Simple protocol for secure decoy-state quantum key distribution with a loosely controlled source

Abstract

The method of decoy-state quantum key distribution (QKD) requests different intensities of light pulses. Existing theory has assumed exact control of intensities. Here we propose a simple protocol which is secure and efficient even there are errors in intensity control. In our protocol, decoy pulses and signal pulses are generated from the same father pulses with a two-value attenuation. Given the upper bound of fluctuation of the father pulses, our protocol is secure provided that the two-value attenuation is done exactly. We propose to use unbalanced beam-splitters for a stable attenuation. Given that the intensity error is bounded by $\pm 5$, with the same key rate, our method can achieve a secure distance only 1 km shorter than that of an ideal protocol with exactly controlled source.

References in corpus (3)

• Quantum key distribution over 122 km of standard telecom fiber
• Experimental Long-Distance Decoy-State Quantum Key Distribution Based On Polarization Encoding
• Long distance decoy state quantum key distribution in optical fiber

Cited by in corpus (8)

• General theory of decoy-state quantum cryptography with source errors
• Secure and efficient decoy-state quantum key distribution with inexact pulse intensities
• General theory for decoy-state quantum key distribution with arbitrary number of intensities
• Decoy State Quantum Key Distribution With Modified Coherent State
• Exact minimum and maximum of yield with a finite number of decoy light intensities
• Effect of detector dead-times on the security evaluation of differential-phase-shift quantum key distribution against sequential attacks
• Decoy states for quantum key distribution based on decoherence-free subspaces
• Recent developments in quantum key distribution: theory and practice