Secure communication is particularly important for people whose job requires confidentiality. Among whom may be: business people concerned about any potential activity of their competitors able to cooperate with people having access to systems and technical infrastructure of national secret service, politicians willing to protect themselves from unauthorized control of political opponents connected with the ruling party, people involved in political propaganda, operating in the area of politics and social changes, such as dissidents or activists fighting for human rights and democracy in countries under authoritarian rule, journalists, lawyers and representatives of other professions in which confidentiality is an integral part of their everyday activity.