npj Quantum Information (Sep 2022)
Long-range QKD without trusted nodes is not possible with current technology
Abstract
A recently published patent ( https://www.ipo.gov.uk/p-ipsum/Case/PublicationNumber/GB2590064 ) has claimed the development of a novel quantum key distribution protocol purporting to achieve long-range quantum security without trusted nodes and without use of quantum repeaters. Here we present a straightforward analysis of this claim, and reach the conclusion that it is largely unfounded.