Study of a Quantum Key Distribution Protocol with Phase-Time Coding Using Simulation Modeling

One of the main applications of quantum communication is quantum key distribution, which solves the problem of secure distribution of cryptographic keys between remote users. This paper investigates the performance of a phase-time coding quantum key distribution protocol belonging to the BB84 protocol family. We construct a simulation model that takes into account the peculiarities of hardware operation and physical properties of the transmission medium. Computational experiments with this model have shown that stable operation of the considered protocol is possible over communication lines up to 210 km long, but this parameter can be improved by constructing a more efficient error-correcting code.