Cipher war

The work of the Polish radio intelligence played a crucial part in securing Polish victory. One year before the Battle of Warsaw, Lieutenant iJan Kowalewski was the first person to crack the Bolshevik code. The work of the radio intelligence was bolstered by the contributions outstanding mathematicians from Warsaw University and the University of Lwów as well as by a network of cryptanalytic cells in Polish staffs on the front organised by Kowalewski. Thanks to the radio intelligence, Poles knew everything about the enemy’s movements and intentions: from the borders of Poland to Siberia; and from the Polar Circle to the Caucasus, which allowed them to react in advance. Such was the Poles’ proficiency in decryption, that they were able to read the Bolshevik messages faster than the Russians.

The Comb
a surprising weapon
in the Polish Arsenal

Jan Kowalewski deciphered the Bolshevik code by moving a comb with broken teeth across a fragment of a cipher text, looking for a sequence where a pair of digits (the marking of a letter) would repeat with equal frequency. That’s how Kowalewski found the Russian word “division” [дивизия]i. Kowalewski’s idea was inspired by Edgar Alan Poe’s story “The Gold-Bug”i.

Be like Jan Kowalewski, find the word “division”ивизия] by moving the comb across the coded message. Note that in the word “дивизия” , “и” appears at regular intervals.

25435467101450145012767492843298
Move the comb
Move the comb

Look for the proper frequencies by turning the dial left or right. When you hear a Bolshevik dispatch (in Morse code) press the jamming button, to jam the message.

Turn left

Turn right

OFF

Jamming switch

Radio static

Jamming

During the Battle of Warsaw, not only was the Polish radio intelligence deciphering the enemy’s messages, but they also jammed radio communications by broadcasting on the same frequency.



“At the radio station key at the Citadel, radio telegraphers were working in shifts and broadcasting non-stop for 36 hours during the Battle of Warsaw. We had to find a text long enough for consecutive radio telegraphers to have something to broadcast. (...) We settled on the Bible”.



Stefan Jasiński’s recollections

scroll-iconscroll-icon