Yt. Mazurenko et al., Quantum transmission of information with the help of subcarrier frequency.Application to quantum cryptography, OPT SPECTRO, 86(2), 1999, pp. 145-147
The term "key distribution" is used to denote a communication process, as a
result of which two legal users of a communication channel (Alice and Bob)
get one and the same random binary succession. The succession obtained can
be used then as a cryptographic key for exchanging information between Ali
ce and Bob. Therefore, the probability that other persons are not familiar
with the key should be close to unity [1].