution with arbitrary individual imperfections
- Tight finite-key security for twin-field quantum key distribution
- Security proof of practical quantum key distribution with detection-efficiency mismatch
- Detector decoy quantum key distribution
- Security of quantum key distribution with detection-efficiency mismatch in the single-photon case: Tight bounds
- Sifting attacks in finite-size quantum key distribution
- Security of quantum key distribution with detection-efficiency mismatch in the multiphoton case
- Security Proof for Variable-Length Quantum Key Distribution
- Postselection technique for optical Quantum Key Distribution with improved de Finetti reductions
- Leftover hashing from quantum error correction: Unifying the two approaches to the security proof of quantum key distribution
- Entanglement verification with detection-efficiency mismatch
- Security framework for quantum key distribution with imperfect sources
- Improved Decoy-state and Flag-state Squashing Methods
- Quantum Key Distribution with Basis-Dependent Detection Probability
- Loss-tolerant quantum key distribution with detection efficiency mismatch
- Finite-key security analysis of the decoy-state BB84 QKD with passive measurement