Experimental comparison between one-decoy and two-decoy implementations of Bennett-Brassard 1984 quantum cryptography protocol

Abstract

The decoy-state method allows the use of weak coherent pulses in quantum cryptography, and to date, various strategies for the decoy state have been proposed. Here, we experimentally compare the secret key generation rates between the one-decoy and two-decoy implementations of the Bennett-Brassard 1984 (BB84) quantum key distribution protocol through a 3.1-km optical fiber at 780 nm. Once the parameters of the experimental setup are optimized for the maximal secret key generation rate for each implementation, it is found that the two-decoy implementation outperforms the one-decoy implementation.