  This note presents a method of public key distribution using quantum
communication of n photons that simultaneously provides a high probability that
the bits have not been tampered. It is a three-state variant of the quantum
method of Bennett and Brassard (BB84) where the transmission states have been
decreased from 4 to 3 and the detector states have been increased from 2 to 3.
Under certain assumptions regarding method of attack, it provides superior
performance (in terms of the number of usable key bits) for n < 18 m, where m
is the number of key bits used to verify the integrity of the process in the
BB84-protocol.
