Qubit-based clock synchronization for QKD systems using a Bayesian approach
arXiv:2107.01304 · doi:10.3390/e23080988
Abstract
Quantum key distribution (QKD) systems provide a method for two users to exchange a provably secure key. Synchronizing the users' clocks is an essential step before a secure key can be distilled. Qubit-based synchronization protocols directly use the transmitted quantum states to achieve synchronization and thus avoid the need for additional classical synchronization hardware. Previous qubit-based synchronization protocols sacrifice secure key either directly or indirectly, and all known qubit-based synchronization protocols do not efficiently use all publicly available information published by the users. Here, we introduce a Bayesian probabilistic algorithm that incorporates all published information to efficiently find the clock offset without sacrificing any secure key. Additionally, the output of the algorithm is a probability, which allows us to quantify our confidence in the synchronization. For demonstration purposes, we present a model system with accompanying simulations of an efficient three-state BB84 prepare-and-measure protocol with decoy states. We use our algorithm to exploit the correlations between Alice's published basis and mean photon number choices and Bob's measurement outcomes to probabilistically determine the most likely clock offset. We find that we can achieve a 95 percent synchronization confidence in only 4,140 communication bin widths, meaning we can tolerate clock drift approaching 1 part in 4,140 in this example when simulating this system with a dark count probability per communication bin width of 8e-4 and a received mean photon number of 0.01.
arXiv comment14 pages, 4 figures
References in corpus (20)
- Quantum cryptography: Public key distribution and coin tossing
- Decoy State Quantum Key Distribution
- Field test of quantum key distribution in the Tokyo QKD Network
- Provably Secure and Practical Quantum Key Distribution over 307 km of Optical Fibre
- Concise Security Bounds for Practical Decoy-State Quantum Key Distribution
- Field and long-term demonstration of a wide area quantum key distribution network
- 200km Decoy-state quantum key distribution with photon polarization
- Loss-tolerant quantum cryptography with imperfect sources
- Ultra-high bandwidth quantum secured data transmission
- A fast and versatile QKD system with hardware key distillation and wavelength multiplexing
- Upper bounds of eavesdropper's performances in finite-length code with decoy method
- Simple Quantum Key Distribution with qubit-based synchronization and a self-compensating polarization encoder
- Clock synchronization by remote detection of correlated photon pairs
- Fast and simple qubit-based synchronization for quantum key distribution
- Adaptive Real Time Selection for Quantum Key Distribution in Lossy and Turbulent Free-Space Channels
- Experimental quantum key distribution with simulated ground-to-satellite photon losses and processing limitations
- Resource-effective Quantum Key Distribution: a field-trial in Padua city center
- Securing quantum key distribution systems using fewer states
- Secure and efficient synchronization scheme for quantum key distribution
- A universal, plug-and-play synchronisation scheme for practical quantum networks