Ciphertexts are undoubtedly an important element of the sources of diplomatic provenance. They allowed quick, concise and secure transfer of information and opinions which could not have been postponed. With regard to Lusatia, they are an interesting supplement to the picture of Polish interests in the Sorbian national movement. The study presents dispatches incoming and outgoing from the Legation of the Republic of Poland in Prague, the Embassy of the Republic of Poland in Belgrade and the Polish Military Mission in Berlin.