Active Basis Choice for Quantum Key Distribution with Entangled States

Quantum key distribution is a method that allows two interlocutors to generate a common random bit sequence (key) and guarantee its secrecy using only open communication channels. QKD protocols can be divided into 2 main types based on the key generation principle: preapare-and-measure, in which the sender (Alice) prepares quantum states, and the recipient (Bob) carries out measurements on them; and entanglement-based protocols, in which an independent source generates entangled two-photon states that are subsequently and symmetrically measured by Alice and Bob. During the work, 3 large independent tasks were completed: a comparative analysis of various experimental configurations of the BBM92 protocol was carried out considering the security requirements; a source of entangled states for the BBM92 protocol has been implemented and quantum key distribution with an active basis choice has been carried out; The B92 protocol with bright reference pulses has been completed and quantum key distribution has also been implemented.