NANOSYSTEMS: PHYSICS, CHEMISTRY, MATHEMATICS, 2019, 10 (4), P. 398–401
Analysis of the unambiguous state discrimination with unequal a priori probabilities
A. A. Gaidash – ITMO University, Kronverkskiy, 49, St. Petersburg, 197101, Russia; firstname.lastname@example.org
S. S. Medvedeva – ITMO University, Kronverkskiy, 49, St. Petersburg, 197101, Russia; email@example.com
G. P. Miroshnichenko – ITMO University, Kronverkskiy, 49, St. Petersburg, 197101, Russia
In this paper, we study unambiguous state discrimination regarding advanced attack on phase-coded quantum key distribution protocol. We propose the method of optimal unambiguous state discrimination probability derivation as a function of a priori probabilities for signal states. The expression obtained as an example in case of two signal states explicitly demonstrates the additional term dependent on small deviations from equal a priori probabilities that may take place in real quantum key distribution implementations. Precise estimation of optimal unambiguous state discrimination probability is significant for complete evaluation of quantum key distribution security.
Keywords: quantum key distribution, unambiguous state discrimination.