Explicit attacks on differential phase shift quantum key distribution
arXiv:2305.11822 · doi:10.1007/s44464-026-00036-6
Abstract
In the well-established framework of quantum key distribution (QKD), differential phase shift (DPS) protocols have known information-theoretic security bounds defining tolerable error rates under optimal adversaries. In this work, we revisit the security of 3- and n-pulse DPS QKD by explicitly analyzing two specific, physically implementable individual attacks: minimum error discrimination (MED) and quantum cloning. Using semidefinite programming, we characterize these attacks in detail and quantify their induced quantum bit error rates (QBER) and resulting secure key rates under realistic system assumptions. The critical QBER thresholds for these attacks are approximately 20%, significantly higher than the theoretical lower bounds of 6% for individual and 4% for coherent attacks, indicating these are suboptimal adversarial strategies. This study primarily serves as a practical exercise to benchmark known attacks, providing explicit measures that aid experimental validation, protocol calibration, and risk assessment within current technological capabilities. Additionally, we explore finite-size effects and the effectiveness of phase randomization in weak coherent source-based protocols as protection against unambiguous state discrimination attacks.
arXiv comment43 pages, 11 figures
References in corpus (25)
- Quantum cryptography: Public key distribution and coin tossing
- Simple Proof of Security of the BB84 Quantum Key Distribution Protocol
- Overcoming the rate-distance barrier of quantum key distribution without using quantum repeaters
- Provably Secure and Practical Quantum Key Distribution over 307 km of Optical Fibre
- Security in Quantum Cryptography
- Unambiguous Discrimination Between Linearly-Independent Quantum States
- Quantum cryptography with finite resources: unconditional security bound for discrete-variable protocols with one-way post-processing
- Phase covariant quantum cloning
- Finite-key analysis for practical implementations of quantum key distribution
- Security of differential phase shift quantum key distribution against individual attacks
- Security of Quantum Key Distribution with entangled quNits
- Upper bounds of eavesdropper's performances in finite-length code with decoy method
- Upper Bounds for the Security of two Distributed-Phase Reference Protocols of Quantum Cryptography (Coherent-One-Way and Differential-Phase-Shift)
- Finite-key security against coherent attacks in quantum key distribution
- Unconditional Security of Single-Photon Differential Phase Shift Quantum Key Distribution
- Differential-phase-shift quantum key distribution protocol with small number of random delays
- Linear optics and photodetection achieve near-optimal unambiguous coherent state discrimination
- Finite-key security analysis of differential-phase-shift quantum key distribution
- Superadditive Communication with the Green Machine: A Practical Demonstration of Nonlocality without Entanglement
- Quantum key distribution with simply characterized light sources
- Security of differential phase shift QKD from relativistic principles
- Differential phase encoded measurement-device-independent quantum key distribution
- Equivalence of space and time-bins in DPS-QKD
- On optimal cloning and incompatibility
- Proposal of an eavesdropping experiment for BB84 QKD protocol with 1-3 phase-covariant quantum cloner