Here we present two new schemes for quantum key distribution (QKD) which neither require entanglement nor require an ideal single photon source. Thus, the proposed protocols can be implemented using realistic single photon sources which are commercially available. The schemes are shown to be secure against multiple attacks (e.g., intercept resend attack and a class of collective attacks). Bounds on the key rate are obtained and it is shown that by applying a certain type of classical pre-processing, the tolerable error limit can be increased. A trade-off between quantum resources used and information revealed to Eve is observed and it's shown that by using slightly more quantum resources it's possible to design protocols having higher efficiency compared to a protocol of the same family that uses a relatively lesser amount of quantum resources. Specifically, in our case, SARG04 protocol is a protocol of the same family and it's clearly shown that the proposed protocols can provide higher efficiency compared to SARG04 at the cost of consumption of more quantum resources.
View on arXiv@article{dutta2025_2212.13089,
title={ New protocols for quantum key distribution with explicit upper and lower bound on secret key rate },
author={ Arindam Dutta and Anirban Pathak },
journal={arXiv preprint arXiv:2212.13089},
year={ 2025 }
}