Dense coding and safety of quantum communications

Safety of quantum communications is, in the first place, the result of the quantum nature of the signal, sending by the sender Alice to the receiver Bob. But when we discuss the safety of the quantum communications as a whole we have to take into account all objects taking place in the process of creation and communciation of information. One of such object is the sending station, which is a classical one. As such it can be eavesdropped by classical means and this fact can reduce sharply the safety of quantum channel. In this noe we demonstrate, that dense coding and quantum properits of the channel give the possibility to raise the safety of classical sending station against the eavesdropping.