A postcard design commemorating Breaking the Enigma cipher

The image depicts a digitally modified photograph of three Polish cryptologists: Henryk Zygalski, Jerzy Różycki, and Marian Rejewski. Mathematicians who successfully cracked the Enigma code. They achieved this using mathematical methods, whereas previously only linguistic methods had been used. Enigma, constructed in the 1920s, was initially intended to conceal commercial information, but it found use in the German armed forces.

Against the background of the digitally reconstructed image is the issue's title, symbolizing the decryption process. The arrangement of typographic elements suggests the order in which individual characters should be read.