  All known QKD protocols require the parties to discard the results when they
have chosen differen bases. In this paper we show that it is not necessary. We
give examples of QKD protocols that are as safe as standard ones but do not
involve the discarding the results when the bases are different or even that do
not require the announcement of the bases. This leads to greater communication
channel capacities and render some eavesdropping strategies useless but the
most important thing is that they provide us better insight into the general
structures that underlie the quantum cryptography and help to establish the
boundaries of what is possible and what is not.
