By Ayan Biswas, Anindya Banerji, Nijil Lal, Pooja Chandravanshi, Rupesh Kumar, Ravindra P. Singh.
Submitted to arXiv on 17 August 2020.
In this article, we present a proof-of-concept implementation of quantum key distribution protocol based on BB84 with imperfect devices. We show that using coincidence measurements to monitor multiphoton pulses results in a higher secure key rate over longer distances. This key rate is higher than the decoy state protocol, the most popular practical implementation of quantum key distribution protocol based on BB84. In the experiment, we obtained a key rate of 0.053934 ± 0.004088 per signal pulse compared to 0.031051± 0.003303 for decoy-state protocol with similar parameters.