Jan Leśniak

Leśniak in 1976 told historian Richard Woytak that, beginning in fall 1935, he received intelligence whose source he had not been informed of and which in fact came from decryption of German Enigma messages by the Polish General Staff's Cipher Bureau.

Like British and American officers who would during World War II receive Ultra intelligence gleaned from Enigma decrypts, then-Major Leśniak began questioning its reliability.

There was less information on the air force, but a great deal on the navy, e.g. movements of naval ships putting out from Kiel and into the Baltic Sea.

The Enigma decrypts helped Polish intelligence build up before the outbreak of World War II a remarkably (95%) complete picture of the German military order of battle and of her mobilization preparations.

Władysław Kozaczuk, Enigma: How the German Machine Cipher Was Broken, and How It Was Read by the Allies in World War Two, edited and translated by Christopher Kasparek, Frederick, MD, University Publications of America, 1984, pp.