  The aura of mystery surrounding quantum physics makes it difficult to advance
quantum technologies. Demystification requires methodological techniques that
explain the basics of quantum technologies without metaphors and abstract
mathematics. The article provides an example of such an explanation for the
BB84 quantum key distribution protocol based on phase coding. This allows you
to seamlessly get acquainted with the real cryptographic installation QRate,
used at the WorldSkills competition in the competence of "Quantum
Technologies".
